class-opengraph.php 28 KB
Newer Older
imac's avatar
imac committed
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
<?php
/**
 * @package WPSEO\Frontend
 */

/**
 * This code adds the OpenGraph output.
 */
class WPSEO_OpenGraph {

	/**
	 * @var array $options Options for the OpenGraph Settings
	 */
	public $options = array();

	/**
	 * Class constructor.
	 */
	public function __construct() {
		$this->options = WPSEO_Options::get_option( 'wpseo_social' );

		if ( isset( $GLOBALS['fb_ver'] ) || class_exists( 'Facebook_Loader', false ) ) {
			add_filter( 'fb_meta_tags', array( $this, 'facebook_filter' ), 10, 1 );
		}
		else {
			add_filter( 'language_attributes', array( $this, 'add_opengraph_namespace' ), 15 );

			add_action( 'wpseo_opengraph', array( $this, 'locale' ), 1 );
			add_action( 'wpseo_opengraph', array( $this, 'type' ), 5 );
			add_action( 'wpseo_opengraph', array( $this, 'og_title' ), 10 );
			add_action( 'wpseo_opengraph', array( $this, 'site_owner' ), 20 );
			add_action( 'wpseo_opengraph', array( $this, 'description' ), 11 );
			add_action( 'wpseo_opengraph', array( $this, 'url' ), 12 );
			add_action( 'wpseo_opengraph', array( $this, 'site_name' ), 13 );
			add_action( 'wpseo_opengraph', array( $this, 'website_facebook' ), 14 );
			if ( is_singular() && ! is_front_page() ) {
				add_action( 'wpseo_opengraph', array( $this, 'article_author_facebook' ), 15 );
				add_action( 'wpseo_opengraph', array( $this, 'tags' ), 16 );
				add_action( 'wpseo_opengraph', array( $this, 'category' ), 17 );
				add_action( 'wpseo_opengraph', array( $this, 'publish_date' ), 19 );
			}

			add_action( 'wpseo_opengraph', array( $this, 'image' ), 30 );
		}
		add_filter( 'jetpack_enable_open_graph', '__return_false' );
		add_action( 'wpseo_head', array( $this, 'opengraph' ), 30 );
	}

	/**
	 * Main OpenGraph output.
	 */
	public function opengraph() {
		wp_reset_query();
		/**
		 * Action: 'wpseo_opengraph' - Hook to add all Facebook OpenGraph output to so they're close together.
		 */
		do_action( 'wpseo_opengraph' );
	}

	/**
	 * Internal function to output FB tags. This also adds an output filter to each bit of output based on the property.
	 *
	 * @param string $property Property attribute value.
	 * @param string $content  Content attribute value.
	 *
	 * @return boolean
	 */
	public function og_tag( $property, $content ) {
		$og_property = str_replace( ':', '_', $property );
		/**
		 * Filter: 'wpseo_og_' . $og_property - Allow developers to change the content of specific OG meta tags.
		 *
		 * @api string $content The content of the property
		 */
		$content = apply_filters( 'wpseo_og_' . $og_property, $content );
		if ( empty( $content ) ) {
			return false;
		}

		echo '<meta property="', esc_attr( $property ), '" content="', esc_attr( $content ), '" />', "\n";

		return true;
	}

	/**
	 * Filter the Facebook plugins metadata
	 *
	 * @param array $meta_tags the array to fix.
	 *
	 * @return array $meta_tags
	 */
	public function facebook_filter( $meta_tags ) {
		$meta_tags['http://ogp.me/ns#type']  = $this->type( false );
		$meta_tags['http://ogp.me/ns#title'] = $this->og_title( false );

		// Filter the locale too because the Facebook plugin locale code is not as good as ours.
		$meta_tags['http://ogp.me/ns#locale'] = $this->locale( false );

