class-wp-customize-widgets.php 69.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211
<?php
/**
 * WordPress Customize Widgets classes
 *
 * @package WordPress
 * @subpackage Customize
 * @since 3.9.0
 */

/**
 * Customize Widgets class.
 *
 * Implements widget management in the Customizer.
 *
 * @since 3.9.0
 *
 * @see WP_Customize_Manager
 */
final class WP_Customize_Widgets {

	/**
	 * WP_Customize_Manager instance.
	 *
	 * @since 3.9.0
	 * @var WP_Customize_Manager
	 */
	public $manager;

	/**
	 * All id_bases for widgets defined in core.
	 *
	 * @since 3.9.0
	 * @var array
	 */
	protected $core_widget_id_bases = array(
		'archives',
		'calendar',
		'categories',
		'custom_html',
		'links',
		'media_audio',
		'media_image',
		'media_video',
		'meta',
		'nav_menu',
		'pages',
		'recent-comments',
		'recent-posts',
		'rss',
		'search',
		'tag_cloud',
		'text',
	);

	/**
	 * @since 3.9.0
	 * @var array
	 */
	protected $rendered_sidebars = array();

	/**
	 * @since 3.9.0
	 * @var array
	 */
	protected $rendered_widgets = array();

	/**
	 * @since 3.9.0
	 * @var array
	 */
	protected $old_sidebars_widgets = array();

	/**
	 * Mapping of widget ID base to whether it supports selective refresh.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $selective_refreshable_widgets;

	/**
	 * Mapping of setting type to setting ID pattern.
	 *
	 * @since 4.2.0
	 * @var array
	 */
	protected $setting_id_patterns = array(
		'widget_instance' => '/^widget_(?P<id_base>.+?)(?:\[(?P<widget_number>\d+)\])?$/',
		'sidebar_widgets' => '/^sidebars_widgets\[(?P<sidebar_id>.+?)\]$/',
	);

	/**
	 * Initial loader.
	 *
	 * @since 3.9.0
	 *
	 * @param WP_Customize_Manager $manager Customizer bootstrap instance.
	 */
	public function __construct( $manager ) {
		$this->manager = $manager;

		// See https://github.com/xwp/wp-customize-snapshots/blob/962586659688a5b1fd9ae93618b7ce2d4e7a421c/php/class-customize-snapshot-manager.php#L420-L449
		add_filter( 'customize_dynamic_setting_args', array( $this, 'filter_customize_dynamic_setting_args' ), 10, 2 );
		add_action( 'widgets_init', array( $this, 'register_settings' ), 95 );
		add_action( 'customize_register', array( $this, 'schedule_customize_register' ), 1 );

		// Skip remaining hooks when the user can't manage widgets anyway.
		if ( ! current_user_can( 'edit_theme_options' ) ) {
			return;
		}

		add_action( 'wp_loaded', array( $this, 'override_sidebars_widgets_for_theme_switch' ) );
		add_action( 'customize_controls_init', array( $this, 'customize_controls_init' ) );
		add_action( 'customize_controls_enqueue_scripts', array( $this, 'enqueue_scripts' ) );
		add_action( 'customize_controls_print_styles', array( $this, 'print_styles' ) );
		add_action( 'customize_controls_print_scripts', array( $this, 'print_scripts' ) );
		add_action( 'customize_controls_print_footer_scripts', array( $this, 'print_footer_scripts' ) );
		add_action( 'customize_controls_print_footer_scripts', array( $this, 'output_widget_control_templates' ) );
		add_action( 'customize_preview_init', array( $this, 'customize_preview_init' ) );
		add_filter( 'customize_refresh_nonces', array( $this, 'refresh_nonces' ) );
		add_filter( 'should_load_block_editor_scripts_and_styles', array( $this, 'should_load_block_editor_scripts_and_styles' ) );

		add_action( 'dynamic_sidebar', array( $this, 'tally_rendered_widgets' ) );
		add_filter( 'is_active_sidebar', array( $this, 'tally_sidebars_via_is_active_sidebar_calls' ), 10, 2 );
		add_filter( 'dynamic_sidebar_has_widgets', array( $this, 'tally_sidebars_via_dynamic_sidebar_calls' ), 10, 2 );

		// Selective Refresh.
		add_filter( 'customize_dynamic_partial_args', array( $this, 'customize_dynamic_partial_args' ), 10, 2 );
		add_action( 'customize_preview_init', array( $this, 'selective_refresh_init' ) );
	}

	/**
	 * List whether each registered widget can be use selective refresh.
	 *
	 * If the theme does not support the customize-selective-refresh-widgets feature,
	 * then this will always return an empty array.
	 *
	 * @since 4.5.0
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 *
	 * @return array Mapping of id_base to support. If theme doesn't support
	 *               selective refresh, an empty array is returned.
	 */
	public function get_selective_refreshable_widgets() {
		global $wp_widget_factory;
		if ( ! current_theme_supports( 'customize-selective-refresh-widgets' ) ) {
			return array();
		}
		if ( ! isset( $this->selective_refreshable_widgets ) ) {
			$this->selective_refreshable_widgets = array();
			foreach ( $wp_widget_factory->widgets as $wp_widget ) {
				$this->selective_refreshable_widgets[ $wp_widget->id_base ] = ! empty( $wp_widget->widget_options['customize_selective_refresh'] );
			}
		}
		return $this->selective_refreshable_widgets;
	}

	/**
	 * Determines if a widget supports selective refresh.
	 *
	 * @since 4.5.0
	 *
	 * @param string $id_base Widget ID Base.
	 * @return bool Whether the widget can be selective refreshed.
	 */
	public function is_widget_selective_refreshable( $id_base ) {
		$selective_refreshable_widgets = $this->get_selective_refreshable_widgets();
		return ! empty( $selective_refreshable_widgets[ $id_base ] );
	}

	/**
	 * Retrieves the widget setting type given a setting ID.
	 *
	 * @since 4.2.0
	 *
	 * @param string $setting_id Setting ID.
	 * @return string|void Setting type.
	 */
	protected function get_setting_type( $setting_id ) {
		static $cache = array();
		if ( isset( $cache[ $setting_id ] ) ) {
			return $cache[ $setting_id ];
		}
		foreach ( $this->setting_id_patterns as $type => $pattern ) {
			if ( preg_match( $pattern, $setting_id ) ) {
				$cache[ $setting_id ] = $type;
				return $type;
			}
		}
	}

	/**
	 * Inspects the incoming customized data for any widget settings, and dynamically adds
	 * them up-front so widgets will be initialized properly.
	 *
	 * @since 4.2.0
	 */
	public function register_settings() {
		$widget_setting_ids   = array();
		$incoming_setting_ids = array_keys( $this->manager->unsanitized_post_values() );
		foreach ( $incoming_setting_ids as $setting_id ) {
			if ( ! is_null( $this->get_setting_type( $setting_id ) ) ) {
				$widget_setting_ids[] = $setting_id;
			}
		}
		if ( $this->manager->doing_ajax( 'update-widget' ) && isset( $_REQUEST['widget-id'] ) ) {
			$widget_setting_ids[] = $this->get_setting_id( wp_unslash( $_REQUEST['widget-id'] ) );
		}

		$settings = $this->manager->add_dynamic_settings( array_unique( $widget_setting_ids ) );

		if ( $this->manager->settings_previewed() ) {
			foreach ( $settings as $setting ) {
				$setting->preview();
			}
		}
	}

	/**
	 * Determines the arguments for a dynamically-created setting.
	 *
	 * @since 4.2.0
	 *
	 * @param false|array $args       The arguments to the WP_Customize_Setting constructor.
	 * @param string      $setting_id ID for dynamic setting, usually coming from `$_POST['customized']`.
	 * @return array|false Setting arguments, false otherwise.
	 */
	public function filter_customize_dynamic_setting_args( $args, $setting_id ) {
		if ( $this->get_setting_type( $setting_id ) ) {
			$args = $this->get_setting_args( $setting_id );
		}
		return $args;
	}

	/**
	 * Retrieves an unslashed post value or return a default.
	 *
	 * @since 3.9.0
	 *
	 * @param string $name          Post value.
	 * @param mixed  $default_value Default post value.
	 * @return mixed Unslashed post value or default value.
	 */
	protected function get_post_value( $name, $default_value = null ) {
		if ( ! isset( $_POST[ $name ] ) ) {
			return $default_value;
		}

		return wp_unslash( $_POST[ $name ] );
	}

	/**
	 * Override sidebars_widgets for theme switch.
	 *
	 * When switching a theme via the Customizer, supply any previously-configured
	 * sidebars_widgets from the target theme as the initial sidebars_widgets
	 * setting. Also store the old theme's existing settings so that they can
	 * be passed along for storing in the sidebars_widgets theme_mod when the
	 * theme gets switched.
	 *
	 * @since 3.9.0
	 *
	 * @global array $sidebars_widgets
	 * @global array $_wp_sidebars_widgets
	 */
	public function override_sidebars_widgets_for_theme_switch() {
		global $sidebars_widgets;

		if ( $this->manager->doing_ajax() || $this->manager->is_theme_active() ) {
			return;
		}

		$this->old_sidebars_widgets = wp_get_sidebars_widgets();
		add_filter( 'customize_value_old_sidebars_widgets_data', array( $this, 'filter_customize_value_old_sidebars_widgets_data' ) );
		$this->manager->set_post_value( 'old_sidebars_widgets_data', $this->old_sidebars_widgets ); // Override any value cached in changeset.

