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   1  <?php
   2  /**
   3   * Widget API: WP_Widget base class
   4   *
   5   * @package WordPress
   6   * @subpackage Widgets
   7   * @since 4.4.0
   8   */
   9  
  10  /**
  11   * Core base class extended to register widgets.
  12   *
  13   * This class must be extended for each widget, and WP_Widget::widget() must be overridden.
  14   *
  15   * If adding widget options, WP_Widget::update() and WP_Widget::form() should also be overridden.
  16   *
  17   * @since 2.8.0
  18   * @since 4.4.0 Moved to its own file from wp-includes/widgets.php
  19   */
  20  class WP_Widget {
  21  
  22      /**
  23       * Root ID for all widgets of this type.
  24       *
  25       * @since 2.8.0
  26       * @var mixed|string
  27       */
  28      public $id_base;
  29  
  30      /**
  31       * Name for this widget type.
  32       *
  33       * @since 2.8.0
  34       * @var string
  35       */
  36      public $name;
  37  
  38      /**
  39       * Option name for this widget type.
  40       *
  41       * @since 2.8.0
  42       * @var string
  43       */
  44      public $option_name;
  45  
  46      /**
  47       * Alt option name for this widget type.
  48       *
  49       * @since 2.8.0
  50       * @var string
  51       */
  52      public $alt_option_name;
  53  
  54      /**
  55       * Option array passed to wp_register_sidebar_widget().
  56       *
  57       * @since 2.8.0
  58       * @var array
  59       */
  60      public $widget_options;
  61  
  62      /**
  63       * Option array passed to wp_register_widget_control().
  64       *
  65       * @since 2.8.0
  66       * @var array
  67       */
  68      public $control_options;
  69  
  70      /**
  71       * Unique ID number of the current instance.
  72       *
  73       * @since 2.8.0
  74       * @var bool|int
  75       */
  76      public $number = false;
  77  
  78      /**
  79       * Unique ID string of the current instance (id_base-number).
  80       *
  81       * @since 2.8.0
  82       * @var bool|string
  83       */
  84      public $id = false;
  85  
  86      /**
  87       * Whether the widget data has been updated.
  88       *
  89       * Set to true when the data is updated after a POST submit - ensures it does
  90       * not happen twice.
  91       *
  92       * @since 2.8.0
  93       * @var bool
  94       */
  95      public $updated = false;
  96  
  97      //
  98      // Member functions that must be overridden by subclasses.
  99      //
 100  
 101      /**
 102       * Echoes the widget content.
 103       *
 104       * Subclasses should override this function to generate their widget code.
 105       *
 106       * @since 2.8.0
 107       *
 108       * @param array $args     Display arguments including 'before_title', 'after_title',
 109       *                        'before_widget', and 'after_widget'.
 110       * @param array $instance The settings for the particular instance of the widget.
 111       */
 112  	public function widget( $args, $instance ) {
 113          die( 'function WP_Widget::widget() must be overridden in a subclass.' );
 114      }
 115  
 116      /**
 117       * Updates a particular instance of a widget.
 118       *
 119       * This function should check that `$new_instance` is set correctly. The newly-calculated
 120       * value of `$instance` should be returned. If false is returned, the instance won't be
 121       * saved/updated.
 122       *
 123       * @since 2.8.0
 124       *
 125       * @param array $new_instance New settings for this instance as input by the user via
 126       *                            WP_Widget::form().
 127       * @param array $old_instance Old settings for this instance.
 128       * @return array Settings to save or bool false to cancel saving.
 129       */
 130  	public function update( $new_instance, $old_instance ) {
 131          return $new_instance;
 132      }
 133  
 134      /**
 135       * Outputs the settings update form.
 136       *
 137       * @since 2.8.0
 138       *
 139       * @param array $instance Current settings.
 140       * @return string Default return is 'noform'.
 141       */
 142  	public function form( $instance ) {
 143          echo '<p class="no-options-widget">' . __( 'There are no options for this widget.' ) . '</p>';
 144          return 'noform';
 145      }
 146  
 147      // Functions you'll need to call.
 148  
 149      /**
 150       * PHP5 constructor.
