| 1 | <?php |
| 2 | |
| 3 | /** |
| 4 | * Featured Content. |
| 5 | * |
| 6 | * This module will allow users to define a subset of posts |
| 7 | * to be displayed in a theme-designated featured content area. |
| 8 | * |
| 9 | * This feature will only be activated for themes that declare |
| 10 | * that they support it. This can be done by adding code similar |
| 11 | * to the following during the "after_setup_theme" action: |
| 12 | * |
| 13 | * add_theme_support( 'featured-content', array( |
| 14 | * 'featured_content_filter' => 'mytheme_get_featured_content', |
| 15 | * 'description' => 'Describe the featured content area.', |
| 16 | * 'max_posts' => 20, |
| 17 | * ) ); |
| 18 | * |
| 19 | * For maximum compatibility with different methods of posting |
| 20 | * users will designate a featured post tag to associate posts |
| 21 | * to. Since this tag now has special meaning beyond that of a |
| 22 | * normal tags, users will have the ability to hide it from the |
| 23 | * front-end of their site. |
| 24 | */ |
| 25 | class Featured_Content { |
| 26 | |
| 27 | /** |
| 28 | * The maximum number of posts that a featured content |
| 29 | * area can contain. We define a default value here but |
| 30 | * themes can override this by defining a "max_posts" |
| 31 | * entry in the second parameter passed in the call to |
| 32 | * add_theme_support( 'featured-content' ). |
| 33 | * |
| 34 | * @see Featured_Content::init() |
| 35 | */ |
| 36 | public static $max_posts = 15; |
| 37 | |
| 38 | /** |
| 39 | * Instantiate. |
| 40 | * |
| 41 | * All custom functionality will be hooked into the "init" action. |
| 42 | */ |
| 43 | public static function setup() { |
| 44 | add_action( 'init', array( __class__, 'init' ), 30 ); |
| 45 | } |
| 46 | |
| 47 | /** |
| 48 | * Conditionally Hook into WordPress. |
| 49 | * |
| 50 | * Themes must declare that they support this module by adding |
| 51 | * add_theme_support( 'featured-content' ); during after_setup_theme. |
| 52 | * |
| 53 | * If no theme support is found there is no need to hook into |
| 54 | * WordPress. We'll just return early instead. |
| 55 | * |
| 56 | * @uses Featured_Content::$max_posts |
| 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 | // An array of named arguments must be passed as |
| 66 | // the second parameter of add_theme_support(). |
| 67 | if ( ! isset( $theme_support[0] ) ) |
| 68 | return; |
| 69 | |
| 70 | // Return early if "featured_content_filter" has not been defined. |
| 71 | if ( ! isset( $theme_support[0]['featured_content_filter'] ) ) |
| 72 | return; |
| 73 | |
| 74 | $filter = $theme_support[0]['featured_content_filter']; |
| 75 | |
| 76 | // Themes can override the number of max posts. |
| 77 | if ( isset( $theme_support[0]['max_posts'] ) ) |
| 78 | self::$max_posts = absint( $theme_support[0]['max_posts'] ); |
| 79 | |
| 80 | add_filter( $filter, array( __CLASS__, 'get_featured_posts' ) ); |
| 81 | add_action( 'admin_init', array( __CLASS__, 'register_setting' ) ); |
| 82 | add_action( 'save_post', array( __CLASS__, 'delete_transient' ) ); |
| 83 | add_action( 'delete_post_tag', array( __CLASS__, 'delete_post_tag' ) ); |
| 84 | add_action( 'pre_get_posts', array( __CLASS__, 'pre_get_posts' ) ); |
| 85 | |
| 86 | // Hide "featured" tag from the front-end. |
| 87 | if ( self::get_setting( 'hide-tag' ) ) { |
| 88 | add_filter( 'get_terms', array( __CLASS__, 'hide_featured_term' ), 10, 2 ); |