		// retrieve_widgets() looks at the global $sidebars_widgets.
		$sidebars_widgets = $this->old_sidebars_widgets;
		$sidebars_widgets = retrieve_widgets( 'customize' );
		add_filter( 'option_sidebars_widgets', array( $this, 'filter_option_sidebars_widgets_for_theme_switch' ), 1 );
		// Reset global cache var used by wp_get_sidebars_widgets().
		unset( $GLOBALS['_wp_sidebars_widgets'] );
	}

	/**
	 * Filters old_sidebars_widgets_data Customizer setting.
	 *
	 * When switching themes, filter the Customizer setting old_sidebars_widgets_data
	 * to supply initial $sidebars_widgets before they were overridden by retrieve_widgets().
	 * The value for old_sidebars_widgets_data gets set in the old theme's sidebars_widgets
	 * theme_mod.
	 *
	 * @since 3.9.0
	 *
	 * @see WP_Customize_Widgets::handle_theme_switch()
	 *
	 * @param array $old_sidebars_widgets
	 * @return array
	 */
	public function filter_customize_value_old_sidebars_widgets_data( $old_sidebars_widgets ) {
		return $this->old_sidebars_widgets;
	}

	/**
	 * Filters sidebars_widgets option for theme switch.
	 *
	 * When switching themes, the retrieve_widgets() function is run when the Customizer initializes,
	 * and then the new sidebars_widgets here get supplied as the default value for the sidebars_widgets
	 * option.
	 *
	 * @since 3.9.0
	 *
	 * @see WP_Customize_Widgets::handle_theme_switch()
	 * @global array $sidebars_widgets
	 *
	 * @param array $sidebars_widgets
	 * @return array
	 */
	public function filter_option_sidebars_widgets_for_theme_switch( $sidebars_widgets ) {
		$sidebars_widgets                  = $GLOBALS['sidebars_widgets'];
		$sidebars_widgets['array_version'] = 3;
		return $sidebars_widgets;
	}

	/**
	 * Ensures all widgets get loaded into the Customizer.
	 *
	 * Note: these actions are also fired in wp_ajax_update_widget().
	 *
	 * @since 3.9.0
	 */
	public function customize_controls_init() {
		/** This action is documented in wp-admin/includes/ajax-actions.php */
		do_action( 'load-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/includes/ajax-actions.php */
		do_action( 'widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/widgets.php */
		do_action( 'sidebar_admin_setup' );
	}

	/**
	 * Ensures widgets are available for all types of previews.
	 *
	 * When in preview, hook to {@see 'customize_register'} for settings after WordPress is loaded
	 * so that all filters have been initialized (e.g. Widget Visibility).
	 *
	 * @since 3.9.0
	 */
	public function schedule_customize_register() {
		if ( is_admin() ) {
			$this->customize_register();
		} else {
			add_action( 'wp', array( $this, 'customize_register' ) );
		}
	}

	/**
	 * Registers Customizer settings and controls for all sidebars and widgets.
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_widgets
	 * @global array $wp_registered_widget_controls
	 * @global array $wp_registered_sidebars
	 */
	public function customize_register() {
		global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_sidebars;

		$use_widgets_block_editor = wp_use_widgets_block_editor();

		add_filter( 'sidebars_widgets', array( $this, 'preview_sidebars_widgets' ), 1 );

		$sidebars_widgets = array_merge(
			array( 'wp_inactive_widgets' => array() ),
			array_fill_keys( array_keys( $wp_registered_sidebars ), array() ),
			wp_get_sidebars_widgets()
		);

		$new_setting_ids = array();

		/*
		 * Register a setting for all widgets, including those which are active,
		 * inactive, and orphaned since a widget may get suppressed from a sidebar
		 * via a plugin (like Widget Visibility).
		 */
		foreach ( array_keys( $wp_registered_widgets ) as $widget_id ) {
			$setting_id   = $this->get_setting_id( $widget_id );
			$setting_args = $this->get_setting_args( $setting_id );
			if ( ! $this->manager->get_setting( $setting_id ) ) {
				$this->manager->add_setting( $setting_id, $setting_args );
			}
			$new_setting_ids[] = $setting_id;
		}

		/*
		 * Add a setting which will be supplied for the theme's sidebars_widgets
		 * theme_mod when the theme is switched.
		 */
		if ( ! $this->manager->is_theme_active() ) {
			$setting_id   = 'old_sidebars_widgets_data';
			$setting_args = $this->get_setting_args(
				$setting_id,
				array(
					'type'  => 'global_variable',
					'dirty' => true,
				)
			);
			$this->manager->add_setting( $setting_id, $setting_args );
		}

		$this->manager->add_panel(
			'widgets',
			array(
				'type'                     => 'widgets',
				'title'                    => __( 'Widgets' ),
				'description'              => __( 'Widgets are independent sections of content that can be placed into widgetized areas provided by your theme (commonly called sidebars).' ),
				'priority'                 => 110,
				'active_callback'          => array( $this, 'is_panel_active' ),
				'auto_expand_sole_section' => true,
				'theme_supports'           => 'widgets',
			)
		);

		foreach ( $sidebars_widgets as $sidebar_id => $sidebar_widget_ids ) {
			if ( empty( $sidebar_widget_ids ) ) {
				$sidebar_widget_ids = array();
			}

			$is_registered_sidebar = is_registered_sidebar( $sidebar_id );
			$is_inactive_widgets   = ( 'wp_inactive_widgets' === $sidebar_id );
			$is_active_sidebar     = ( $is_registered_sidebar && ! $is_inactive_widgets );

			// Add setting for managing the sidebar's widgets.
			if ( $is_registered_sidebar || $is_inactive_widgets ) {
				$setting_id   = sprintf( 'sidebars_widgets[%s]', $sidebar_id );
				$setting_args = $this->get_setting_args( $setting_id );
				if ( ! $this->manager->get_setting( $setting_id ) ) {
					if ( ! $this->manager->is_theme_active() ) {
						$setting_args['dirty'] = true;
					}
					$this->manager->add_setting( $setting_id, $setting_args );
				}
				$new_setting_ids[] = $setting_id;

				// Add section to contain controls.
				$section_id = sprintf( 'sidebar-widgets-%s', $sidebar_id );
				if ( $is_active_sidebar ) {

					$section_args = array(
						'title'      => $wp_registered_sidebars[ $sidebar_id ]['name'],
						'priority'   => array_search( $sidebar_id, array_keys( $wp_registered_sidebars ), true ),
						'panel'      => 'widgets',
						'sidebar_id' => $sidebar_id,
					);

					if ( $use_widgets_block_editor ) {
						$section_args['description'] = '';
					} else {
						$section_args['description'] = $wp_registered_sidebars[ $sidebar_id ]['description'];
					}

					/**
					 * Filters Customizer widget section arguments for a given sidebar.
					 *
					 * @since 3.9.0
					 *
					 * @param array      $section_args Array of Customizer widget section arguments.
					 * @param string     $section_id   Customizer section ID.
					 * @param int|string $sidebar_id   Sidebar ID.
					 */
					$section_args = apply_filters( 'customizer_widgets_section_args', $section_args, $section_id, $sidebar_id );

					$section = new WP_Customize_Sidebar_Section( $this->manager, $section_id, $section_args );
					$this->manager->add_section( $section );

					if ( $use_widgets_block_editor ) {
						$control = new WP_Sidebar_Block_Editor_Control(
							$this->manager,
							$setting_id,
							array(
								'section'     => $section_id,
								'sidebar_id'  => $sidebar_id,
								'label'       => $section_args['title'],
								'description' => $section_args['description'],
							)
						);
					} else {
						$control = new WP_Widget_Area_Customize_Control(
							$this->manager,
							$setting_id,
							array(
								'section'    => $section_id,
								'sidebar_id' => $sidebar_id,
								'priority'   => count( $sidebar_widget_ids ), // place 'Add Widget' and 'Reorder' buttons at end.
							)
						);
					}

					$this->manager->add_control( $control );

					$new_setting_ids[] = $setting_id;
				}
			}

			if ( ! $use_widgets_block_editor ) {
				// Add a control for each active widget (located in a sidebar).
				foreach ( $sidebar_widget_ids as $i => $widget_id ) {

					// Skip widgets that may have gone away due to a plugin being deactivated.
					if ( ! $is_active_sidebar || ! isset( $wp_registered_widgets[ $widget_id ] ) ) {
						continue;
					}

					$registered_widget = $wp_registered_widgets[ $widget_id ];
					$setting_id        = $this->get_setting_id( $widget_id );
					$id_base           = $wp_registered_widget_controls[ $widget_id ]['id_base'];

					$control = new WP_Widget_Form_Customize_Control(
						$this->manager,
						$setting_id,
						array(
							'label'          => $registered_widget['name'],
							'section'        => $section_id,
							'sidebar_id'     => $sidebar_id,
							'widget_id'      => $widget_id,
							'widget_id_base' => $id_base,
							'priority'       => $i,
							'width'          => $wp_registered_widget_controls[ $widget_id ]['width'],
							'height'         => $wp_registered_widget_controls[ $widget_id ]['height'],
							'is_wide'        => $this->is_wide_widget( $widget_id ),
						)
					);
					$this->manager->add_control( $control );
				}
			}
		}

		if ( $this->manager->settings_previewed() ) {
			foreach ( $new_setting_ids as $new_setting_id ) {
				$this->manager->get_setting( $new_setting_id )->preview();
			}
		}
	}

