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   1  <?php
   2  /**
   3   * Twenty Fourteen Featured Content
   4   *
   5   * This module allows you to define a subset of posts to be displayed
   6   * in the theme's Featured Content area.
   7   *
   8   * For maximum compatibility with different methods of posting users
   9   * will designate a featured post tag to associate posts with. Since
  10   * this tag now has special meaning beyond that of a normal tags, users
  11   * will have the ability to hide it from the front-end of their site.
  12   */
  13  class Featured_Content {
  14  
  15      /**
  16       * The maximum number of posts a Featured Content area can contain.
  17       *
  18       * We define a default value here but themes can override
  19       * this by defining a "max_posts" entry in the second parameter
  20       * passed in the call to add_theme_support( 'featured-content' ).
  21       *
  22       * @see Featured_Content::init()
  23       *
  24       * @since Twenty Fourteen 1.0
  25       *
  26       * @static
  27       * @access public
  28       * @var int
  29       */
  30      public static $max_posts = 15;
  31  
  32      /**
  33       * Instantiate.
  34       *
  35       * All custom functionality will be hooked into the "init" action.
  36       *
  37       * @static
  38       * @access public
  39       * @since Twenty Fourteen 1.0
  40       */
  41  	public static function setup() {
  42          add_action( 'init', array( __CLASS__, 'init' ), 30 );
  43      }
  44  
  45      /**
  46       * Conditionally hook into WordPress.
  47       *
  48       * Theme must declare that they support this module by adding
  49       * add_theme_support( 'featured-content' ); during after_setup_theme.
  50       *
  51       * If no theme support is found there is no need to hook into WordPress.
  52       * We'll just return early instead.
  53       *
  54       * @static
  55       * @access public
  56       * @since Twenty Fourteen 1.0
  57       */
  58  	public static function init() {
  59          $theme_support = get_theme_support( 'featured-content' );
  60  
  61          // Return early if theme does not support Featured Content.
  62          if ( ! $theme_support ) {
  63              return;
  64          }
  65  
  66          /*
  67           * An array of named arguments must be passed as the second parameter
  68           * of add_theme_support().
  69           */
  70          if ( ! isset( $theme_support[0] ) ) {
  71              return;
  72          }
  73  
  74          // Return early if "featured_content_filter" has not been defined.
  75          if ( ! isset( $theme_support[0]['featured_content_filter'] ) ) {
  76              return;
  77          }
  78  
  79          $filter = $theme_support[0]['featured_content_filter'];
  80  
  81          // Theme can override the number of max posts.
  82          if ( isset( $theme_support[0]['max_posts'] ) ) {
  83              self::$max_posts = absint( $theme_support[0]['max_posts'] );
  84          }
  85  
  86          add_filter( $filter,                              array( __CLASS__, 'get_featured_posts' )    );
  87          add_action( 'customize_register',                 array( __CLASS__, 'customize_register' ), 9 );
  88          add_action( 'admin_init',                         array( __CLASS__, 'register_setting'   )    );
  89          add_action( 'save_post',                          array( __CLASS__, 'delete_transient'   )    );
  90          add_action( 'delete_post_tag',                    array( __CLASS__, 'delete_post_tag'    )    );
  91          add_action( 'customize_controls_enqueue_scripts', array( __CLASS__, 'enqueue_scripts'    )    );
  92          add_action( 'pre_get_posts',                      array( __CLASS__, 'pre_get_posts'      )    );
  93          add_action( 'wp_loaded',                          array( __CLASS__, 'wp_loaded'          )    );
  94      }
  95  
  96      /**
  97       * Hide "featured" tag from the front-end.
  98       *
  99       * Has to run on wp_loaded so that the preview filters of the customizer
 100       * have a chance to alter the value.