| 89 | add_filter( 'get_the_terms', array( __CLASS__, 'hide_the_featured_term' ), 10, 3 ); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * Get Featured Posts. |
| 95 | * |
| 96 | * This method is not intended to be called directly. |
| 97 | * Theme developers should place a filter directly in |
| 98 | * their theme and then pass its name as a value of the |
| 99 | * "featured_content_filter" key in the array passed as |
| 100 | * the $args parameter during the call to: |
| 101 | * add_theme_support( 'featured-content', $args ). |
| 102 | * |
| 103 | * @uses Featured_Content::get_featured_post_ids() |
| 104 | * |
| 105 | * @return array|bool |
| 106 | */ |
| 107 | public static function get_featured_posts() { |
| 108 | $post_ids = self::get_featured_post_ids(); |
| 109 | |
| 110 | // User has disabled Featured Content. |
| 111 | if ( false === $post_ids ) |
| 112 | return false; |
| 113 | |
| 114 | // No need to query if there is are no featured posts. |
| 115 | if ( empty( $post_ids ) ) |
| 116 | return array(); |
| 117 | |
| 118 | $featured_posts = get_posts( array( |
| 119 | 'include' => $post_ids, |
| 120 | 'posts_per_page' => count( $post_ids ) |
| 121 | ) ); |
| 122 | |
| 123 | return $featured_posts; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Get Featured Post IDs. |
| 128 | * |
| 129 | * This function will return the an array containing the |
| 130 | * post IDs of all featured posts. |
| 131 | * |
| 132 | * Sets the "featured_content_ids" transient. |
| 133 | * |
| 134 | * @return array|false Array of post IDs. false if user has disabled this feature. |
| 135 | */ |
| 136 | public static function get_featured_post_ids() { |
| 137 | $settings = self::get_setting(); |
| 138 | |
| 139 | // Return false if the user has disabled this feature. |
| 140 | $tag = $settings['tag-id']; |
| 141 | if ( empty( $tag ) ) |
| 142 | return false; |
| 143 | |
| 144 | // Return array of cached results if they exist. |
| 145 | $featured_ids = get_transient( 'featured_content_ids' ); |
| 146 | if ( ! empty( $featured_ids ) ) |
| 147 | return array_map( 'absint', (array) $featured_ids ); |
| 148 | |
| 149 | // Query for featured posts. |
| 150 | $featured = get_posts( array( |
| 151 | 'numberposts' => $settings['quantity'], |
| 152 | 'tax_query' => array( |
| 153 | array( |
| 154 | 'field' => 'term_id', |
| 155 | 'taxonomy' => 'post_tag', |
| 156 | 'terms' => $tag, |
| 157 | ), |
| 158 | ), |
| 159 | ) ); |
| 160 | |
| 161 | // Return empty array if no featured content exists. |
| 162 | if ( ! $featured ) |
| 163 | return array(); |
| 164 | |
| 165 | // Ensure correct format before save/return. |
| 166 | $featured_ids = wp_list_pluck( (array) $featured, 'ID' ); |
| 167 | $featured_ids = array_map( 'absint', $featured_ids ); |
| 168 | |
| 169 | set_transient( 'featured_content_ids', $featured_ids ); |
| 170 | |
| 171 | return $featured_ids; |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Delete Transient. |
| 176 | * |
| 177 | * Hooks in the "save_post" action. |
| 178 | * @see Featured_Content::validate_settings(). |
| 179 | */ |
| 180 | public static function delete_transient() { |
| 181 | delete_transient( 'featured_content_ids' ); |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * Exclude featured posts from the blog query when the blog is the front-page. |
| 186 | * |
| 187 | * Filter the home page posts, and remove any featured post ID's from it. Hooked |
| 188 | * onto the 'pre_get_posts' action, this changes the parameters of the query |