	/**
	 * Determines whether the widgets panel is active, based on whether there are sidebars registered.
	 *
	 * @since 4.4.0
	 *
	 * @see WP_Customize_Panel::$active_callback
	 *
	 * @global array $wp_registered_sidebars
	 * @return bool Active.
	 */
	public function is_panel_active() {
		global $wp_registered_sidebars;
		return ! empty( $wp_registered_sidebars );
	}

	/**
	 * Converts a widget_id into its corresponding Customizer setting ID (option name).
	 *
	 * @since 3.9.0
	 *
	 * @param string $widget_id Widget ID.
	 * @return string Maybe-parsed widget ID.
	 */
	public function get_setting_id( $widget_id ) {
		$parsed_widget_id = $this->parse_widget_id( $widget_id );
		$setting_id       = sprintf( 'widget_%s', $parsed_widget_id['id_base'] );

		if ( ! is_null( $parsed_widget_id['number'] ) ) {
			$setting_id .= sprintf( '[%d]', $parsed_widget_id['number'] );
		}
		return $setting_id;
	}

	/**
	 * Determines whether the widget is considered "wide".
	 *
	 * Core widgets which may have controls wider than 250, but can still be shown
	 * in the narrow Customizer panel. The RSS and Text widgets in Core, for example,
	 * have widths of 400 and yet they still render fine in the Customizer panel.
	 *
	 * This method will return all Core widgets as being not wide, but this can be
	 * overridden with the {@see 'is_wide_widget_in_customizer'} filter.
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_widget_controls
	 *
	 * @param string $widget_id Widget ID.
	 * @return bool Whether or not the widget is a "wide" widget.
	 */
	public function is_wide_widget( $widget_id ) {
		global $wp_registered_widget_controls;

		$parsed_widget_id = $this->parse_widget_id( $widget_id );
		$width            = $wp_registered_widget_controls[ $widget_id ]['width'];
		$is_core          = in_array( $parsed_widget_id['id_base'], $this->core_widget_id_bases, true );
		$is_wide          = ( $width > 250 && ! $is_core );

		/**
		 * Filters whether the given widget is considered "wide".
		 *
		 * @since 3.9.0
		 *
		 * @param bool   $is_wide   Whether the widget is wide, Default false.
		 * @param string $widget_id Widget ID.
		 */
		return apply_filters( 'is_wide_widget_in_customizer', $is_wide, $widget_id );
	}

	/**
	 * Converts a widget ID into its id_base and number components.
	 *
	 * @since 3.9.0
	 *
	 * @param string $widget_id Widget ID.
	 * @return array Array containing a widget's id_base and number components.
	 */
	public function parse_widget_id( $widget_id ) {
		$parsed = array(
			'number'  => null,
			'id_base' => null,
		);

		if ( preg_match( '/^(.+)-(\d+)$/', $widget_id, $matches ) ) {
			$parsed['id_base'] = $matches[1];
			$parsed['number']  = (int) $matches[2];
		} else {
			// Likely an old single widget.
			$parsed['id_base'] = $widget_id;
		}
		return $parsed;
	}

	/**
	 * Converts a widget setting ID (option path) to its id_base and number components.
	 *
	 * @since 3.9.0
	 *
	 * @param string $setting_id Widget setting ID.
	 * @return array|WP_Error Array containing a widget's id_base and number components,
	 *                        or a WP_Error object.
	 */
	public function parse_widget_setting_id( $setting_id ) {
		if ( ! preg_match( '/^(widget_(.+?))(?:\[(\d+)\])?$/', $setting_id, $matches ) ) {
			return new WP_Error( 'widget_setting_invalid_id' );
		}

		$id_base = $matches[2];
		$number  = isset( $matches[3] ) ? (int) $matches[3] : null;

		return compact( 'id_base', 'number' );
	}

	/**
	 * Calls admin_print_styles-widgets.php and admin_print_styles hooks to
	 * allow custom styles from plugins.
	 *
	 * @since 3.9.0
	 */
	public function print_styles() {
		/** This action is documented in wp-admin/admin-header.php */
		do_action( 'admin_print_styles-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/admin-header.php */
		do_action( 'admin_print_styles' );
	}

	/**
	 * Calls admin_print_scripts-widgets.php and admin_print_scripts hooks to
	 * allow custom scripts from plugins.
	 *
	 * @since 3.9.0
	 */
	public function print_scripts() {
		/** This action is documented in wp-admin/admin-header.php */
		do_action( 'admin_print_scripts-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/admin-header.php */
		do_action( 'admin_print_scripts' );
	}

	/**
	 * Enqueues scripts and styles for Customizer panel and export data to JavaScript.
	 *
	 * @since 3.9.0
	 *
	 * @global WP_Scripts $wp_scripts
	 * @global array $wp_registered_sidebars
	 * @global array $wp_registered_widgets
	 */
	public function enqueue_scripts() {
		global $wp_scripts, $wp_registered_sidebars, $wp_registered_widgets;

		wp_enqueue_style( 'customize-widgets' );
		wp_enqueue_script( 'customize-widgets' );

		/** This action is documented in wp-admin/admin-header.php */
		do_action( 'admin_enqueue_scripts', 'widgets.php' );

		/*
		 * Export available widgets with control_tpl removed from model
		 * since plugins need templates to be in the DOM.
		 */
		$available_widgets = array();

		foreach ( $this->get_available_widgets() as $available_widget ) {
			unset( $available_widget['control_tpl'] );
			$available_widgets[] = $available_widget;
		}

		$widget_reorder_nav_tpl = sprintf(
			'<div class="widget-reorder-nav"><span class="move-widget" tabindex="0">%1$s</span><span class="move-widget-down" tabindex="0">%2$s</span><span class="move-widget-up" tabindex="0">%3$s</span></div>',
			__( 'Move to another area&hellip;' ),
			__( 'Move down' ),
			__( 'Move up' )
		);

		$move_widget_area_tpl = str_replace(
			array( '{description}', '{btn}' ),
			array(
				__( 'Select an area to move this widget into:' ),
				_x( 'Move', 'Move widget' ),
			),
			'<div class="move-widget-area">
				<p class="description">{description}</p>
				<ul class="widget-area-select">
					<% _.each( sidebars, function ( sidebar ){ %>
						<li class="" data-id="<%- sidebar.id %>" title="<%- sidebar.description %>" tabindex="0"><%- sidebar.name %></li>
					<% }); %>
				</ul>
				<div class="move-widget-actions">
					<button class="move-widget-btn button" type="button">{btn}</button>
				</div>
			</div>'
		);

		/*
		 * Gather all strings in PHP that may be needed by JS on the client.
		 * Once JS i18n is implemented (in #20491), this can be removed.
		 */
		$some_non_rendered_areas_messages    = array();
		$some_non_rendered_areas_messages[1] = html_entity_decode(
			__( 'Your theme has 1 other widget area, but this particular page does not display it.' ),
			ENT_QUOTES,
			get_bloginfo( 'charset' )
		);
		$registered_sidebar_count            = count( $wp_registered_sidebars );
		for ( $non_rendered_count = 2; $non_rendered_count < $registered_sidebar_count; $non_rendered_count++ ) {
			$some_non_rendered_areas_messages[ $non_rendered_count ] = html_entity_decode(
				sprintf(
					/* translators: %s: The number of other widget areas registered but not rendered. */
					_n(
						'Your theme has %s other widget area, but this particular page does not display it.',
						'Your theme has %s other widget areas, but this particular page does not display them.',
						$non_rendered_count
					),
					number_format_i18n( $non_rendered_count )
				),
				ENT_QUOTES,
				get_bloginfo( 'charset' )
			);
		}

		if ( 1 === $registered_sidebar_count ) {
			$no_areas_shown_message = html_entity_decode(
				sprintf(
					__( 'Your theme has 1 widget area, but this particular page does not display it.' )
				),
				ENT_QUOTES,
				get_bloginfo( 'charset' )
			);
		} else {
			$no_areas_shown_message = html_entity_decode(
				sprintf(
					/* translators: %s: The total number of widget areas registered. */
					_n(
						'Your theme has %s widget area, but this particular page does not display it.',
						'Your theme has %s widget areas, but this particular page does not display them.',
						$registered_sidebar_count
					),
					number_format_i18n( $registered_sidebar_count )
				),
				ENT_QUOTES,
				get_bloginfo( 'charset' )
			);
		}

		$settings = array(
			'registeredSidebars'          => array_values( $wp_registered_sidebars ),
			'registeredWidgets'           => $wp_registered_widgets,
			'availableWidgets'            => $available_widgets, // @todo Merge this with registered_widgets.
			'l10n'                        => array(
				'saveBtnLabel'     => __( 'Apply' ),
				'saveBtnTooltip'   => __( 'Save and preview changes before publishing them.' ),
				'removeBtnLabel'   => __( 'Remove' ),
				'removeBtnTooltip' => __( 'Keep widget settings and move it to the inactive widgets' ),
				'error'            => __( 'An error has occurred. Please reload the page and try again.' ),
				'widgetMovedUp'    => __( 'Widget moved up' ),
				'widgetMovedDown'  => __( 'Widget moved down' ),
				'navigatePreview'  => __( 'You can navigate to other pages on your site while using the Customizer to view and edit the widgets displayed on those pages.' ),
				'someAreasShown'   => $some_non_rendered_areas_messages,
				'noAreasShown'     => $no_areas_shown_message,
				'reorderModeOn'    => __( 'Reorder mode enabled' ),
				'reorderModeOff'   => __( 'Reorder mode closed' ),
				'reorderLabelOn'   => esc_attr__( 'Reorder widgets' ),
				/* translators: %d: The number of widgets found. */
				'widgetsFound'     => __( 'Number of widgets found: %d' ),
				'noWidgetsFound'   => __( 'No widgets found.' ),
			),
			'tpl'                         => array(
				'widgetReorderNav' => $widget_reorder_nav_tpl,
				'moveWidgetArea'   => $move_widget_area_tpl,
			),
			'selectiveRefreshableWidgets' => $this->get_selective_refreshable_widgets(),
		);

		foreach ( $settings['registeredWidgets'] as &$registered_widget ) {
			unset( $registered_widget['callback'] ); // May not be JSON-serializeable.
		}