 101       *
 102       * @static
 103       * @access public
 104       * @since Twenty Fourteen 1.0
 105       */
 106  	public static function wp_loaded() {
 107          if ( self::get_setting( 'hide-tag' ) ) {
 108              add_filter( 'get_terms',     array( __CLASS__, 'hide_featured_term'     ), 10, 2 );
 109              add_filter( 'get_the_terms', array( __CLASS__, 'hide_the_featured_term' ), 10, 3 );
 110          }
 111      }
 112  
 113      /**
 114       * Get featured posts.
 115       *
 116       * @static
 117       * @access public
 118       * @since Twenty Fourteen 1.0
 119       *
 120       * @return array Array of featured posts.
 121       */
 122  	public static function get_featured_posts() {
 123          $post_ids = self::get_featured_post_ids();
 124  
 125          // No need to query if there is are no featured posts.
 126          if ( empty( $post_ids ) ) {
 127              return array();
 128          }
 129  
 130          $featured_posts = get_posts( array(
 131              'include'        => $post_ids,
 132              'posts_per_page' => count( $post_ids ),
 133          ) );
 134  
 135          return $featured_posts;
 136      }
 137  
 138      /**
 139       * Get featured post IDs
 140       *
 141       * This function will return the an array containing the
 142       * post IDs of all featured posts.
 143       *
 144       * Sets the "featured_content_ids" transient.
 145       *
 146       * @static
 147       * @access public
 148       * @since Twenty Fourteen 1.0
 149       *
 150       * @return array Array of post IDs.
 151       */
 152  	public static function get_featured_post_ids() {
 153          // Return array of cached results if they exist.
 154          $featured_ids = get_transient( 'featured_content_ids' );
 155          if ( ! empty( $featured_ids ) ) {
 156              return array_map( 'absint', (array) $featured_ids );
 157          }
 158  
 159          $settings = self::get_setting();
 160  
 161          // Return sticky post ids if no tag name is set.
 162          $term = get_term_by( 'name', $settings['tag-name'], 'post_tag' );
 163          if ( $term ) {
 164              $tag = $term->term_id;
 165          } else {
 166              return self::get_sticky_posts();
 167          }
 168  
 169          // Query for featured posts.
 170          $featured = get_posts( array(
 171              'numberposts' => $settings['quantity'],
 172              'tax_query'   => array(
 173                  array(
 174                      'field'    => 'term_id',
 175                      'taxonomy' => 'post_tag',
 176                      'terms'    => $tag,
 177                  ),
 178              ),
 179          ) );
 180  
 181          // Return array with sticky posts if no Featured Content exists.
 182          if ( ! $featured ) {
 183              return self::get_sticky_posts();
 184          }
 185  
 186          // Ensure correct format before save/return.
 187          $featured_ids = wp_list_pluck( (array) $featured, 'ID' );
 188          $featured_ids = array_map( 'absint', $featured_ids );
 189  
 190          set_transient( 'featured_content_ids', $featured_ids );
 191  
 192          return $featured_ids;
 193      }
 194  
 195      /**
 196       * Return an array with IDs of posts maked as sticky.
 197       *
 198       * @static
 199       * @access public
 200       * @since Twenty Fourteen 1.0
 201       *
 202       * @return array Array of sticky posts.
 203       */
 204  	public static function get_sticky_posts() {
 205          $settings = self::get_setting();
 206          return array_slice( get_option( 'sticky_posts', array() ), 0, $settings['quantity'] );
 207      }
 208  
 209      /**
 210       * Delete featured content ids transient.
 211       *
 212       * Hooks in the "save_post" action.
 213       *
 214       * @see Featured_Content::validate_settings().
 215       *
 216       * @static
 217       * @access public
 218       * @since Twenty Fourteen 1.0
 219       */
 220  	public static function delete_transient() {
 221          delete_transient( 'featured_content_ids' );
 222      }
 223  
 224      /**
 225       * Exclude featured posts from the home page blog query.
 226       *
 227       * Filter the home page posts, and remove any featured post ID's from it.