		$ogdesc = $this->description( false );
		if ( ! empty( $ogdesc ) ) {
			$meta_tags['http://ogp.me/ns#description'] = $ogdesc;
		}

		return $meta_tags;
	}

	/**
	 * Filter for the namespace, adding the OpenGraph namespace.
	 *
	 * @link https://developers.facebook.com/docs/web/tutorials/scrumptious/open-graph-object/
	 *
	 * @param string $input The input namespace string.
	 *
	 * @return string
	 */
	public function add_opengraph_namespace( $input ) {
		$namespaces = array(
			'og: http://ogp.me/ns#',
		);
		if ( $this->options['fbadminapp'] != 0 || ( is_array( $this->options['fb_admins'] ) && $this->options['fb_admins'] !== array() ) ) {
			$namespaces[] = 'fb: http://ogp.me/ns/fb#';
		}

		/**
		 * Allow for adding additional namespaces to the <html> prefix attributes.
		 *
		 * @since 3.9.0
		 *
		 * @param array $namespaces Currently registered namespaces which are to be
		 *                          added to the prefix attribute.
		 *                          Namespaces are strings and have the following syntax:
		 *                          ns: http://url.to.namespace/definition
		 */
		$namespaces       = apply_filters( 'wpseo_html_namespaces', $namespaces );
		$namespace_string = implode( ' ', array_unique( $namespaces ) );

		if ( strpos( $input, ' prefix=' ) !== false ) {
			$regex   = '`prefix=([\'"])(.+?)\1`';
			$replace = 'prefix="$2 ' . $namespace_string . '"';
			$input   = preg_replace( $regex, $replace, $input );
		}
		else {
			$input .= ' prefix="' . $namespace_string . '"';
		}

		return $input;
	}

	/**
	 * Outputs the authors FB page.
	 *
	 * @link https://developers.facebook.com/blog/post/2013/06/19/platform-updates--new-open-graph-tags-for-media-publishers-and-more/
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 *
	 * @return boolean
	 */
	public function article_author_facebook() {
		if ( ! is_singular() ) {
			return false;
		}

		/**
		 * Filter: 'wpseo_opengraph_author_facebook' - Allow developers to filter the Yoast SEO post authors facebook profile URL
		 *
		 * @api bool|string $unsigned The Facebook author URL, return false to disable
		 */
		$facebook = apply_filters( 'wpseo_opengraph_author_facebook', get_the_author_meta( 'facebook', $GLOBALS['post']->post_author ) );

		if ( $facebook && ( is_string( $facebook ) && $facebook !== '' ) ) {
			$this->og_tag( 'article:author', $facebook );

			return true;
		}

		return false;
	}

	/**
	 * Outputs the websites FB page.
	 *
	 * @link https://developers.facebook.com/blog/post/2013/06/19/platform-updates--new-open-graph-tags-for-media-publishers-and-more/
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean
	 */
	public function website_facebook() {

		if ( 'article' === $this->type( false ) && ! empty( $this->options['facebook_site'] ) ) {
			$this->og_tag( 'article:publisher', $this->options['facebook_site'] );

			return true;
		}

		return false;
	}

	/**
	 * Outputs the site owner
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean
	 */
	public function site_owner() {
		if ( isset( $this->options['fbadminapp'] ) && $this->options['fbadminapp'] != 0 ) {
			$this->og_tag( 'fb:app_id', $this->options['fbadminapp'] );

			return true;
		}
		else if ( isset( $this->options['fb_admins'] ) && is_array( $this->options['fb_admins'] ) && $this->options['fb_admins'] !== array() ) {
			$adminstr = implode( ',', array_keys( $this->options['fb_admins'] ) );
			/**
			 * Filter: 'wpseo_opengraph_admin' - Allow developer to filter the fb:admins string put out by Yoast SEO
			 *
			 * @api string $adminstr The admin string
			 */
			$adminstr = apply_filters( 'wpseo_opengraph_admin', $adminstr );
			if ( is_string( $adminstr ) && $adminstr !== '' ) {

				$admins = explode( ',', $adminstr );

				foreach ( $admins as $admin_id ) {
					$this->og_tag( 'fb:admins', $admin_id );
				}

				return true;
			}
		}

		return false;
	}

	/**
	 * Outputs the SEO title as OpenGraph title.
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 *
	 * @param bool $echo Whether or not to echo the output.
	 *
	 * @return string|boolean
	 */
	public function og_title( $echo = true ) {