		$wp_scripts->add_data(
			'customize-widgets',
			'data',
			sprintf( 'var _wpCustomizeWidgetsSettings = %s;', wp_json_encode( $settings ) )
		);

		/*
		 * TODO: Update 'wp-customize-widgets' to not rely so much on things in
		 * 'customize-widgets'. This will let us skip most of the above and not
		 * enqueue 'customize-widgets' which saves bytes.
		 */

		if ( wp_use_widgets_block_editor() ) {
			$block_editor_context = new WP_Block_Editor_Context(
				array(
					'name' => 'core/customize-widgets',
				)
			);

			$editor_settings = get_block_editor_settings(
				get_legacy_widget_block_editor_settings(),
				$block_editor_context
			);

			wp_add_inline_script(
				'wp-customize-widgets',
				sprintf(
					'wp.domReady( function() {
					   wp.customizeWidgets.initialize( "widgets-customizer", %s );
					} );',
					wp_json_encode( $editor_settings )
				)
			);

			// Preload server-registered block schemas.
			wp_add_inline_script(
				'wp-blocks',
				'wp.blocks.unstable__bootstrapServerSideBlockDefinitions(' . wp_json_encode( get_block_editor_server_block_settings() ) . ');'
			);

			wp_add_inline_script(
				'wp-blocks',
				sprintf( 'wp.blocks.setCategories( %s );', wp_json_encode( get_block_categories( $block_editor_context ) ) ),
				'after'
			);

			wp_enqueue_script( 'wp-customize-widgets' );
			wp_enqueue_style( 'wp-customize-widgets' );

			/** This action is documented in edit-form-blocks.php */
			do_action( 'enqueue_block_editor_assets' );
		}
	}

	/**
	 * Renders the widget form control templates into the DOM.
	 *
	 * @since 3.9.0
	 */
	public function output_widget_control_templates() {
		?>
		<div id="widgets-left"><!-- compatibility with JS which looks for widget templates here -->
		<div id="available-widgets">
			<div class="customize-section-title">
				<button class="customize-section-back" tabindex="-1">
					<span class="screen-reader-text"><?php _e( 'Back' ); ?></span>
				</button>
				<h3>
					<span class="customize-action">
					<?php
						/* translators: &#9656; is the unicode right-pointing triangle. %s: Section title in the Customizer. */
						printf( __( 'Customizing &#9656; %s' ), esc_html( $this->manager->get_panel( 'widgets' )->title ) );
					?>
					</span>
					<?php _e( 'Add a Widget' ); ?>
				</h3>
			</div>
			<div id="available-widgets-filter">
				<label class="screen-reader-text" for="widgets-search"><?php _e( 'Search Widgets' ); ?></label>
				<input type="text" id="widgets-search" placeholder="<?php esc_attr_e( 'Search widgets&hellip;' ); ?>" aria-describedby="widgets-search-desc" />
				<div class="search-icon" aria-hidden="true"></div>
				<button type="button" class="clear-results"><span class="screen-reader-text"><?php _e( 'Clear Results' ); ?></span></button>
				<p class="screen-reader-text" id="widgets-search-desc"><?php _e( 'The search results will be updated as you type.' ); ?></p>
			</div>
			<div id="available-widgets-list">
			<?php foreach ( $this->get_available_widgets() as $available_widget ) : ?>
				<div id="widget-tpl-<?php echo esc_attr( $available_widget['id'] ); ?>" data-widget-id="<?php echo esc_attr( $available_widget['id'] ); ?>" class="widget-tpl <?php echo esc_attr( $available_widget['id'] ); ?>" tabindex="0">
					<?php echo $available_widget['control_tpl']; ?>
				</div>
			<?php endforeach; ?>
			<p class="no-widgets-found-message"><?php _e( 'No widgets found.' ); ?></p>
			</div><!-- #available-widgets-list -->
		</div><!-- #available-widgets -->
		</div><!-- #widgets-left -->
		<?php
	}

	/**
	 * Calls admin_print_footer_scripts and admin_print_scripts hooks to
	 * allow custom scripts from plugins.
	 *
	 * @since 3.9.0
	 */
	public function print_footer_scripts() {
		/** This action is documented in wp-admin/admin-footer.php */
		do_action( 'admin_print_footer_scripts-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/admin-footer.php */
		do_action( 'admin_print_footer_scripts' );

		/** This action is documented in wp-admin/admin-footer.php */
		do_action( 'admin_footer-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores
	}

	/**
	 * Retrieves common arguments to supply when constructing a Customizer setting.
	 *
	 * @since 3.9.0
	 *
	 * @param string $id        Widget setting ID.
	 * @param array  $overrides Array of setting overrides.
	 * @return array Possibly modified setting arguments.
	 */
	public function get_setting_args( $id, $overrides = array() ) {
		$args = array(
			'type'       => 'option',
			'capability' => 'edit_theme_options',
			'default'    => array(),
		);

		if ( preg_match( $this->setting_id_patterns['sidebar_widgets'], $id, $matches ) ) {
			$args['sanitize_callback']    = array( $this, 'sanitize_sidebar_widgets' );
			$args['sanitize_js_callback'] = array( $this, 'sanitize_sidebar_widgets_js_instance' );
			$args['transport']            = current_theme_supports( 'customize-selective-refresh-widgets' ) ? 'postMessage' : 'refresh';
		} elseif ( preg_match( $this->setting_id_patterns['widget_instance'], $id, $matches ) ) {
			$id_base                      = $matches['id_base'];
			$args['sanitize_callback']    = function( $value ) use ( $id_base ) {
				return $this->sanitize_widget_instance( $value, $id_base );
			};
			$args['sanitize_js_callback'] = function( $value ) use ( $id_base ) {
				return $this->sanitize_widget_js_instance( $value, $id_base );
			};
			$args['transport']            = $this->is_widget_selective_refreshable( $matches['id_base'] ) ? 'postMessage' : 'refresh';
		}

		$args = array_merge( $args, $overrides );

		/**
		 * Filters the common arguments supplied when constructing a Customizer setting.
		 *
		 * @since 3.9.0
		 *
		 * @see WP_Customize_Setting
		 *
		 * @param array  $args Array of Customizer setting arguments.
		 * @param string $id   Widget setting ID.
		 */
		return apply_filters( 'widget_customizer_setting_args', $args, $id );
	}

	/**
	 * Ensures sidebar widget arrays only ever contain widget IDS.
	 *
	 * Used as the 'sanitize_callback' for each $sidebars_widgets setting.
	 *
	 * @since 3.9.0
	 *
	 * @param string[] $widget_ids Array of widget IDs.
	 * @return string[] Array of sanitized widget IDs.
	 */
	public function sanitize_sidebar_widgets( $widget_ids ) {
		$widget_ids           = array_map( 'strval', (array) $widget_ids );
		$sanitized_widget_ids = array();
		foreach ( $widget_ids as $widget_id ) {
			$sanitized_widget_ids[] = preg_replace( '/[^a-z0-9_\-]/', '', $widget_id );
		}
		return $sanitized_widget_ids;
	}

	/**
	 * Builds up an index of all available widgets for use in Backbone models.
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_widgets
	 * @global array $wp_registered_widget_controls
	 *
	 * @see wp_list_widgets()
	 *
	 * @return array List of available widgets.
	 */
	public function get_available_widgets() {
		static $available_widgets = array();
		if ( ! empty( $available_widgets ) ) {
			return $available_widgets;
		}

		global $wp_registered_widgets, $wp_registered_widget_controls;
		require_once ABSPATH . 'wp-admin/includes/widgets.php'; // For next_widget_id_number().

		$sort = $wp_registered_widgets;
		usort( $sort, array( $this, '_sort_name_callback' ) );
		$done = array();

		foreach ( $sort as $widget ) {
			if ( in_array( $widget['callback'], $done, true ) ) { // We already showed this multi-widget.
				continue;
			}

			$sidebar = is_active_widget( $widget['callback'], $widget['id'], false, false );
			$done[]  = $widget['callback'];

			if ( ! isset( $widget['params'][0] ) ) {
				$widget['params'][0] = array();
			}

			$available_widget = $widget;
			unset( $available_widget['callback'] ); // Not serializable to JSON.