 228       * Hooked onto the 'pre_get_posts' action, this changes the parameters of
 229       * the query before it gets any posts.
 230       *
 231       * @static
 232       * @access public
 233       * @since Twenty Fourteen 1.0
 234       *
 235       * @param WP_Query $query WP_Query object.
 236       * @return WP_Query Possibly-modified WP_Query.
 237       */
 238  	public static function pre_get_posts( $query ) {
 239  
 240          // Bail if not home or not main query.
 241          if ( ! $query->is_home() || ! $query->is_main_query() ) {
 242              return;
 243          }
 244  
 245          $page_on_front = get_option( 'page_on_front' );
 246  
 247          // Bail if the blog page is not the front page.
 248          if ( ! empty( $page_on_front ) ) {
 249              return;
 250          }
 251  
 252          $featured = self::get_featured_post_ids();
 253  
 254          // Bail if no featured posts.
 255          if ( ! $featured ) {
 256              return;
 257          }
 258  
 259          // We need to respect post ids already in the blacklist.
 260          $post__not_in = $query->get( 'post__not_in' );
 261  
 262          if ( ! empty( $post__not_in ) ) {
 263              $featured = array_merge( (array) $post__not_in, $featured );
 264              $featured = array_unique( $featured );
 265          }
 266  
 267          $query->set( 'post__not_in', $featured );
 268      }
 269  
 270      /**
 271       * Reset tag option when the saved tag is deleted.
 272       *
 273       * It's important to mention that the transient needs to be deleted,
 274       * too. While it may not be obvious by looking at the function alone,
 275       * the transient is deleted by Featured_Content::validate_settings().
 276       *
 277       * Hooks in the "delete_post_tag" action.
 278       *
 279       * @see Featured_Content::validate_settings().
 280       *
 281       * @static
 282       * @access public
 283       * @since Twenty Fourteen 1.0
 284       *
 285       * @param int $tag_id The term_id of the tag that has been deleted.
 286       * @return void
 287       */
 288  	public static function delete_post_tag( $tag_id ) {
 289          $settings = self::get_setting();
 290  
 291          if ( empty( $settings['tag-id'] ) || $tag_id != $settings['tag-id'] ) {
 292              return;
 293          }
 294  
 295          $settings['tag-id'] = 0;
 296          $settings = self::validate_settings( $settings );
 297          update_option( 'featured-content', $settings );
 298      }
 299  
 300      /**
 301       * Hide featured tag from displaying when global terms are queried from the front-end.
 302       *
 303       * Hooks into the "get_terms" filter.
 304       *
 305       * @static
 306       * @access public
 307       * @since Twenty Fourteen 1.0
 308       *
 309       * @param array $terms      List of term objects. This is the return value of get_terms().
 310       * @param array $taxonomies An array of taxonomy slugs.
 311       * @return array A filtered array of terms.
 312       *
 313       * @uses Featured_Content::get_setting()
 314       */
 315  	public static function hide_featured_term( $terms, $taxonomies ) {
 316  
 317          // This filter is only appropriate on the front-end.
 318          if ( is_admin() ) {
 319              return $terms;
 320          }
 321  
 322          // We only want to hide the featured tag.
 323          if ( ! in_array( 'post_tag', $taxonomies ) ) {
 324              return $terms;
 325          }
 326  
 327          // Bail if no terms were returned.
 328          if ( empty( $terms ) ) {
 329              return $terms;
 330          }
 331  
 332          foreach( $terms as $order => $term ) {
 333              if ( self::get_setting( 'tag-id' ) == $term->term_id && 'post_tag' == $term->taxonomy ) {
 334                  unset( $terms[ $order ] );
 335              }
 336          }
 337  
 338          return $terms;
 339      }
 340  
 341      /**
 342       * Hide featured tag from display when terms associated with a post object
 343       * are queried from the front-end.
 344       *
 345       * Hooks into the "get_the_terms" filter.