		$frontend      = WPSEO_Frontend::get_instance();
		$is_posts_page = $frontend->is_posts_page();

		if ( is_singular() || $is_posts_page ) {

			$post_id = ( $is_posts_page ) ? get_option( 'page_for_posts' ) : get_the_ID();
			$post    = get_post( $post_id );
			$title   = WPSEO_Meta::get_value( 'opengraph-title', $post_id );

			if ( $title === '' ) {
				$title = $frontend->title( '' );
			}
			else {
				// Replace Yoast SEO Variables.
				$title = wpseo_replace_vars( $title, $post );
			}
		}
		else if ( is_front_page() ) {
			$title = ( isset( $this->options['og_frontpage_title'] ) && $this->options['og_frontpage_title'] !== '' ) ? $this->options['og_frontpage_title'] : $frontend->title( '' );
		}
		elseif ( is_category() || is_tax() || is_tag() ) {
			$title = WPSEO_Taxonomy_Meta::get_meta_without_term( 'opengraph-title' );
			if ( $title === '' ) {
				$title = $frontend->title( '' );
			}
			else {
				// Replace Yoast SEO Variables.
				$title = wpseo_replace_vars( $title, $GLOBALS['wp_query']->get_queried_object() );
			}
		}
		else {
			$title = $frontend->title( '' );
		}

		/**
		 * Filter: 'wpseo_opengraph_title' - Allow changing the title specifically for OpenGraph
		 *
		 * @api string $unsigned The title string
		 */
		$title = trim( apply_filters( 'wpseo_opengraph_title', $title ) );

		if ( is_string( $title ) && $title !== '' ) {
			if ( $echo !== false ) {
				$this->og_tag( 'og:title', $title );

				return true;
			}
		}

		if ( $echo === false ) {
			return $title;
		}

		return false;
	}

	/**
	 * Outputs the canonical URL as OpenGraph URL, which consolidates likes and shares.
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean
	 */
	public function url() {
		/**
		 * Filter: 'wpseo_opengraph_url' - Allow changing the OpenGraph URL
		 *
		 * @api string $unsigned Canonical URL
		 */
		$url = apply_filters( 'wpseo_opengraph_url', WPSEO_Frontend::get_instance()->canonical( false ) );

		if ( is_string( $url ) && $url !== '' ) {
			$this->og_tag( 'og:url', esc_url( $url ) );

			return true;
		}

		return false;
	}

	/**
	 * Output the locale, doing some conversions to make sure the proper Facebook locale is outputted.
	 *
	 * Last update/compare with FB list done on 2015-03-16 by Rarst
	 *
	 * @see  http://www.facebook.com/translations/FacebookLocales.xml for the list of supported locales
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 *
	 * @param bool $echo Whether to echo or return the locale.
	 *
	 * @return string $locale
	 */
	public function locale( $echo = true ) {
		/**
		 * Filter: 'wpseo_locale' - Allow changing the locale output
		 *
		 * @api string $unsigned Locale string
		 */
		$locale = apply_filters( 'wpseo_locale', get_locale() );

		// Catch some weird locales served out by WP that are not easily doubled up.
		$fix_locales = array(
			'ca' => 'ca_ES',
			'en' => 'en_US',
			'el' => 'el_GR',
			'et' => 'et_EE',
			'ja' => 'ja_JP',
			'sq' => 'sq_AL',
			'uk' => 'uk_UA',
			'vi' => 'vi_VN',
			'zh' => 'zh_CN',
		);

		if ( isset( $fix_locales[ $locale ] ) ) {
			$locale = $fix_locales[ $locale ];
		}

		// Convert locales like "es" to "es_ES", in case that works for the given locale (sometimes it does).
		if ( strlen( $locale ) == 2 ) {
			$locale = strtolower( $locale ) . '_' . strtoupper( $locale );
		}