 151       *
 152       * @since 2.8.0
 153       *
 154       * @param string $id_base         Optional. Base ID for the widget, lowercase and unique. If left empty,
 155       *                                a portion of the widget's class name will be used. Has to be unique.
 156       * @param string $name            Name for the widget displayed on the configuration page.
 157       * @param array  $widget_options  Optional. Widget options. See wp_register_sidebar_widget() for
 158       *                                information on accepted arguments. Default empty array.
 159       * @param array  $control_options Optional. Widget control options. See wp_register_widget_control() for
 160       *                                information on accepted arguments. Default empty array.
 161       */
 162  	public function __construct( $id_base, $name, $widget_options = array(), $control_options = array() ) {
 163          $this->id_base         = empty( $id_base ) ? preg_replace( '/(wp_)?widget_/', '', strtolower( get_class( $this ) ) ) : strtolower( $id_base );
 164          $this->name            = $name;
 165          $this->option_name     = 'widget_' . $this->id_base;
 166          $this->widget_options  = wp_parse_args(
 167              $widget_options,
 168              array(
 169                  'classname'                   => $this->option_name,
 170                  'customize_selective_refresh' => false,
 171              )
 172          );
 173          $this->control_options = wp_parse_args( $control_options, array( 'id_base' => $this->id_base ) );
 174      }
 175  
 176      /**
 177       * PHP4 constructor.
 178       *
 179       * @since 2.8.0
 180       * @deprecated 4.3.0 Use __construct() instead.
 181       *
 182       * @see WP_Widget::__construct()
 183       *
 184       * @param string $id_base         Optional. Base ID for the widget, lowercase and unique. If left empty,
 185       *                                a portion of the widget's class name will be used. Has to be unique.
 186       * @param string $name            Name for the widget displayed on the configuration page.
 187       * @param array  $widget_options  Optional. Widget options. See wp_register_sidebar_widget() for
 188       *                                information on accepted arguments. Default empty array.
 189       * @param array  $control_options Optional. Widget control options. See wp_register_widget_control() for
 190       *                                information on accepted arguments. Default empty array.
 191       */
 192  	public function WP_Widget( $id_base, $name, $widget_options = array(), $control_options = array() ) {
 193          _deprecated_constructor( 'WP_Widget', '4.3.0', get_class( $this ) );
 194          WP_Widget::__construct( $id_base, $name, $widget_options, $control_options );
 195      }
 196  
 197      /**
 198       * Constructs name attributes for use in form() fields
 199       *
 200       * This function should be used in form() methods to create name attributes for fields
 201       * to be saved by update()
 202       *
 203       * @since 2.8.0
 204       * @since 4.4.0 Array format field names are now accepted.
 205       *
 206       * @param string $field_name Field name
 207       * @return string Name attribute for $field_name
 208       */
 209  	public function get_field_name( $field_name ) {
 210          $pos = strpos( $field_name, '[' );
 211          if ( false === $pos ) {
 212              return 'widget-' . $this->id_base . '[' . $this->number . '][' . $field_name . ']';
 213          } else {
 214              return 'widget-' . $this->id_base . '[' . $this->number . '][' . substr_replace( $field_name, '][', $pos, strlen( '[' ) );
 215          }
 216      }
 217  
 218      /**
 219       * Constructs id attributes for use in WP_Widget::form() fields.
 220       *
 221       * This function should be used in form() methods to create id attributes
 222       * for fields to be saved by WP_Widget::update().
 223       *
 224       * @since 2.8.0
 225       * @since 4.4.0 Array format field IDs are now accepted.
 226       *
 227       * @param string $field_name Field name.
 228       * @return string ID attribute for `$field_name`.
 229       */
 230  	public function get_field_id( $field_name ) {
 231          return 'widget-' . $this->id_base . '-' . $this->number . '-' . trim( str_replace( array( '[]', '[', ']' ), array( '', '-', '' ), $field_name ), '-' );
 232      }
 233  
 234      /**
 235       * Register all widget instances of this widget class.
 236       *
 237       * @since 2.8.0
 238       */
 239  	public function _register() {
 240          $settings = $this->get_settings();
 241          $empty    = true;
 242  
 243          // When $settings is an array-like object, get an intrinsic array for use with array_keys().