 346       *
 347       * @static
 348       * @access public
 349       * @since Twenty Fourteen 1.0
 350       *
 351       * @param array $terms    A list of term objects. This is the return value of get_the_terms().
 352       * @param int   $id       The ID field for the post object that terms are associated with.
 353       * @param array $taxonomy An array of taxonomy slugs.
 354       * @return array Filtered array of terms.
 355       *
 356       * @uses Featured_Content::get_setting()
 357       */
 358  	public static function hide_the_featured_term( $terms, $id, $taxonomy ) {
 359  
 360          // This filter is only appropriate on the front-end.
 361          if ( is_admin() ) {
 362              return $terms;
 363          }
 364  
 365          // Make sure we are in the correct taxonomy.
 366          if ( 'post_tag' != $taxonomy ) {
 367              return $terms;
 368          }
 369  
 370          // No terms? Return early!
 371          if ( empty( $terms ) ) {
 372              return $terms;
 373          }
 374  
 375          foreach( $terms as $order => $term ) {
 376              if ( self::get_setting( 'tag-id' ) == $term->term_id ) {
 377                  unset( $terms[ $term->term_id ] );
 378              }
 379          }
 380  
 381          return $terms;
 382      }
 383  
 384      /**
 385       * Register custom setting on the Settings -> Reading screen.
 386       *
 387       * @static
 388       * @access public
 389       * @since Twenty Fourteen 1.0
 390       *
 391       * @return void
 392       */
 393  	public static function register_setting() {
 394          register_setting( 'featured-content', 'featured-content', array( __CLASS__, 'validate_settings' ) );
 395      }
 396  
 397      /**
 398       * Add settings to the Customizer.
 399       *
 400       * @static
 401       * @access public
 402       * @since Twenty Fourteen 1.0
 403       *
 404       * @param WP_Customize_Manager $wp_customize Theme Customizer object.
 405       */
 406  	public static function customize_register( $wp_customize ) {
 407          $wp_customize->add_section( 'featured_content', array(
 408              'title'          => __( 'Featured Content', 'twentyfourteen' ),
 409              'description'    => sprintf( __( 'Use the <a href="%1$s">"featured" tag</a> to feature your posts. You can change this to a tag of your choice; if no posts match the tag, <a href="%2$s">sticky posts</a> will be displayed instead.', 'twentyfourteen' ), admin_url( '/edit.php?tag=featured' ), admin_url( '/edit.php?show_sticky=1' ) ),
 410              'priority'       => 130,
 411              'theme_supports' => 'featured-content',
 412          ) );
 413  
 414          // Add Featured Content settings.
 415          $wp_customize->add_setting( 'featured-content[tag-name]', array(
 416              'default'              => 'featured',
 417              'type'                 => 'option',
 418              'sanitize_js_callback' => array( __CLASS__, 'delete_transient' ),
 419          ) );
 420          $wp_customize->add_setting( 'featured-content[hide-tag]', array(
 421              'default'              => true,
 422              'type'                 => 'option',
 423              'sanitize_js_callback' => array( __CLASS__, 'delete_transient' ),
 424          ) );
 425  
 426          // Add Featured Content controls.
 427          $wp_customize->add_control( 'featured-content[tag-name]', array(
 428              'label'    => __( 'Tag Name', 'twentyfourteen' ),
 429              'section'  => 'featured_content',
 430              'priority' => 20,
 431          ) );
 432          $wp_customize->add_control( 'featured-content[hide-tag]', array(
 433              'label'    => __( 'Don&rsquo;t display tag on front end.', 'twentyfourteen' ),
 434              'section'  => 'featured_content',
 435              'type'     => 'checkbox',
 436              'priority' => 30,
 437          ) );
 438      }
 439  
 440      /**
 441       * Enqueue the tag suggestion script.