		// These are the locales FB supports.
		$fb_valid_fb_locales = array(
			'af_ZA', // Afrikaans.
			'ak_GH', // Akan.
			'am_ET', // Amharic.
			'ar_AR', // Arabic.
			'as_IN', // Assamese.
			'ay_BO', // Aymara.
			'az_AZ', // Azerbaijani.
			'be_BY', // Belarusian.
			'bg_BG', // Bulgarian.
			'bn_IN', // Bengali.
			'br_FR', // Breton.
			'bs_BA', // Bosnian.
			'ca_ES', // Catalan.
			'cb_IQ', // Sorani Kurdish.
			'ck_US', // Cherokee.
			'co_FR', // Corsican.
			'cs_CZ', // Czech.
			'cx_PH', // Cebuano.
			'cy_GB', // Welsh.
			'da_DK', // Danish.
			'de_DE', // German.
			'el_GR', // Greek.
			'en_GB', // English (UK).
			'en_IN', // English (India).
			'en_PI', // English (Pirate).
			'en_UD', // English (Upside Down).
			'en_US', // English (US).
			'eo_EO', // Esperanto.
			'es_CL', // Spanish (Chile).
			'es_CO', // Spanish (Colombia).
			'es_ES', // Spanish (Spain).
			'es_LA', // Spanish.
			'es_MX', // Spanish (Mexico).
			'es_VE', // Spanish (Venezuela).
			'et_EE', // Estonian.
			'eu_ES', // Basque.
			'fa_IR', // Persian.
			'fb_LT', // Leet Speak.
			'ff_NG', // Fulah.
			'fi_FI', // Finnish.
			'fo_FO', // Faroese.
			'fr_CA', // French (Canada).
			'fr_FR', // French (France).
			'fy_NL', // Frisian.
			'ga_IE', // Irish.
			'gl_ES', // Galician.
			'gn_PY', // Guarani.
			'gu_IN', // Gujarati.
			'gx_GR', // Classical Greek.
			'ha_NG', // Hausa.
			'he_IL', // Hebrew.
			'hi_IN', // Hindi.
			'hr_HR', // Croatian.
			'hu_HU', // Hungarian.
			'hy_AM', // Armenian.
			'id_ID', // Indonesian.
			'ig_NG', // Igbo.
			'is_IS', // Icelandic.
			'it_IT', // Italian.
			'ja_JP', // Japanese.
			'ja_KS', // Japanese (Kansai).
			'jv_ID', // Javanese.
			'ka_GE', // Georgian.
			'kk_KZ', // Kazakh.
			'km_KH', // Khmer.
			'kn_IN', // Kannada.
			'ko_KR', // Korean.
			'ku_TR', // Kurdish (Kurmanji).
			'ky_KG', // Kyrgyz.
			'la_VA', // Latin.
			'lg_UG', // Ganda.
			'li_NL', // Limburgish.
			'ln_CD', // Lingala.
			'lo_LA', // Lao.
			'lt_LT', // Lithuanian.
			'lv_LV', // Latvian.
			'mg_MG', // Malagasy.
			'mi_NZ', // Maori.
			'mk_MK', // Macedonian.
			'ml_IN', // Malayalam.
			'mn_MN', // Mongolian.
			'mr_IN', // Marathi.
			'ms_MY', // Malay.
			'mt_MT', // Maltese.
			'my_MM', // Burmese.
			'nb_NO', // Norwegian (bokmal).
			'nd_ZW', // Ndebele.
			'ne_NP', // Nepali.
			'nl_BE', // Dutch (Belgie).
			'nl_NL', // Dutch.
			'nn_NO', // Norwegian (nynorsk).
			'ny_MW', // Chewa.
			'or_IN', // Oriya.
			'pa_IN', // Punjabi.
			'pl_PL', // Polish.
			'ps_AF', // Pashto.
			'pt_BR', // Portuguese (Brazil).
			'pt_PT', // Portuguese (Portugal).
			'qu_PE', // Quechua.
			'rm_CH', // Romansh.
			'ro_RO', // Romanian.
			'ru_RU', // Russian.
			'rw_RW', // Kinyarwanda.
			'sa_IN', // Sanskrit.
			'sc_IT', // Sardinian.
			'se_NO', // Northern Sami.
			'si_LK', // Sinhala.
			'sk_SK', // Slovak.
			'sl_SI', // Slovenian.
			'sn_ZW', // Shona.
			'so_SO', // Somali.
			'sq_AL', // Albanian.
			'sr_RS', // Serbian.
			'sv_SE', // Swedish.
			'sw_KE', // Swahili.
			'sy_SY', // Syriac.
			'sz_PL', // Silesian.
			'ta_IN', // Tamil.
			'te_IN', // Telugu.
			'tg_TJ', // Tajik.
			'th_TH', // Thai.
			'tk_TM', // Turkmen.
			'tl_PH', // Filipino.
			'tl_ST', // Klingon.
			'tr_TR', // Turkish.
			'tt_RU', // Tatar.
			'tz_MA', // Tamazight.
			'uk_UA', // Ukrainian.
			'ur_PK', // Urdu.
			'uz_UZ', // Uzbek.
			'vi_VN', // Vietnamese.
			'wo_SN', // Wolof.
			'xh_ZA', // Xhosa.
			'yi_DE', // Yiddish.
			'yo_NG', // Yoruba.
			'zh_CN', // Simplified Chinese (China).
			'zh_HK', // Traditional Chinese (Hong Kong).
			'zh_TW', // Traditional Chinese (Taiwan).
			'zu_ZA', // Zulu.
			'zz_TR', // Zazaki.
		);