| 189 | * before it gets any posts. |
| 190 | * |
| 191 | * @uses Featured_Content::get_featured_post_ids(); |
| 192 | * @param WP_Query $query |
| 193 | * @return WP_Query Possibly modified WP_query |
| 194 | */ |
| 195 | public static function pre_get_posts( $query = false ) { |
| 196 | |
| 197 | // Bail if not home, not a query, not main query. |
| 198 | if ( ! is_home() || ! is_a( $query, 'WP_Query' ) || ! $query->is_main_query() ) |
| 199 | return; |
| 200 | |
| 201 | $page_on_front = get_option( 'page_on_front' ); |
| 202 | |
| 203 | // Bail if the blog page is not the front page. |
| 204 | if ( ! empty( $page_on_front ) ) |
| 205 | return; |
| 206 | |
| 207 | $featured = self::get_featured_post_ids(); |
| 208 | |
| 209 | // Bail if no featured posts. |
| 210 | if ( ! $featured ) |
| 211 | return; |
| 212 | |
| 213 | // We need to respect post ids already in the blacklist. |
| 214 | $post__not_in = $query->get( 'post__not_in' ); |
| 215 | |
| 216 | if ( ! empty( $post__not_in ) ) { |
| 217 | $featured = array_merge( (array) $post__not_in, $featured ); |
| 218 | $featured = array_unique( $featured ); |
| 219 | } |
| 220 | |
| 221 | $query->set( 'post__not_in', $featured ); |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Reset tag option when the saved tag is deleted. |
| 226 | * |
| 227 | * It's important to mention that the transient needs |
| 228 | * to be deleted too. While it may not be obvious by |
| 229 | * looking at the function alone, the transient is |
| 230 | * deleted by Featured_Content::validate_settings(). |
| 231 | * |
| 232 | * @param int $tag_id the term_id of the tag that has been deleted. |
| 233 | * |
| 234 | * Hooks in the "delete_post_tag" action. |
| 235 | * @see Featured_Content::validate_settings(). |
| 236 | */ |
| 237 | public static function delete_post_tag( $tag_id ) { |
| 238 | $settings = self::get_setting(); |
| 239 | |
| 240 | if ( empty( $settings['tag-id'] ) ) |
| 241 | return; |
| 242 | |
| 243 | if ( $tag_id != $settings['tag-id'] ) |
| 244 | return; |
| 245 | |
| 246 | $settings['tag-id'] = 0; |
| 247 | $settings = self::validate_settings( $settings ); |
| 248 | update_option( 'featured-content', $settings ); |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * Hide featured tag from displaying when global terms are queried from the front-end. |
| 253 | * |
| 254 | * Hooks into the "get_terms" filter. |
| 255 | * |
| 256 | * @param array $terms A list of term objects. This is the return value of get_terms(). |
| 257 | * @param array $taxonomies An array of taxonomy slugs. |
| 258 | * |
| 259 | * @uses Featured_Content::get_setting() |
| 260 | */ |
| 261 | public static function hide_featured_term( $terms, $taxonomies ) { |
| 262 | |
| 263 | // This filter is only appropriate on the front-end. |
| 264 | if ( is_admin() ) |
| 265 | return $terms; |
| 266 | |
| 267 | // We only want to hide the featured tag. |
| 268 | if ( ! in_array( 'post_tag', $taxonomies ) ) |
| 269 | return $terms; |
| 270 | |
| 271 | // Bail if no terms were returned. |
| 272 | if ( empty( $terms ) ) |
| 273 | return $terms; |
| 274 | |
| 275 | foreach( $terms as $order => $term ) { |
| 276 | if ( self::get_setting( 'tag-id' ) == $term->term_id && 'post_tag' == $term->taxonomy ) |
| 277 | unset( $terms[$order] ); |
| 278 | } |
| 279 | |
| 280 | return $terms; |
| 281 | } |
| 282 | |
| 283 | /** |