 244          if ( $settings instanceof ArrayObject || $settings instanceof ArrayIterator ) {
 245              $settings = $settings->getArrayCopy();
 246          }
 247  
 248          if ( is_array( $settings ) ) {
 249              foreach ( array_keys( $settings ) as $number ) {
 250                  if ( is_numeric( $number ) ) {
 251                      $this->_set( $number );
 252                      $this->_register_one( $number );
 253                      $empty = false;
 254                  }
 255              }
 256          }
 257  
 258          if ( $empty ) {
 259              // If there are none, we register the widget's existence with a generic template.
 260              $this->_set( 1 );
 261              $this->_register_one();
 262          }
 263      }
 264  
 265      /**
 266       * Sets the internal order number for the widget instance.
 267       *
 268       * @since 2.8.0
 269       *
 270       * @param int $number The unique order number of this widget instance compared to other
 271       *                    instances of the same class.
 272       */
 273  	public function _set( $number ) {
 274          $this->number = $number;
 275          $this->id     = $this->id_base . '-' . $number;
 276      }
 277  
 278      /**
 279       * Retrieves the widget display callback.
 280       *
 281       * @since 2.8.0
 282       *
 283       * @return callable Display callback.
 284       */
 285  	public function _get_display_callback() {
 286          return array( $this, 'display_callback' );
 287      }
 288  
 289      /**
 290       * Retrieves the widget update callback.
 291       *
 292       * @since 2.8.0
 293       *
 294       * @return callable Update callback.
 295       */
 296  	public function _get_update_callback() {
 297          return array( $this, 'update_callback' );
 298      }
 299  
 300      /**
 301       * Retrieves the form callback.
 302       *
 303       * @since 2.8.0
 304       *
 305       * @return callable Form callback.
 306       */
 307  	public function _get_form_callback() {
 308          return array( $this, 'form_callback' );
 309      }
 310  
 311      /**
 312       * Determines whether the current request is inside the Customizer preview.
 313       *
 314       * If true -- the current request is inside the Customizer preview, then
 315       * the object cache gets suspended and widgets should check this to decide
 316       * whether they should store anything persistently to the object cache,
 317       * to transients, or anywhere else.
 318       *
 319       * @since 3.9.0
 320       *
 321       * @global WP_Customize_Manager $wp_customize
 322       *
 323       * @return bool True if within the Customizer preview, false if not.
 324       */
 325  	public function is_preview() {
 326          global $wp_customize;
 327          return ( isset( $wp_customize ) && $wp_customize->is_preview() );
 328      }
 329  
 330      /**
 331       * Generates the actual widget content (Do NOT override).
 332       *
 333       * Finds the instance and calls WP_Widget::widget().
 334       *
 335       * @since 2.8.0
 336       *
 337       * @param array     $args        Display arguments. See WP_Widget::widget() for information
 338       *                               on accepted arguments.
 339       * @param int|array $widget_args {
 340       *     Optional. Internal order number of the widget instance, or array of multi-widget arguments.
 341       *     Default 1.
 342       *
 343       *     @type int $number Number increment used for multiples of the same widget.
 344       * }
 345       */
 346  	public function display_callback( $args, $widget_args = 1 ) {
 347          if ( is_numeric( $widget_args ) ) {
 348              $widget_args = array( 'number' => $widget_args );
 349          }
 350  
 351          $widget_args = wp_parse_args( $widget_args, array( 'number' => -1 ) );
 352          $this->_set( $widget_args['number'] );
 353          $instances = $this->get_settings();
 354  
 355          if ( array_key_exists( $this->number, $instances ) ) {
 356              $instance = $instances[ $this->number ];
 357  
 358              /**
 359               * Filters the settings for a particular widget instance.
 360               *
 361               * Returning false will effectively short-circuit display of the widget.
 362               *
 363               * @since 2.8.0
 364               *
 365               * @param array     $instance The current widget instance's settings.
 366               * @param WP_Widget $this     The current widget instance.
 367               * @param array     $args     An array of default widget arguments.