		// Check to see if the locale is a valid FB one, if not, use en_US as a fallback.
		if ( ! in_array( $locale, $fb_valid_fb_locales ) ) {
			$locale = strtolower( substr( $locale, 0, 2 ) ) . '_' . strtoupper( substr( $locale, 0, 2 ) );
			if ( ! in_array( $locale, $fb_valid_fb_locales ) ) {
				$locale = 'en_US';
			}
		}

		if ( $echo !== false ) {
			$this->og_tag( 'og:locale', $locale );
		}

		return $locale;
	}

	/**
	 * Output the OpenGraph type.
	 *
	 * @param boolean $echo Whether to echo or return the type.
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/object/
	 *
	 * @return string $type
	 */
	public function type( $echo = true ) {

		if ( is_front_page() || is_home() ) {
			$type = 'website';
		}
		elseif ( is_singular() ) {

			// This'll usually only be changed by plugins right now.
			$type = WPSEO_Meta::get_value( 'og_type' );

			if ( $type === '' ) {
				$type = 'article';
			}
		}
		else {
			// We use "object" for archives etc. as article doesn't apply there.
			$type = 'object';
		}

		/**
		 * Filter: 'wpseo_opengraph_type' - Allow changing the OpenGraph type of the page
		 *
		 * @api string $type The OpenGraph type string.
		 */
		$type = apply_filters( 'wpseo_opengraph_type', $type );

		if ( is_string( $type ) && $type !== '' ) {
			if ( $echo !== false ) {
				$this->og_tag( 'og:type', $type );
			}
			else {
				return $type;
			}
		}

		return '';
	}

	/**
	 * Create new WPSEO_OpenGraph_Image class and get the images to set the og:image
	 *
	 * @param string|boolean $image Optional image URL.
	 */
	public function image( $image = false ) {
		$opengraph_images = new WPSEO_OpenGraph_Image( $this->options, $image );

		foreach ( $opengraph_images->get_images() as $img ) {
			$this->og_tag( 'og:image', esc_url( $img ) );
		}

		$dimensions = $opengraph_images->get_dimensions();

		if ( ! empty( $dimensions['width'] ) ) {
			$this->og_tag( 'og:image:width', absint( $dimensions['width'] ) );
		}

		if ( ! empty( $dimensions['height'] ) ) {
			$this->og_tag( 'og:image:height', absint( $dimensions['height'] ) );
		}
	}

	/**
	 * Fallback method for plugins using image_output
	 *
	 * @param string $image Image URL.
	 */
	public function image_output( $image ) {
		$this->image( $image );
	}

	/**
	 * Output the OpenGraph description, specific OG description first, if not, grab the meta description.
	 *
	 * @param bool $echo Whether to echo or return the description.
	 *
	 * @return string $ogdesc
	 */
	public function description( $echo = true ) {
		$ogdesc   = '';
		$frontend = WPSEO_Frontend::get_instance();

		if ( is_front_page() ) {
			if ( isset( $this->options['og_frontpage_desc'] ) && $this->options['og_frontpage_desc'] !== '' ) {
				$ogdesc = wpseo_replace_vars( $this->options['og_frontpage_desc'], null );
			}
			else {
				$ogdesc = $frontend->metadesc( false );
			}
		}