			$args = array(
				'widget_id'   => $widget['id'],
				'widget_name' => $widget['name'],
				'_display'    => 'template',
			);

			$is_disabled     = false;
			$is_multi_widget = ( isset( $wp_registered_widget_controls[ $widget['id'] ]['id_base'] ) && isset( $widget['params'][0]['number'] ) );
			if ( $is_multi_widget ) {
				$id_base            = $wp_registered_widget_controls[ $widget['id'] ]['id_base'];
				$args['_temp_id']   = "$id_base-__i__";
				$args['_multi_num'] = next_widget_id_number( $id_base );
				$args['_add']       = 'multi';
			} else {
				$args['_add'] = 'single';

				if ( $sidebar && 'wp_inactive_widgets' !== $sidebar ) {
					$is_disabled = true;
				}
				$id_base = $widget['id'];
			}

			$list_widget_controls_args = wp_list_widget_controls_dynamic_sidebar(
				array(
					0 => $args,
					1 => $widget['params'][0],
				)
			);
			$control_tpl               = $this->get_widget_control( $list_widget_controls_args );

			// The properties here are mapped to the Backbone Widget model.
			$available_widget = array_merge(
				$available_widget,
				array(
					'temp_id'      => isset( $args['_temp_id'] ) ? $args['_temp_id'] : null,
					'is_multi'     => $is_multi_widget,
					'control_tpl'  => $control_tpl,
					'multi_number' => ( 'multi' === $args['_add'] ) ? $args['_multi_num'] : false,
					'is_disabled'  => $is_disabled,
					'id_base'      => $id_base,
					'transport'    => $this->is_widget_selective_refreshable( $id_base ) ? 'postMessage' : 'refresh',
					'width'        => $wp_registered_widget_controls[ $widget['id'] ]['width'],
					'height'       => $wp_registered_widget_controls[ $widget['id'] ]['height'],
					'is_wide'      => $this->is_wide_widget( $widget['id'] ),
				)
			);

			$available_widgets[] = $available_widget;
		}

		return $available_widgets;
	}

	/**
	 * Naturally orders available widgets by name.
	 *
	 * @since 3.9.0
	 *
	 * @param array $widget_a The first widget to compare.
	 * @param array $widget_b The second widget to compare.
	 * @return int Reorder position for the current widget comparison.
	 */
	protected function _sort_name_callback( $widget_a, $widget_b ) {
		return strnatcasecmp( $widget_a['name'], $widget_b['name'] );
	}

	/**
	 * Retrieves the widget control markup.
	 *
	 * @since 3.9.0
	 *
	 * @param array $args Widget control arguments.
	 * @return string Widget control form HTML markup.
	 */
	public function get_widget_control( $args ) {
		$args[0]['before_form']           = '<div class="form">';
		$args[0]['after_form']            = '</div><!-- .form -->';
		$args[0]['before_widget_content'] = '<div class="widget-content">';
		$args[0]['after_widget_content']  = '</div><!-- .widget-content -->';
		ob_start();
		wp_widget_control( ...$args );
		$control_tpl = ob_get_clean();
		return $control_tpl;
	}

	/**
	 * Retrieves the widget control markup parts.
	 *
	 * @since 4.4.0
	 *
	 * @param array $args Widget control arguments.
	 * @return array {
	 *     @type string $control Markup for widget control wrapping form.
	 *     @type string $content The contents of the widget form itself.
	 * }
	 */
	public function get_widget_control_parts( $args ) {
		$args[0]['before_widget_content'] = '<div class="widget-content">';
		$args[0]['after_widget_content']  = '</div><!-- .widget-content -->';
		$control_markup                   = $this->get_widget_control( $args );

		$content_start_pos = strpos( $control_markup, $args[0]['before_widget_content'] );
		$content_end_pos   = strrpos( $control_markup, $args[0]['after_widget_content'] );

		$control  = substr( $control_markup, 0, $content_start_pos + strlen( $args[0]['before_widget_content'] ) );
		$control .= substr( $control_markup, $content_end_pos );
		$content  = trim(
			substr(
				$control_markup,
				$content_start_pos + strlen( $args[0]['before_widget_content'] ),
				$content_end_pos - $content_start_pos - strlen( $args[0]['before_widget_content'] )
			)
		);

		return compact( 'control', 'content' );
	}

	/**
	 * Adds hooks for the Customizer preview.
	 *
	 * @since 3.9.0
	 */
	public function customize_preview_init() {
		add_action( 'wp_enqueue_scripts', array( $this, 'customize_preview_enqueue' ) );
		add_action( 'wp_print_styles', array( $this, 'print_preview_css' ), 1 );
		add_action( 'wp_footer', array( $this, 'export_preview_data' ), 20 );
	}

	/**
	 * Refreshes the nonce for widget updates.
	 *
	 * @since 4.2.0
	 *
	 * @param array $nonces Array of nonces.
	 * @return array Array of nonces.
	 */
	public function refresh_nonces( $nonces ) {
		$nonces['update-widget'] = wp_create_nonce( 'update-widget' );
		return $nonces;
	}

	/**
	 * Tells the script loader to load the scripts and styles of custom blocks
	 * if the widgets block editor is enabled.
	 *
	 * @since 5.8.0
	 *
	 * @param bool $is_block_editor_screen Current decision about loading block assets.
	 * @return bool Filtered decision about loading block assets.
	 */
	public function should_load_block_editor_scripts_and_styles( $is_block_editor_screen ) {
		if ( wp_use_widgets_block_editor() ) {
			return true;
		}

		return $is_block_editor_screen;
	}

	/**
	 * When previewing, ensures the proper previewing widgets are used.
	 *
	 * Because wp_get_sidebars_widgets() gets called early at {@see 'init' } (via
	 * wp_convert_widget_settings()) and can set global variable `$_wp_sidebars_widgets`
	 * to the value of `get_option( 'sidebars_widgets' )` before the Customizer preview
	 * filter is added, it has to be reset after the filter has been added.
	 *
	 * @since 3.9.0
	 *
	 * @param array $sidebars_widgets List of widgets for the current sidebar.
	 * @return array
	 */
	public function preview_sidebars_widgets( $sidebars_widgets ) {
		$sidebars_widgets = get_option( 'sidebars_widgets', array() );

		unset( $sidebars_widgets['array_version'] );
		return $sidebars_widgets;
	}

	/**
	 * Enqueues scripts for the Customizer preview.
	 *
	 * @since 3.9.0
	 */
	public function customize_preview_enqueue() {
		wp_enqueue_script( 'customize-preview-widgets' );
	}

	/**
	 * Inserts default style for highlighted widget at early point so theme
	 * stylesheet can override.
	 *
	 * @since 3.9.0
	 */
	public function print_preview_css() {
		?>
		<style>
		.widget-customizer-highlighted-widget {
			outline: none;
			-webkit-box-shadow: 0 0 2px rgba(30, 140, 190, 0.8);
			box-shadow: 0 0 2px rgba(30, 140, 190, 0.8);
			position: relative;
			z-index: 1;
		}
		</style>
		<?php
	}

	/**
	 * Communicates the sidebars that appeared on the page at the very end of the page,
	 * and at the very end of the wp_footer,
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_sidebars
	 * @global array $wp_registered_widgets
	 */
	public function export_preview_data() {
		global $wp_registered_sidebars, $wp_registered_widgets;

		$switched_locale = switch_to_locale( get_user_locale() );

		$l10n = array(
			'widgetTooltip' => __( 'Shift-click to edit this widget.' ),
		);

		if ( $switched_locale ) {
			restore_previous_locale();
		}

		$rendered_sidebars = array_filter( $this->rendered_sidebars );
		$rendered_widgets  = array_filter( $this->rendered_widgets );

		// Prepare Customizer settings to pass to JavaScript.
		$settings = array(
			'renderedSidebars'            => array_fill_keys( array_keys( $rendered_sidebars ), true ),
			'renderedWidgets'             => array_fill_keys( array_keys( $rendered_widgets ), true ),
			'registeredSidebars'          => array_values( $wp_registered_sidebars ),
			'registeredWidgets'           => $wp_registered_widgets,
			'l10n'                        => $l10n,
			'selectiveRefreshableWidgets' => $this->get_selective_refreshable_widgets(),
		);

		foreach ( $settings['registeredWidgets'] as &$registered_widget ) {
			unset( $registered_widget['callback'] ); // May not be JSON-serializeable.
		}

		?>
		<script type="text/javascript">
			var _wpWidgetCustomizerPreviewSettings = <?php echo wp_json_encode( $settings ); ?>;
		</script>
		<?php
	}

	/**
	 * Tracks the widgets that were rendered.
	 *
	 * @since 3.9.0
	 *
	 * @param array $widget Rendered widget to tally.
	 */
	public function tally_rendered_widgets( $widget ) {
		$this->rendered_widgets[ $widget['id'] ] = true;
	}

	/**
	 * Determine if a widget is rendered on the page.
	 *
	 * @since 4.0.0
	 *
	 * @param string $widget_id Widget ID to check.
	 * @return bool Whether the widget is rendered.
	 */
	public function is_widget_rendered( $widget_id ) {
		return ! empty( $this->rendered_widgets[ $widget_id ] );
	}

	/**
	 * Determines if a sidebar is rendered on the page.
	 *
	 * @since 4.0.0
	 *
	 * @param string $sidebar_id Sidebar ID to check.
	 * @return bool Whether the sidebar is rendered.
	 */
	public function is_sidebar_rendered( $sidebar_id ) {
		return ! empty( $this->rendered_sidebars[ $sidebar_id ] );
	}

	/**
	 * Tallies the sidebars rendered via is_active_sidebar().
	 *
	 * Keep track of the times that is_active_sidebar() is called in the template,
	 * and assume that this means that the sidebar would be rendered on the template
	 * if there were widgets populating it.
	 *
	 * @since 3.9.0
	 *
	 * @param bool   $is_active  Whether the sidebar is active.
	 * @param string $sidebar_id Sidebar ID.
	 * @return bool Whether the sidebar is active.
	 */
	public function tally_sidebars_via_is_active_sidebar_calls( $is_active, $sidebar_id ) {
		if ( is_registered_sidebar( $sidebar_id ) ) {
			$this->rendered_sidebars[ $sidebar_id ] = true;
		}