 442       *
 443       * @static
 444       * @access public
 445       * @since Twenty Fourteen 1.0
 446       */
 447  	public static function enqueue_scripts() {
 448          wp_enqueue_script( 'featured-content-suggest', get_template_directory_uri() . '/js/featured-content-admin.js', array( 'jquery', 'suggest' ), '20131022', true );
 449      }
 450  
 451      /**
 452       * Get featured content settings.
 453       *
 454       * Get all settings recognized by this module. This function
 455       * will return all settings whether or not they have been stored
 456       * in the database yet. This ensures that all keys are available
 457       * at all times.
 458       *
 459       * In the event that you only require one setting, you may pass
 460       * its name as the first parameter to the function and only that
 461       * value will be returned.
 462       *
 463       * @static
 464       * @access public
 465       * @since Twenty Fourteen 1.0
 466       *
 467       * @param string $key The key of a recognized setting.
 468       * @return mixed Array of all settings by default. A single value if passed as first parameter.
 469       */
 470  	public static function get_setting( $key = 'all' ) {
 471          $saved = (array) get_option( 'featured-content' );
 472  
 473          $defaults = array(
 474              'hide-tag' => 1,
 475              'quantity' => 6,
 476              'tag-id'   => 0,
 477              'tag-name' => 'featured',
 478          );
 479  
 480          $options = wp_parse_args( $saved, $defaults );
 481          $options = array_intersect_key( $options, $defaults );
 482          $options['quantity'] = self::sanitize_quantity( $options['quantity'] );
 483  
 484          if ( 'all' != $key ) {
 485              return isset( $options[ $key ] ) ? $options[ $key ] : false;
 486          }
 487  
 488          return $options;
 489      }
 490  
 491      /**
 492       * Validate featured content settings.
 493       *
 494       * Make sure that all user supplied content is in an expected
 495       * format before saving to the database. This function will also
 496       * delete the transient set in Featured_Content::get_featured_content().
 497       *
 498       * @static
 499       * @access public
 500       * @since Twenty Fourteen 1.0
 501       *
 502       * @param array $input Array of settings input.
 503       * @return array Validated settings output.
 504       */
 505  	public static function validate_settings( $input ) {
 506          $output = array();
 507  
 508          if ( empty( $input['tag-name'] ) ) {
 509              $output['tag-id'] = 0;
 510          } else {
 511              $term = get_term_by( 'name', $input['tag-name'], 'post_tag' );
 512  
 513              if ( $term ) {
 514                  $output['tag-id'] = $term->term_id;
 515              } else {
 516                  $new_tag = wp_create_tag( $input['tag-name'] );
 517  
 518                  if ( ! is_wp_error( $new_tag ) && isset( $new_tag['term_id'] ) ) {
 519                      $output['tag-id'] = $new_tag['term_id'];
 520                  }
 521              }
 522  
 523              $output['tag-name'] = $input['tag-name'];
 524          }
 525  
 526          if ( isset( $input['quantity'] ) ) {
 527              $output['quantity'] = self::sanitize_quantity( $input['quantity'] );
 528          }
 529  
 530          $output['hide-tag'] = isset( $input['hide-tag'] ) && $input['hide-tag'] ? 1 : 0;
 531  
 532          // Delete the featured post ids transient.
 533          self::delete_transient();
 534  
 535          return $output;
 536      }
 537  
 538      /**
 539       * Sanitize quantity of featured posts.
 540       *
 541       * @static
 542       * @access public
 543       * @since Twenty Fourteen 1.0
 544       *
 545       * @param int $input The value to sanitize.
 546       * @return int A number between 1 and FeaturedContent::$max_posts.
 547       */
 548  	public static function sanitize_quantity( $input ) {
 549          $quantity = absint( $input );
 550  
 551          if ( $quantity > self::$max_posts ) {
 552              $quantity = self::$max_posts;
 553          } else if ( 1 > $quantity ) {
 554              $quantity = 1;
 555          }
 556  
 557          return $quantity;
 558      }
 559  
 560  } // Featured_Content
 561  
 562  Featured_Content::setup();