		$is_posts_page = $frontend->is_posts_page();

		if ( is_singular() || $is_posts_page ) {
			$post_id = ( $is_posts_page ) ? get_option( 'page_for_posts' ) : get_the_ID();
			$post    = get_post( $post_id );
			$ogdesc  = WPSEO_Meta::get_value( 'opengraph-description', $post_id );

			// Replace Yoast SEO Variables.
			$ogdesc = wpseo_replace_vars( $ogdesc, $post );

			// Use metadesc if $ogdesc is empty.
			if ( $ogdesc === '' ) {
				$ogdesc = $frontend->metadesc( false );
			}

			// Tag og:description is still blank so grab it from get_the_excerpt().
			if ( ! is_string( $ogdesc ) || ( is_string( $ogdesc ) && $ogdesc === '' ) ) {
				$ogdesc = str_replace( '[&hellip;]', '&hellip;', strip_tags( get_the_excerpt() ) );
			}
		}

		if ( is_category() || is_tag() || is_tax() ) {
			$ogdesc = WPSEO_Taxonomy_Meta::get_meta_without_term( 'opengraph-description' );
			if ( $ogdesc === '' ) {
				$ogdesc = $frontend->metadesc( false );
			}

			if ( $ogdesc === '' ) {
				$ogdesc = trim( strip_tags( term_description() ) );
			}

			if ( $ogdesc === '' ) {
				$ogdesc = WPSEO_Taxonomy_Meta::get_meta_without_term( 'desc' );
			}
		}

		// Strip shortcodes if any.
		$ogdesc = strip_shortcodes( $ogdesc );

		/**
		 * Filter: 'wpseo_opengraph_desc' - Allow changing the OpenGraph description
		 *
		 * @api string $ogdesc The description string.
		 */
		$ogdesc = trim( apply_filters( 'wpseo_opengraph_desc', $ogdesc ) );

		if ( is_string( $ogdesc ) && $ogdesc !== '' ) {
			if ( $echo !== false ) {
				$this->og_tag( 'og:description', $ogdesc );
			}
		}

		return $ogdesc;
	}

	/**
	 * Output the site name straight from the blog info.
	 */
	public function site_name() {
		/**
		 * Filter: 'wpseo_opengraph_site_name' - Allow changing the OpenGraph site name
		 *
		 * @api string $unsigned Blog name string
		 */
		$name = apply_filters( 'wpseo_opengraph_site_name', get_bloginfo( 'name' ) );
		if ( is_string( $name ) && $name !== '' ) {
			$this->og_tag( 'og:site_name', $name );
		}
	}

	/**
	 * Output the article tags as article:tag tags.
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean
	 */
	public function tags() {
		if ( ! is_singular() ) {
			return false;
		}

		$tags = get_the_tags();
		if ( ! is_wp_error( $tags ) && ( is_array( $tags ) && $tags !== array() ) ) {

			foreach ( $tags as $tag ) {
				$this->og_tag( 'article:tag', $tag->name );
			}

			return true;
		}

		return false;
	}

	/**
	 * Output the article category as an article:section tag.
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean;
	 */
	public function category() {

		if ( ! is_singular() ) {
			return false;
		}

		$terms = get_the_category();

		if ( ! is_wp_error( $terms ) && ( is_array( $terms ) && $terms !== array() ) ) {

			// We can only show one section here, so we take the first one.
			$this->og_tag( 'article:section', $terms[0]->name );

			return true;
		}

		return false;
	}

	/**
	 * Output the article publish and last modification date
	 *
	 * @link https://developers.facebook.com/docs/reference/opengraph/object-type/article/
	 * @return boolean;
	 */
	public function publish_date() {

		if ( ! is_singular( 'post' ) ) {
			/**
			 * Filter: 'wpseo_opengraph_show_publish_date' - Allow showing publication date for other post types
			 *
			 * @api bool $unsigned Whether or not to show publish date
			 *
			 * @param string $post_type The current URL's post type.
			 */
			if ( false === apply_filters( 'wpseo_opengraph_show_publish_date', false, get_post_type() ) ) {
				return false;
			}
		}