 368               */
 369              $instance = apply_filters( 'widget_display_callback', $instance, $this, $args );
 370  
 371              if ( false === $instance ) {
 372                  return;
 373              }
 374  
 375              $was_cache_addition_suspended = wp_suspend_cache_addition();
 376              if ( $this->is_preview() && ! $was_cache_addition_suspended ) {
 377                  wp_suspend_cache_addition( true );
 378              }
 379  
 380              $this->widget( $args, $instance );
 381  
 382              if ( $this->is_preview() ) {
 383                  wp_suspend_cache_addition( $was_cache_addition_suspended );
 384              }
 385          }
 386      }
 387  
 388      /**
 389       * Handles changed settings (Do NOT override).
 390       *
 391       * @since 2.8.0
 392       *
 393       * @global array $wp_registered_widgets
 394       *
 395       * @param int $deprecated Not used.
 396       */
 397  	public function update_callback( $deprecated = 1 ) {
 398          global $wp_registered_widgets;
 399  
 400          $all_instances = $this->get_settings();
 401  
 402          // We need to update the data.
 403          if ( $this->updated ) {
 404              return;
 405          }
 406  
 407          if ( isset( $_POST['delete_widget'] ) && $_POST['delete_widget'] ) {
 408              // Delete the settings for this instance of the widget.
 409              if ( isset( $_POST['the-widget-id'] ) ) {
 410                  $del_id = $_POST['the-widget-id'];
 411              } else {
 412                  return;
 413              }
 414  
 415              if ( isset( $wp_registered_widgets[ $del_id ]['params'][0]['number'] ) ) {
 416                  $number = $wp_registered_widgets[ $del_id ]['params'][0]['number'];
 417  
 418                  if ( $this->id_base . '-' . $number == $del_id ) {
 419                      unset( $all_instances[ $number ] );
 420                  }
 421              }
 422          } else {
 423              if ( isset( $_POST[ 'widget-' . $this->id_base ] ) && is_array( $_POST[ 'widget-' . $this->id_base ] ) ) {
 424                  $settings = $_POST[ 'widget-' . $this->id_base ];
 425              } elseif ( isset( $_POST['id_base'] ) && $_POST['id_base'] == $this->id_base ) {
 426                  $num      = $_POST['multi_number'] ? (int) $_POST['multi_number'] : (int) $_POST['widget_number'];
 427                  $settings = array( $num => array() );
 428              } else {
 429                  return;
 430              }
 431  
 432              foreach ( $settings as $number => $new_instance ) {
 433                  $new_instance = stripslashes_deep( $new_instance );
 434                  $this->_set( $number );
 435  
 436                  $old_instance = isset( $all_instances[ $number ] ) ? $all_instances[ $number ] : array();
 437  
 438                  $was_cache_addition_suspended = wp_suspend_cache_addition();
 439                  if ( $this->is_preview() && ! $was_cache_addition_suspended ) {
 440                      wp_suspend_cache_addition( true );
 441                  }
 442  
 443                  $instance = $this->update( $new_instance, $old_instance );
 444  
 445                  if ( $this->is_preview() ) {
 446                      wp_suspend_cache_addition( $was_cache_addition_suspended );
 447                  }
 448  
 449                  /**
 450                   * Filters a widget's settings before saving.
 451                   *
 452                   * Returning false will effectively short-circuit the widget's ability
 453                   * to update settings.
 454                   *
 455                   * @since 2.8.0
 456                   *
 457                   * @param array     $instance     The current widget instance's settings.
 458                   * @param array     $new_instance Array of new widget settings.
 459                   * @param array     $old_instance Array of old widget settings.
 460                   * @param WP_Widget $this         The current widget instance.
 461                   */
 462                  $instance = apply_filters( 'widget_update_callback', $instance, $new_instance, $old_instance, $this );
 463                  if ( false !== $instance ) {
 464                      $all_instances[ $number ] = $instance;
 465                  }
 466  
 467                  break; // Run only once.
 468              }
 469          }
 470  
 471          $this->save_settings( $all_instances );
 472          $this->updated = true;
 473      }
 474  
 475      /**
 476       * Generates the widget control form (Do NOT override).
 477       *
 478       * @since 2.8.0
 479       *
 480       * @param int|array $widget_args {
 481       *     Optional. Internal order number of the widget instance, or array of multi-widget arguments.
 482       *     Default 1.
 483       *
 484       *     @type int $number Number increment used for multiples of the same widget.