		/*
		 * We may need to force this to true, and also force-true the value
		 * for 'dynamic_sidebar_has_widgets' if we want to ensure that there
		 * is an area to drop widgets into, if the sidebar is empty.
		 */
		return $is_active;
	}

	/**
	 * Tallies the sidebars rendered via dynamic_sidebar().
	 *
	 * Keep track of the times that dynamic_sidebar() is called in the template,
	 * and assume this means the sidebar would be rendered on the template if
	 * there were widgets populating it.
	 *
	 * @since 3.9.0
	 *
	 * @param bool   $has_widgets Whether the current sidebar has widgets.
	 * @param string $sidebar_id  Sidebar ID.
	 * @return bool Whether the current sidebar has widgets.
	 */
	public function tally_sidebars_via_dynamic_sidebar_calls( $has_widgets, $sidebar_id ) {
		if ( is_registered_sidebar( $sidebar_id ) ) {
			$this->rendered_sidebars[ $sidebar_id ] = true;
		}

		/*
		 * We may need to force this to true, and also force-true the value
		 * for 'is_active_sidebar' if we want to ensure there is an area to
		 * drop widgets into, if the sidebar is empty.
		 */
		return $has_widgets;
	}

	/**
	 * Retrieves MAC for a serialized widget instance string.
	 *
	 * Allows values posted back from JS to be rejected if any tampering of the
	 * data has occurred.
	 *
	 * @since 3.9.0
	 *
	 * @param string $serialized_instance Widget instance.
	 * @return string MAC for serialized widget instance.
	 */
	protected function get_instance_hash_key( $serialized_instance ) {
		return wp_hash( $serialized_instance );
	}

	/**
	 * Sanitizes a widget instance.
	 *
	 * Unserialize the JS-instance for storing in the options. It's important that this filter
	 * only get applied to an instance *once*.
	 *
	 * @since 3.9.0
	 * @since 5.8.0 Added the `$id_base` parameter.
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 *
	 * @param array  $value   Widget instance to sanitize.
	 * @param string $id_base Optional. Base of the ID of the widget being sanitized. Default null.
	 * @return array|void Sanitized widget instance.
	 */
	public function sanitize_widget_instance( $value, $id_base = null ) {
		global $wp_widget_factory;

		if ( array() === $value ) {
			return $value;
		}

		if ( isset( $value['raw_instance'] ) && $id_base && wp_use_widgets_block_editor() ) {
			$widget_object = $wp_widget_factory->get_widget_object( $id_base );
			if ( ! empty( $widget_object->widget_options['show_instance_in_rest'] ) ) {
				if ( 'block' === $id_base && ! current_user_can( 'unfiltered_html' ) ) {
					/*
					 * The content of the 'block' widget is not filtered on the fly while editing.
					 * Filter the content here to prevent vulnerabilities.
					 */
					$value['raw_instance']['content'] = wp_kses_post( $value['raw_instance']['content'] );
				}

				return $value['raw_instance'];
			}
		}

		if (
			empty( $value['is_widget_customizer_js_value'] ) ||
			empty( $value['instance_hash_key'] ) ||
			empty( $value['encoded_serialized_instance'] )
		) {
			return;
		}

		$decoded = base64_decode( $value['encoded_serialized_instance'], true );
		if ( false === $decoded ) {
			return;
		}

		if ( ! hash_equals( $this->get_instance_hash_key( $decoded ), $value['instance_hash_key'] ) ) {
			return;
		}

		$instance = unserialize( $decoded );
		if ( false === $instance ) {
			return;
		}

		return $instance;
	}

	/**
	 * Converts a widget instance into JSON-representable format.
	 *
	 * @since 3.9.0
	 * @since 5.8.0 Added the `$id_base` parameter.
	 *
	 * @global WP_Widget_Factory $wp_widget_factory
	 *
	 * @param array  $value   Widget instance to convert to JSON.
	 * @param string $id_base Optional. Base of the ID of the widget being sanitized. Default null.
	 * @return array JSON-converted widget instance.
	 */
	public function sanitize_widget_js_instance( $value, $id_base = null ) {
		global $wp_widget_factory;

		if ( empty( $value['is_widget_customizer_js_value'] ) ) {
			$serialized = serialize( $value );

			$js_value = array(
				'encoded_serialized_instance'   => base64_encode( $serialized ),
				'title'                         => empty( $value['title'] ) ? '' : $value['title'],
				'is_widget_customizer_js_value' => true,
				'instance_hash_key'             => $this->get_instance_hash_key( $serialized ),
			);

			if ( $id_base && wp_use_widgets_block_editor() ) {
				$widget_object = $wp_widget_factory->get_widget_object( $id_base );
				if ( ! empty( $widget_object->widget_options['show_instance_in_rest'] ) ) {
					$js_value['raw_instance'] = (object) $value;
				}
			}

			return $js_value;
		}

		return $value;
	}

	/**
	 * Strips out widget IDs for widgets which are no longer registered.
	 *
	 * One example where this might happen is when a plugin orphans a widget
	 * in a sidebar upon deactivation.
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_widgets
	 *
	 * @param array $widget_ids List of widget IDs.
	 * @return array Parsed list of widget IDs.
	 */
	public function sanitize_sidebar_widgets_js_instance( $widget_ids ) {
		global $wp_registered_widgets;
		$widget_ids = array_values( array_intersect( $widget_ids, array_keys( $wp_registered_widgets ) ) );
		return $widget_ids;
	}

	/**
	 * Finds and invokes the widget update and control callbacks.
	 *
	 * Requires that `$_POST` be populated with the instance data.
	 *
	 * @since 3.9.0
	 *
	 * @global array $wp_registered_widget_updates
	 * @global array $wp_registered_widget_controls
	 *
	 * @param string $widget_id Widget ID.
	 * @return array|WP_Error Array containing the updated widget information.
	 *                        A WP_Error object, otherwise.
	 */
	public function call_widget_update( $widget_id ) {
		global $wp_registered_widget_updates, $wp_registered_widget_controls;

		$setting_id = $this->get_setting_id( $widget_id );

		/*
		 * Make sure that other setting changes have previewed since this widget
		 * may depend on them (e.g. Menus being present for Navigation Menu widget).
		 */
		if ( ! did_action( 'customize_preview_init' ) ) {
			foreach ( $this->manager->settings() as $setting ) {
				if ( $setting->id !== $setting_id ) {
					$setting->preview();
				}
			}
		}

		$this->start_capturing_option_updates();
		$parsed_id   = $this->parse_widget_id( $widget_id );
		$option_name = 'widget_' . $parsed_id['id_base'];

		/*
		 * If a previously-sanitized instance is provided, populate the input vars
		 * with its values so that the widget update callback will read this instance
		 */
		$added_input_vars = array();
		if ( ! empty( $_POST['sanitized_widget_setting'] ) ) {
			$sanitized_widget_setting = json_decode( $this->get_post_value( 'sanitized_widget_setting' ), true );
			if ( false === $sanitized_widget_setting ) {
				$this->stop_capturing_option_updates();
				return new WP_Error( 'widget_setting_malformed' );
			}

			$instance = $this->sanitize_widget_instance( $sanitized_widget_setting, $parsed_id['id_base'] );
			if ( is_null( $instance ) ) {
				$this->stop_capturing_option_updates();
				return new WP_Error( 'widget_setting_unsanitized' );
			}

			if ( ! is_null( $parsed_id['number'] ) ) {
				$value                         = array();
				$value[ $parsed_id['number'] ] = $instance;
				$key                           = 'widget-' . $parsed_id['id_base'];
				$_REQUEST[ $key ]              = wp_slash( $value );
				$_POST[ $key ]                 = $_REQUEST[ $key ];
				$added_input_vars[]            = $key;
			} else {
				foreach ( $instance as $key => $value ) {
					$_REQUEST[ $key ]   = wp_slash( $value );
					$_POST[ $key ]      = $_REQUEST[ $key ];
					$added_input_vars[] = $key;
				}
			}
		}

		// Invoke the widget update callback.
		foreach ( (array) $wp_registered_widget_updates as $name => $control ) {
			if ( $name === $parsed_id['id_base'] && is_callable( $control['callback'] ) ) {
				ob_start();
				call_user_func_array( $control['callback'], $control['params'] );
				ob_end_clean();
				break;
			}
		}

		// Clean up any input vars that were manually added.
		foreach ( $added_input_vars as $key ) {
			unset( $_POST[ $key ] );
			unset( $_REQUEST[ $key ] );
		}

		// Make sure the expected option was updated.
		if ( 0 !== $this->count_captured_options() ) {
			if ( $this->count_captured_options() > 1 ) {
				$this->stop_capturing_option_updates();
				return new WP_Error( 'widget_setting_too_many_options' );
			}

			$updated_option_name = key( $this->get_captured_options() );
			if ( $updated_option_name !== $option_name ) {
				$this->stop_capturing_option_updates();
				return new WP_Error( 'widget_setting_unexpected_option' );
			}
		}

		// Obtain the widget instance.
		$option = $this->get_captured_option( $option_name );
		if ( null !== $parsed_id['number'] ) {
			$instance = $option[ $parsed_id['number'] ];
		} else {
			$instance = $option;
		}