		$pub = get_the_date( DATE_W3C );
		$this->og_tag( 'article:published_time', $pub );

		$mod = get_the_modified_date( DATE_W3C );
		if ( $mod != $pub ) {
			$this->og_tag( 'article:modified_time', $mod );
			$this->og_tag( 'og:updated_time', $mod );
		}

		return true;
	}
} /* End of class */

/**
 * Class WPSEO_OpenGraph_Image
 */
class WPSEO_OpenGraph_Image {

	/**
	 * @var array $options Holds options passed to the constructor
	 */
	private $options;

	/**
	 * @var array $images Holds the images that have been put out as OG image.
	 */
	private $images = array();

	/**
	 * @TODO This needs to be refactored since we only hold one set of dimensions for multiple images. R.
	 * @var array $dimensions Holds image dimensions, if determined.
	 */
	protected $dimensions = array();

	/**
	 * Constructor
	 *
	 * @param array          $options Options set.
	 * @param string|boolean $image   Optional image URL.
	 */
	public function __construct( $options, $image = false ) {
		$this->options = $options;

		if ( ! empty( $image ) && $this->add_image( $image ) ) {
			// Safely assume an image was added so we don't need to automatically determine it anymore.
		}
		else {
			$this->set_images();
		}
	}

	/**
	 * Return the images array
	 *
	 * @return array
	 */
	public function get_images() {
		return $this->images;
	}

	/**
	 * Return the dimensions array.
	 *
	 * @return array
	 */
	public function get_dimensions() {
		return $this->dimensions;
	}

	/**
	 * Display an OpenGraph image tag
	 *
	 * @param string $img - Source URL to the image.
	 *
	 * @return bool
	 */
	public function add_image( $img ) {

		$original = trim( $img );

		// Filter: 'wpseo_opengraph_image' - Allow changing the OpenGraph image.
		$img = trim( apply_filters( 'wpseo_opengraph_image', $img ) );

		if ( $original !== $img ) {
			$this->dimensions = array();
		}

		if ( empty( $img ) ) {
			return false;
		}

		if ( WPSEO_Utils::is_url_relative( $img ) === true ) {
			$img = $this->get_relative_path( $img );
		}

		if ( in_array( $img, $this->images ) ) {
			return false;
		}
		array_push( $this->images, $img );

		return true;
	}

	/**
	 * Check if page is front page or singular and call the corresponding functions. If not, call get_default_image.
	 */
	private function set_images() {

		/**
		 * Filter: wpseo_add_opengraph_images - Allow developers to add images to the OpenGraph tags
		 *
		 * @api WPSEO_OpenGraph_Image The current object.
		 */
		do_action( 'wpseo_add_opengraph_images', $this );

		if ( is_front_page() ) {
			$this->get_front_page_image();
		}
		elseif ( is_home() ) { // Posts page, which won't be caught by is_singular() below.
			$this->get_posts_page_image();
		}

		if ( is_singular() ) {
			$this->get_singular_image();
		}

		if ( is_category() || is_tax() || is_tag() ) {
			$this->get_opengraph_image_taxonomy();
		}

		$this->get_default_image();
	}

	/**
	 * If the frontpage image exists, call add_image
	 */
	private function get_front_page_image() {
		if ( $this->options['og_frontpage_image'] !== '' ) {
			$this->add_image( $this->options['og_frontpage_image'] );
		}
	}

	/**
	 * Get the images of the posts page.
	 */
	private function get_posts_page_image() {

		$post_id = get_option( 'page_for_posts' );

		if ( $this->get_opengraph_image_post( $post_id ) ) {
			return;
		}

		if ( $this->get_featured_image( $post_id ) ) {
			return;
		}
	}

	/**
	 * Get the images of the singular post.
	 */
	private function get_singular_image() {
		global $post;

		if ( $this->get_opengraph_image_post() ) {
			return;
		}

		if ( $this->get_attachment_page_image( $post->ID ) ) {
			return;
		}

		if ( $this->get_featured_image( $post->ID ) ) {
			return;
		}

		$this->get_content_images( $post );
	}

	/**
	 * Get default image and call add_image
	 */
	private function get_default_image() {
		if ( count( $this->images ) === 0 && isset( $this->options['og_default_image'] ) && $this->options['og_default_image'] !== '' ) {
			$this->add_image( $this->options['og_default_image'] );
		}
	}