 485       * }
 486       * @return string|null
 487       */
 488  	public function form_callback( $widget_args = 1 ) {
 489          if ( is_numeric( $widget_args ) ) {
 490              $widget_args = array( 'number' => $widget_args );
 491          }
 492  
 493          $widget_args   = wp_parse_args( $widget_args, array( 'number' => -1 ) );
 494          $all_instances = $this->get_settings();
 495  
 496          if ( -1 == $widget_args['number'] ) {
 497              // We echo out a form where 'number' can be set later.
 498              $this->_set( '__i__' );
 499              $instance = array();
 500          } else {
 501              $this->_set( $widget_args['number'] );
 502              $instance = $all_instances[ $widget_args['number'] ];
 503          }
 504  
 505          /**
 506           * Filters the widget instance's settings before displaying the control form.
 507           *
 508           * Returning false effectively short-circuits display of the control form.
 509           *
 510           * @since 2.8.0
 511           *
 512           * @param array     $instance The current widget instance's settings.
 513           * @param WP_Widget $this     The current widget instance.
 514           */
 515          $instance = apply_filters( 'widget_form_callback', $instance, $this );
 516  
 517          $return = null;
 518          if ( false !== $instance ) {
 519              $return = $this->form( $instance );
 520  
 521              /**
 522               * Fires at the end of the widget control form.
 523               *
 524               * Use this hook to add extra fields to the widget form. The hook
 525               * is only fired if the value passed to the 'widget_form_callback'
 526               * hook is not false.
 527               *
 528               * Note: If the widget has no form, the text echoed from the default
 529               * form method can be hidden using CSS.
 530               *
 531               * @since 2.8.0
 532               *
 533               * @param WP_Widget $this     The widget instance (passed by reference).
 534               * @param null      $return   Return null if new fields are added.
 535               * @param array     $instance An array of the widget's settings.
 536               */
 537              do_action_ref_array( 'in_widget_form', array( &$this, &$return, $instance ) );
 538          }
 539          return $return;
 540      }
 541  
 542      /**
 543       * Registers an instance of the widget class.
 544       *
 545       * @since 2.8.0
 546       *
 547       * @param integer $number Optional. The unique order number of this widget instance
 548       *                        compared to other instances of the same class. Default -1.
 549       */
 550  	public function _register_one( $number = -1 ) {
 551          wp_register_sidebar_widget( $this->id, $this->name, $this->_get_display_callback(), $this->widget_options, array( 'number' => $number ) );
 552          _register_widget_update_callback( $this->id_base, $this->_get_update_callback(), $this->control_options, array( 'number' => -1 ) );
 553          _register_widget_form_callback( $this->id, $this->name, $this->_get_form_callback(), $this->control_options, array( 'number' => $number ) );
 554      }
 555  
 556      /**
 557       * Saves the settings for all instances of the widget class.
 558       *
 559       * @since 2.8.0
 560       *
 561       * @param array $settings Multi-dimensional array of widget instance settings.
 562       */
 563  	public function save_settings( $settings ) {
 564          $settings['_multiwidget'] = 1;
 565          update_option( $this->option_name, $settings );
 566      }
 567  
 568      /**
 569       * Retrieves the settings for all instances of the widget class.
 570       *
 571       * @since 2.8.0
 572       *
 573       * @return array Multi-dimensional array of widget instance settings.
 574       */
 575  	public function get_settings() {
 576  
 577          $settings = get_option( $this->option_name );
 578  
 579          if ( false === $settings ) {
 580              if ( isset( $this->alt_option_name ) ) {
 581                  $settings = get_option( $this->alt_option_name );
 582              } else {
 583                  // Save an option so it can be autoloaded next time.
 584                  $this->save_settings( array() );
 585              }
 586          }
 587  
 588          if ( ! is_array( $settings ) && ! ( $settings instanceof ArrayObject || $settings instanceof ArrayIterator ) ) {
 589              $settings = array();
 590          }
 591  
 592          if ( ! empty( $settings ) && ! isset( $settings['_multiwidget'] ) ) {
 593              // Old format, convert if single widget.
 594              $settings = wp_convert_widget_settings( $this->id_base, $this->option_name, $settings );
 595          }
 596  
 597          unset( $settings['_multiwidget'], $settings['__i__'] );
 598          return $settings;
 599      }
 600  }