		/*
		 * Override the incoming $_POST['customized'] for a newly-created widget's
		 * setting with the new $instance so that the preview filter currently
		 * in place from WP_Customize_Setting::preview() will use this value
		 * instead of the default widget instance value (an empty array).
		 */
		$this->manager->set_post_value( $setting_id, $this->sanitize_widget_js_instance( $instance, $parsed_id['id_base'] ) );

		// Obtain the widget control with the updated instance in place.
		ob_start();
		$form = $wp_registered_widget_controls[ $widget_id ];
		if ( $form ) {
			call_user_func_array( $form['callback'], $form['params'] );
		}
		$form = ob_get_clean();

		$this->stop_capturing_option_updates();

		return compact( 'instance', 'form' );
	}

	/**
	 * Updates widget settings asynchronously.
	 *
	 * Allows the Customizer to update a widget using its form, but return the new
	 * instance info via Ajax instead of saving it to the options table.
	 *
	 * Most code here copied from wp_ajax_save_widget().
	 *
	 * @since 3.9.0
	 *
	 * @see wp_ajax_save_widget()
	 */
	public function wp_ajax_update_widget() {

		if ( ! is_user_logged_in() ) {
			wp_die( 0 );
		}

		check_ajax_referer( 'update-widget', 'nonce' );

		if ( ! current_user_can( 'edit_theme_options' ) ) {
			wp_die( -1 );
		}

		if ( empty( $_POST['widget-id'] ) ) {
			wp_send_json_error( 'missing_widget-id' );
		}

		/** This action is documented in wp-admin/includes/ajax-actions.php */
		do_action( 'load-widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/includes/ajax-actions.php */
		do_action( 'widgets.php' ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		/** This action is documented in wp-admin/widgets.php */
		do_action( 'sidebar_admin_setup' );

		$widget_id = $this->get_post_value( 'widget-id' );
		$parsed_id = $this->parse_widget_id( $widget_id );
		$id_base   = $parsed_id['id_base'];

		$is_updating_widget_template = (
			isset( $_POST[ 'widget-' . $id_base ] )
			&&
			is_array( $_POST[ 'widget-' . $id_base ] )
			&&
			preg_match( '/__i__|%i%/', key( $_POST[ 'widget-' . $id_base ] ) )
		);
		if ( $is_updating_widget_template ) {
			wp_send_json_error( 'template_widget_not_updatable' );
		}

		$updated_widget = $this->call_widget_update( $widget_id ); // => {instance,form}
		if ( is_wp_error( $updated_widget ) ) {
			wp_send_json_error( $updated_widget->get_error_code() );
		}

		$form     = $updated_widget['form'];
		$instance = $this->sanitize_widget_js_instance( $updated_widget['instance'], $id_base );

		wp_send_json_success( compact( 'form', 'instance' ) );
	}

	/*
	 * Selective Refresh Methods
	 */

	/**
	 * Filters arguments for dynamic widget partials.
	 *
	 * @since 4.5.0
	 *
	 * @param array|false $partial_args Partial arguments.
	 * @param string      $partial_id   Partial ID.
	 * @return array (Maybe) modified partial arguments.
	 */
	public function customize_dynamic_partial_args( $partial_args, $partial_id ) {
		if ( ! current_theme_supports( 'customize-selective-refresh-widgets' ) ) {
			return $partial_args;
		}

		if ( preg_match( '/^widget\[(?P<widget_id>.+)\]$/', $partial_id, $matches ) ) {
			if ( false === $partial_args ) {
				$partial_args = array();
			}
			$partial_args = array_merge(
				$partial_args,
				array(
					'type'                => 'widget',
					'render_callback'     => array( $this, 'render_widget_partial' ),
					'container_inclusive' => true,
					'settings'            => array( $this->get_setting_id( $matches['widget_id'] ) ),
					'capability'          => 'edit_theme_options',
				)
			);
		}

		return $partial_args;
	}

	/**
	 * Adds hooks for selective refresh.
	 *
	 * @since 4.5.0
	 */
	public function selective_refresh_init() {
		if ( ! current_theme_supports( 'customize-selective-refresh-widgets' ) ) {
			return;
		}
		add_filter( 'dynamic_sidebar_params', array( $this, 'filter_dynamic_sidebar_params' ) );
		add_filter( 'wp_kses_allowed_html', array( $this, 'filter_wp_kses_allowed_data_attributes' ) );
		add_action( 'dynamic_sidebar_before', array( $this, 'start_dynamic_sidebar' ) );
		add_action( 'dynamic_sidebar_after', array( $this, 'end_dynamic_sidebar' ) );
	}

	/**
	 * Inject selective refresh data attributes into widget container elements.
	 *
	 * @since 4.5.0
	 *
	 * @param array $params {
	 *     Dynamic sidebar params.
	 *
	 *     @type array $args        Sidebar args.
	 *     @type array $widget_args Widget args.
	 * }
	 * @see WP_Customize_Nav_Menus::filter_wp_nav_menu_args()
	 *
	 * @return array Params.
	 */
	public function filter_dynamic_sidebar_params( $params ) {
		$sidebar_args = array_merge(
			array(
				'before_widget' => '',
				'after_widget'  => '',
			),
			$params[0]
		);

		// Skip widgets not in a registered sidebar or ones which lack a proper wrapper element to attach the data-* attributes to.
		$matches  = array();
		$is_valid = (
			isset( $sidebar_args['id'] )
			&&
			is_registered_sidebar( $sidebar_args['id'] )
			&&
			( isset( $this->current_dynamic_sidebar_id_stack[0] ) && $this->current_dynamic_sidebar_id_stack[0] === $sidebar_args['id'] )
			&&
			preg_match( '#^<(?P<tag_name>\w+)#', $sidebar_args['before_widget'], $matches )
		);
		if ( ! $is_valid ) {
			return $params;
		}
		$this->before_widget_tags_seen[ $matches['tag_name'] ] = true;

		$context = array(
			'sidebar_id' => $sidebar_args['id'],
		);
		if ( isset( $this->context_sidebar_instance_number ) ) {
			$context['sidebar_instance_number'] = $this->context_sidebar_instance_number;
		} elseif ( isset( $sidebar_args['id'] ) && isset( $this->sidebar_instance_count[ $sidebar_args['id'] ] ) ) {
			$context['sidebar_instance_number'] = $this->sidebar_instance_count[ $sidebar_args['id'] ];
		}

		$attributes                    = sprintf( ' data-customize-partial-id="%s"', esc_attr( 'widget[' . $sidebar_args['widget_id'] . ']' ) );
		$attributes                   .= ' data-customize-partial-type="widget"';
		$attributes                   .= sprintf( ' data-customize-partial-placement-context="%s"', esc_attr( wp_json_encode( $context ) ) );
		$attributes                   .= sprintf( ' data-customize-widget-id="%s"', esc_attr( $sidebar_args['widget_id'] ) );
		$sidebar_args['before_widget'] = preg_replace( '#^(<\w+)#', '$1 ' . $attributes, $sidebar_args['before_widget'] );

		$params[0] = $sidebar_args;
		return $params;
	}

	/**
	 * List of the tag names seen for before_widget strings.
	 *
	 * This is used in the {@see 'filter_wp_kses_allowed_html'} filter to ensure that the
	 * data-* attributes can be allowed.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $before_widget_tags_seen = array();

	/**
	 * Ensures the HTML data-* attributes for selective refresh are allowed by kses.
	 *
	 * This is needed in case the `$before_widget` is run through wp_kses() when printed.
	 *
	 * @since 4.5.0
	 *
	 * @param array $allowed_html Allowed HTML.
	 * @return array (Maybe) modified allowed HTML.
	 */
	public function filter_wp_kses_allowed_data_attributes( $allowed_html ) {
		foreach ( array_keys( $this->before_widget_tags_seen ) as $tag_name ) {
			if ( ! isset( $allowed_html[ $tag_name ] ) ) {
				$allowed_html[ $tag_name ] = array();
			}
			$allowed_html[ $tag_name ] = array_merge(
				$allowed_html[ $tag_name ],
				array_fill_keys(
					array(
						'data-customize-partial-id',
						'data-customize-partial-type',
						'data-customize-partial-placement-context',
						'data-customize-partial-widget-id',
						'data-customize-partial-options',
					),
					true
				)
			);
		}
		return $allowed_html;
	}

	/**
	 * Keep track of the number of times that dynamic_sidebar() was called for a given sidebar index.
	 *
	 * This helps facilitate the uncommon scenario where a single sidebar is rendered multiple times on a template.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $sidebar_instance_count = array();

	/**
	 * The current request's sidebar_instance_number context.
	 *
	 * @since 4.5.0
	 * @var int|null
	 */
	protected $context_sidebar_instance_number;

	/**
	 * Current sidebar ID being rendered.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $current_dynamic_sidebar_id_stack = array();

	/**
	 * Begins keeping track of the current sidebar being rendered.
	 *
	 * Insert marker before widgets are rendered in a dynamic sidebar.
	 *
	 * @since 4.5.0
	 *
	 * @param int|string $index Index, name, or ID of the dynamic sidebar.
	 */
	public function start_dynamic_sidebar( $index ) {
		array_unshift( $this->current_dynamic_sidebar_id_stack, $index );
		if ( ! isset( $this->sidebar_instance_count[ $index ] ) ) {
			$this->sidebar_instance_count[ $index ] = 0;
		}
		$this->sidebar_instance_count[ $index ] += 1;
		if ( ! $this->manager->selective_refresh->is_render_partials_request() ) {
			printf( "\n<!--dynamic_sidebar_before:%s:%d-->\n", esc_html( $index ), (int) $this->sidebar_instance_count[ $index ] );
		}
	}