| 284 | * Hide featured tag from displaying when terms associated with |
| 285 | * a post object are queried from the front-end. |
| 286 | * |
| 287 | * Hooks into the "get_the_terms" filter. |
| 288 | * |
| 289 | * @param array $terms A list of term objects. This is the return value of get_the_terms(). |
| 290 | * @param int $id The ID field for the post object that terms are associated with. |
| 291 | * @param array $taxonomy An array of taxonomy slugs. |
| 292 | * |
| 293 | * @uses Featured_Content::get_setting() |
| 294 | */ |
| 295 | public static function hide_the_featured_term( $terms, $id, $taxonomy ) { |
| 296 | |
| 297 | // This filter is only appropriate on the front-end. |
| 298 | if ( is_admin() ) |
| 299 | return $terms; |
| 300 | |
| 301 | // Make sure we are in the correct taxonomy. |
| 302 | if ( ! 'post_tag' == $taxonomy ) |
| 303 | return $terms; |
| 304 | |
| 305 | // No terms? Return early! |
| 306 | if ( empty( $terms ) ) |
| 307 | return $terms; |
| 308 | |
| 309 | foreach( $terms as $order => $term ) { |
| 310 | if ( self::get_setting( 'tag-id' ) == $term->term_id ) |
| 311 | unset( $terms[$term->term_id] ); |
| 312 | } |
| 313 | |
| 314 | return $terms; |
| 315 | } |
| 316 | |
| 317 | /** |
| 318 | * Register custom setting on the Settings -> Reading screen. |
| 319 | * |
| 320 | * @uses Featured_Content::render_form() |
| 321 | * @uses Featured_Content::validate_settings() |
| 322 | */ |
| 323 | public static function register_setting() { |
| 324 | add_settings_field( 'featured-content', __( 'Featured content', 'twentyfourteen' ), array( __class__, 'render_form' ), 'reading' ); |
| 325 | register_setting( 'reading', 'featured-content', array( __class__, 'validate_settings' ) ); |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * Renders all form fields on the Settings -> Reading screen. |
| 330 | */ |
| 331 | public static function render_form() { |
| 332 | $settings = self::get_setting(); |
| 333 | |
| 334 | $tag_name = ''; |
| 335 | if ( ! empty( $settings['tag-id'] ) ) { |
| 336 | $tag = get_term( $settings['tag-id'], 'post_tag' ); |
| 337 | if ( ! is_wp_error( $tag ) && isset( $tag->name ) ) |
| 338 | $tag_name = $tag->name; |
| 339 | } |
| 340 | ?> |
| 341 | <div id="featured-content-ui"> |
| 342 | <p> |
| 343 | <label for="featured-content-tag-name"><?php echo _e( 'Tag name:', 'twentyfourteen' ); ?></label> |
| 344 | <input type="text" id="featured-content-tag-name" name="featured-content[tag-name]" value="<?php echo esc_attr( $tag_name ); ?>"> |
| 345 | <input type="hidden" id="featured-content-tag-id" name="featured-content[tag-id]" value="<?php echo esc_attr( $settings['tag-id'] ); ?>"> |
| 346 | </p> |
| 347 | <p> |
| 348 | <label for="featured-content-quantity"><?php _e( 'Number of posts:', 'twentyfourteen' ); ?></label> |
| 349 | <input class="small-text" type="number" step="1" min="1" max="<?php echo esc_attr( self::$max_posts ); ?>" id="featured-content-quantity" name="featured-content[quantity]" value="<?php echo esc_attr( $settings['quantity'] ); ?>"> |
| 350 | </p> |
| 351 | <p> |
| 352 | <input type="checkbox" id="featured-content-hide-tag" name="featured-content[hide-tag]" <?php checked( $settings['hide-tag'], 1 ); ?>"> |
| 353 | <label for="featured-content-hide-tag"><?php _e( 'Hide tag from displaying in post meta and tag clouds.', 'twentyfourteen' ); ?></label> |
| 354 | </p> |
| 355 | </div> |
| 356 | <?php |
| 357 | } |
| 358 | |
| 359 | /** |
| 360 | * Get Settings. |