	/**
	 * If opengraph-image is set, call add_image and return true.
	 *
	 * @param int $post_id Optional post ID to use.
	 *
	 * @return bool
	 */
	private function get_opengraph_image_post( $post_id = 0 ) {
		$ogimg = WPSEO_Meta::get_value( 'opengraph-image', $post_id );
		if ( $ogimg !== '' ) {
			$this->add_image( $ogimg );

			return true;
		}

		return false;
	}

	/**
	 * Check if taxonomy has an image and add this image
	 */
	private function get_opengraph_image_taxonomy() {
		if ( ( $ogimg = WPSEO_Taxonomy_Meta::get_meta_without_term( 'opengraph-image' ) ) !== '' ) {
			$this->add_image( $ogimg );
		}
	}

	/**
	 * If there is a featured image, check image size. If image size is correct, call add_image and return true
	 *
	 * @param int $post_id The post ID.
	 *
	 * @return bool
	 */
	private function get_featured_image( $post_id ) {

		if ( has_post_thumbnail( $post_id ) ) {
			/**
			 * Filter: 'wpseo_opengraph_image_size' - Allow changing the image size used for OpenGraph sharing
			 *
			 * @api string $unsigned Size string
			 */
			$thumb = wp_get_attachment_image_src( get_post_thumbnail_id( $post_id ), apply_filters( 'wpseo_opengraph_image_size', 'original' ) );

			if ( $this->check_featured_image_size( $thumb ) ) {

				$this->dimensions['width']  = $thumb[1];
				$this->dimensions['height'] = $thumb[2];

				return $this->add_image( $thumb[0] );
			}
		}

		return false;
	}

	/**
	 * If this is an attachment page, call add_image with the attachment and return true
	 *
	 * @param int $post_id The post ID.
	 *
	 * @return bool
	 */
	private function get_attachment_page_image( $post_id ) {
		if ( get_post_type( $post_id ) === 'attachment' ) {
			$mime_type = get_post_mime_type( $post_id );
			switch ( $mime_type ) {
				case 'image/jpeg':
				case 'image/png':
				case 'image/gif':
					return $this->add_image( wp_get_attachment_url( $post_id ) );
			}
		}

		return false;
	}

	/**
	 * Filter: 'wpseo_pre_analysis_post_content' - Allow filtering the content before analysis
	 *
	 * @api string $post_content The Post content string
	 *
	 * @param object $post - The post object.
	 */
	private function get_content_images( $post ) {
		$content = apply_filters( 'wpseo_pre_analysis_post_content', $post->post_content, $post );

		if ( preg_match_all( '`<img [^>]+>`', $content, $matches ) ) {
			foreach ( $matches[0] as $img ) {
				if ( preg_match( '`src=(["\'])(.*?)\1`', $img, $match ) ) {
					$this->add_image( $match[2] );
				}
			}
		}
	}

	/**
	 * Check size of featured image. If image is too small, return false, else return true
	 *
	 * @param array $img_data wp_get_attachment_image_src: url, width, height, icon.
	 *
	 * @return bool
	 */
	private function check_featured_image_size( $img_data ) {

		if ( ! is_array( $img_data ) ) {
			return false;
		}

		// Get the width and height of the image.
		if ( $img_data[1] < 200 || $img_data[2] < 200 ) {
			return false;
		}

		return true;
	}

	/**
	 * Get the relative path of the image
	 *
	 * @param array $img Image data array.
	 *
	 * @return bool|string
	 */
	private function get_relative_path( $img ) {
		if ( $img[0] != '/' ) {
			return false;
		}

		// If it's a relative URL, it's relative to the domain, not necessarily to the WordPress install, we
		// want to preserve domain name and URL scheme (http / https) though.
		$parsed_url = wp_parse_url( home_url() );
		$img        = $parsed_url['scheme'] . '://' . $parsed_url['host'] . $img;

		return $img;
	}
}