	/**
	 * Finishes keeping track of the current sidebar being rendered.
	 *
	 * Inserts a marker after widgets are rendered in a dynamic sidebar.
	 *
	 * @since 4.5.0
	 *
	 * @param int|string $index Index, name, or ID of the dynamic sidebar.
	 */
	public function end_dynamic_sidebar( $index ) {
		array_shift( $this->current_dynamic_sidebar_id_stack );
		if ( ! $this->manager->selective_refresh->is_render_partials_request() ) {
			printf( "\n<!--dynamic_sidebar_after:%s:%d-->\n", esc_html( $index ), (int) $this->sidebar_instance_count[ $index ] );
		}
	}

	/**
	 * Current sidebar being rendered.
	 *
	 * @since 4.5.0
	 * @var string|null
	 */
	protected $rendering_widget_id;

	/**
	 * Current widget being rendered.
	 *
	 * @since 4.5.0
	 * @var string|null
	 */
	protected $rendering_sidebar_id;

	/**
	 * Filters sidebars_widgets to ensure the currently-rendered widget is the only widget in the current sidebar.
	 *
	 * @since 4.5.0
	 *
	 * @param array $sidebars_widgets Sidebars widgets.
	 * @return array Filtered sidebars widgets.
	 */
	public function filter_sidebars_widgets_for_rendering_widget( $sidebars_widgets ) {
		$sidebars_widgets[ $this->rendering_sidebar_id ] = array( $this->rendering_widget_id );
		return $sidebars_widgets;
	}

	/**
	 * Renders a specific widget using the supplied sidebar arguments.
	 *
	 * @since 4.5.0
	 *
	 * @see dynamic_sidebar()
	 *
	 * @param WP_Customize_Partial $partial Partial.
	 * @param array                $context {
	 *     Sidebar args supplied as container context.
	 *
	 *     @type string $sidebar_id              ID for sidebar for widget to render into.
	 *     @type int    $sidebar_instance_number Disambiguating instance number.
	 * }
	 * @return string|false
	 */
	public function render_widget_partial( $partial, $context ) {
		$id_data   = $partial->id_data();
		$widget_id = array_shift( $id_data['keys'] );

		if ( ! is_array( $context )
			|| empty( $context['sidebar_id'] )
			|| ! is_registered_sidebar( $context['sidebar_id'] )
		) {
			return false;
		}

		$this->rendering_sidebar_id = $context['sidebar_id'];

		if ( isset( $context['sidebar_instance_number'] ) ) {
			$this->context_sidebar_instance_number = (int) $context['sidebar_instance_number'];
		}

		// Filter sidebars_widgets so that only the queried widget is in the sidebar.
		$this->rendering_widget_id = $widget_id;

		$filter_callback = array( $this, 'filter_sidebars_widgets_for_rendering_widget' );
		add_filter( 'sidebars_widgets', $filter_callback, 1000 );

		// Render the widget.
		ob_start();
		$this->rendering_sidebar_id = $context['sidebar_id'];
		dynamic_sidebar( $this->rendering_sidebar_id );
		$container = ob_get_clean();

		// Reset variables for next partial render.
		remove_filter( 'sidebars_widgets', $filter_callback, 1000 );

		$this->context_sidebar_instance_number = null;
		$this->rendering_sidebar_id            = null;
		$this->rendering_widget_id             = null;

		return $container;
	}

	//
	// Option Update Capturing.
	//

	/**
	 * List of captured widget option updates.
	 *
	 * @since 3.9.0
	 * @var array $_captured_options Values updated while option capture is happening.
	 */
	protected $_captured_options = array();

	/**
	 * Whether option capture is currently happening.
	 *
	 * @since 3.9.0
	 * @var bool $_is_current Whether option capture is currently happening or not.
	 */
	protected $_is_capturing_option_updates = false;

	/**
	 * Determines whether the captured option update should be ignored.
	 *
	 * @since 3.9.0
	 *
	 * @param string $option_name Option name.
	 * @return bool Whether the option capture is ignored.
	 */
	protected function is_option_capture_ignored( $option_name ) {
		return ( 0 === strpos( $option_name, '_transient_' ) );
	}

	/**
	 * Retrieves captured widget option updates.
	 *
	 * @since 3.9.0
	 *
	 * @return array Array of captured options.
	 */
	protected function get_captured_options() {
		return $this->_captured_options;
	}

	/**
	 * Retrieves the option that was captured from being saved.
	 *
	 * @since 4.2.0
	 *
	 * @param string $option_name   Option name.
	 * @param mixed  $default_value Optional. Default value to return if the option does not exist. Default false.
	 * @return mixed Value set for the option.
	 */
	protected function get_captured_option( $option_name, $default_value = false ) {
		if ( array_key_exists( $option_name, $this->_captured_options ) ) {
			$value = $this->_captured_options[ $option_name ];
		} else {
			$value = $default_value;
		}
		return $value;
	}

	/**
	 * Retrieves the number of captured widget option updates.
	 *
	 * @since 3.9.0
	 *
	 * @return int Number of updated options.
	 */
	protected function count_captured_options() {
		return count( $this->_captured_options );
	}

	/**
	 * Begins keeping track of changes to widget options, caching new values.
	 *
	 * @since 3.9.0
	 */
	protected function start_capturing_option_updates() {
		if ( $this->_is_capturing_option_updates ) {
			return;
		}

		$this->_is_capturing_option_updates = true;

		add_filter( 'pre_update_option', array( $this, 'capture_filter_pre_update_option' ), 10, 3 );
	}

	/**
	 * Pre-filters captured option values before updating.
	 *
	 * @since 3.9.0
	 *
	 * @param mixed  $new_value   The new option value.
	 * @param string $option_name Name of the option.
	 * @param mixed  $old_value   The old option value.
	 * @return mixed Filtered option value.
	 */
	public function capture_filter_pre_update_option( $new_value, $option_name, $old_value ) {
		if ( $this->is_option_capture_ignored( $option_name ) ) {
			return $new_value;
		}

		if ( ! isset( $this->_captured_options[ $option_name ] ) ) {
			add_filter( "pre_option_{$option_name}", array( $this, 'capture_filter_pre_get_option' ) );
		}

		$this->_captured_options[ $option_name ] = $new_value;

		return $old_value;
	}

	/**
	 * Pre-filters captured option values before retrieving.
	 *
	 * @since 3.9.0
	 *
	 * @param mixed $value Value to return instead of the option value.
	 * @return mixed Filtered option value.
	 */
	public function capture_filter_pre_get_option( $value ) {
		$option_name = preg_replace( '/^pre_option_/', '', current_filter() );

		if ( isset( $this->_captured_options[ $option_name ] ) ) {
			$value = $this->_captured_options[ $option_name ];

			/** This filter is documented in wp-includes/option.php */
			$value = apply_filters( 'option_' . $option_name, $value, $option_name );
		}

		return $value;
	}

	/**
	 * Undoes any changes to the options since options capture began.
	 *
	 * @since 3.9.0
	 */
	protected function stop_capturing_option_updates() {
		if ( ! $this->_is_capturing_option_updates ) {
			return;
		}

		remove_filter( 'pre_update_option', array( $this, 'capture_filter_pre_update_option' ), 10 );

		foreach ( array_keys( $this->_captured_options ) as $option_name ) {
			remove_filter( "pre_option_{$option_name}", array( $this, 'capture_filter_pre_get_option' ) );
		}

		$this->_captured_options            = array();
		$this->_is_capturing_option_updates = false;
	}

	/**
	 * {@internal Missing Summary}
	 *
	 * See the {@see 'customize_dynamic_setting_args'} filter.
	 *
	 * @since 3.9.0
	 * @deprecated 4.2.0 Deprecated in favor of the {@see 'customize_dynamic_setting_args'} filter.
	 */
	public function setup_widget_addition_previews() {
		_deprecated_function( __METHOD__, '4.2.0', 'customize_dynamic_setting_args' );
	}

	/**
	 * {@internal Missing Summary}
	 *
	 * See the {@see 'customize_dynamic_setting_args'} filter.
	 *
	 * @since 3.9.0
	 * @deprecated 4.2.0 Deprecated in favor of the {@see 'customize_dynamic_setting_args'} filter.
	 */
	public function prepreview_added_sidebars_widgets() {
		_deprecated_function( __METHOD__, '4.2.0', 'customize_dynamic_setting_args' );
	}

	/**
	 * {@internal Missing Summary}
	 *
	 * See the {@see 'customize_dynamic_setting_args'} filter.
	 *
	 * @since 3.9.0
	 * @deprecated 4.2.0 Deprecated in favor of the {@see 'customize_dynamic_setting_args'} filter.
	 */
	public function prepreview_added_widget_instance() {
		_deprecated_function( __METHOD__, '4.2.0', 'customize_dynamic_setting_args' );
	}

	/**
	 * {@internal Missing Summary}
	 *
	 * See the {@see 'customize_dynamic_setting_args'} filter.
	 *
	 * @since 3.9.0
	 * @deprecated 4.2.0 Deprecated in favor of the {@see 'customize_dynamic_setting_args'} filter.
	 */
	public function remove_prepreview_filters() {
		_deprecated_function( __METHOD__, '4.2.0', 'customize_dynamic_setting_args' );
	}
}