| 361 | * |
| 362 | * Get all settings recognized by this module. This |
| 363 | * function will return all settings whether or not |
| 364 | * they have been stored in the database yet. This |
| 365 | * ensures that all keys are available at all times. |
| 366 | * |
| 367 | * In the event that you only require one setting, you |
| 368 | * may pass its name as the first parameter to the function |
| 369 | * and only that value will be returned. |
| 370 | * |
| 371 | * @uses Featured_Content::self::sanitize_quantity() |
| 372 | * |
| 373 | * @param string $key The key of a recognized setting. |
| 374 | * @return mixed Array of all settings by default. A single value if passed as first parameter. |
| 375 | */ |
| 376 | public static function get_setting( $key = 'all' ) { |
| 377 | $saved = (array) get_option( 'featured-content' ); |
| 378 | |
| 379 | $defaults = array( |
| 380 | 'hide-tag' => 1, |
| 381 | 'quantity' => 5, |
| 382 | 'tag-id' => 0, |
| 383 | ); |
| 384 | |
| 385 | $options = wp_parse_args( $saved, $defaults ); |
| 386 | $options = array_intersect_key( $options, $defaults ); |
| 387 | $options['quantity'] = self::sanitize_quantity( $options['quantity'] ); |
| 388 | |
| 389 | if ( 'all' != $key ) { |
| 390 | if ( isset( $options[$key] ) ) |
| 391 | return $options[$key]; |
| 392 | else |
| 393 | return false; |
| 394 | } |
| 395 | |
| 396 | return $options; |
| 397 | } |
| 398 | |
| 399 | /** |
| 400 | * Validate Settings. |
| 401 | * |
| 402 | * Make sure that all user supplied content is in an |
| 403 | * expected format before saving to the database. This |
| 404 | * function will also delete the transient set in |
| 405 | * Featured_Content::get_featured_content(). |
| 406 | * |
| 407 | * @uses Featured_Content::self::sanitize_quantity() |
| 408 | * @uses Featured_Content::self::delete_transient() |
| 409 | */ |
| 410 | public static function validate_settings( $input ) { |
| 411 | $output = array(); |
| 412 | |
| 413 | if ( isset( $input['tag-id'] ) ) |
| 414 | $output['tag-id'] = absint( $input['tag-id'] ); |
| 415 | |
| 416 | if ( isset( $input['tag-name'] ) && ! empty( $input['tag-name'] ) ) { |
| 417 | $new_tag = wp_create_tag( $input['tag-name'] ); |
| 418 | if ( ! is_wp_error( $new_tag ) && isset( $new_tag['term_id'] ) ) |
| 419 | $tag = get_term( $new_tag['term_id'], 'post_tag' ); |
| 420 | if ( isset( $tag->term_id ) ) |
| 421 | $output['tag-id'] = $tag->term_id; |
| 422 | } else { |
| 423 | unset( $output['tag-id'] ); |
| 424 | } |
| 425 | |
| 426 | if ( isset( $input['quantity'] ) ) |
| 427 | $output['quantity'] = self::sanitize_quantity( $input['quantity'] ); |
| 428 | |
| 429 | $output['hide-tag'] = ( isset( $input['hide-tag'] ) ) ? 1 : 0; |
| 430 | |
| 431 | self::delete_transient(); |
| 432 | |
| 433 | return $output; |
| 434 | } |
| 435 | |
| 436 | /** |
| 437 | * Sanitize Quantity |
| 438 | * |
| 439 | * @param int $input The value to sanitize. |
| 440 | * @output int A number between 1 and FeaturedContent::$max_posts. |
| 441 | * |
| 442 | * @uses Featured_Content::$max_posts |
| 443 | */ |
| 444 | public static function sanitize_quantity( $input ) { |
| 445 | $quantity = absint( $input ); |
| 446 | |
| 447 | if ( $quantity > self::$max_posts ) |
| 448 | $quantity = self::$max_posts; |
| 449 | else if ( 1 > $quantity ) |
| 450 | $quantity = 1; |
| 451 | |
| 452 | return $quantity; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | Featured_Content::setup(); |