+/**
+ * This class must be extended for each widget and WP_Widget::widget(), WP_Widget::update()
+ * and WP_Widget::form() need to be over-ridden.
+ *
+ * @package WordPress
+ * @subpackage Widgets
+ * @since 2.8
+ */
+class WP_Widget {
+
+ var $id_base; // Root id for all widgets of this type.
+ var $name; // Name for this widget type.
+ var $widget_options; // Option array passed to wp_register_sidebar_widget()
+ var $control_options; // Option array passed to wp_register_widget_control()
+
+ var $number = false; // Unique ID number of the current instance.
+ var $id = false; // Unique ID string of the current instance (id_base-number)
+ var $updated = false; // Set true when we update the data after a POST submit - makes sure we don't do it twice.
+
+ // Member functions that you must over-ride.
+
+ /** Echo the widget content.
+ *
+ * Subclasses should over-ride this function to generate their widget code.
+ *
+ * @param array $args Display arguments including before_title, after_title, before_widget, and after_widget.
+ * @param array $instance The settings for the particular instance of the widget
+ */
+ function widget($args, $instance) {
+ die('function WP_Widget::widget() must be over-ridden in a sub-class.');
+ }
+
+ /** Update a particular instance.
+ *
+ * This function should check that $new_instance is set correctly.
+ * The newly calculated value of $instance should be returned.
+ * If "false" is returned, the instance won't be saved/updated.
+ *
+ * @param array $new_instance New settings for this instance as input by the user via form()
+ * @param array $old_instance Old settings for this instance
+ * @return array Settings to save or bool false to cancel saving
+ */
+ function update($new_instance, $old_instance) {
+ return $new_instance;
+ }
+
+ /** Echo the settings update form
+ *
+ * @param array $instance Current settings
+ */
+ function form($instance) {
+ echo '<p class="no-options-widget">' . __('There are no options for this widget.') . '</p>';
+ return 'noform';
+ }
+
+ // Functions you'll need to call.
+
+ /**
+ * PHP5 constructor
+ *
+ * @param string $id_base Optional Base ID for the widget, lower case,
+ * if left empty a portion of the widget's class name will be used. Has to be unique.
+ * @param string $name Name for the widget displayed on the configuration page.
+ * @param array $widget_options Optional Passed to wp_register_sidebar_widget()
+ * - description: shown on the configuration page
+ * - classname
+ * @param array $control_options Optional Passed to wp_register_widget_control()
+ * - width: required if more than 250px
+ * - height: currently not used but may be needed in the future
+ */
+ function __construct( $id_base, $name, $widget_options = array(), $control_options = array() ) {
+ $this->id_base = empty($id_base) ? preg_replace( '/(wp_)?widget_/', '', strtolower(get_class($this)) ) : strtolower($id_base);
+ $this->name = $name;
+ $this->option_name = 'widget_' . $this->id_base;
+ $this->widget_options = wp_parse_args( $widget_options, array('classname' => $this->option_name) );
+ $this->control_options = wp_parse_args( $control_options, array('id_base' => $this->id_base) );
+ }
+
+ /**
+ * PHP4 constructor
+ */
+ function WP_Widget( $id_base, $name, $widget_options = array(), $control_options = array() ) {
+ WP_Widget::__construct( $id_base, $name, $widget_options, $control_options );
+ }
+
+ /**
+ * Constructs name attributes for use in form() fields
+ *
+ * This function should be used in form() methods to create name attributes for fields to be saved by update()
+ *
+ * @param string $field_name Field name
+ * @return string Name attribute for $field_name
+ */
+ function get_field_name($field_name) {
+ return 'widget-' . $this->id_base . '[' . $this->number . '][' . $field_name . ']';
+ }
+
+ /**
+ * Constructs id attributes for use in form() fields
+ *
+ * This function should be used in form() methods to create id attributes for fields to be saved by update()
+ *
+ * @param string $field_name Field name
+ * @return string ID attribute for $field_name
+ */
+ function get_field_id($field_name) {
+ return 'widget-' . $this->id_base . '-' . $this->number . '-' . $field_name;
+ }
+
+ // Private Functions. Don't worry about these.
+
+ function _register() {
+ $settings = $this->get_settings();
+ $empty = true;
+
+ if ( is_array($settings) ) {
+ foreach ( array_keys($settings) as $number ) {
+ if ( is_numeric($number) ) {
+ $this->_set($number);
+ $this->_register_one($number);
+ $empty = false;
+ }
+ }
+ }
+
+ if ( $empty ) {
+ // If there are none, we register the widget's existence with a
+ // generic template
+ $this->_set(1);
+ $this->_register_one();
+ }
+ }
+
+ function _set($number) {
+ $this->number = $number;
+ $this->id = $this->id_base . '-' . $number;
+ }
+
+ function _get_display_callback() {
+ return array($this, 'display_callback');
+ }
+
+ function _get_update_callback() {
+ return array($this, 'update_callback');
+ }
+
+ function _get_form_callback() {
+ return array($this, 'form_callback');
+ }
+
+ /** Generate the actual widget content.
+ * Just finds the instance and calls widget().
+ * Do NOT over-ride this function. */
+ function display_callback( $args, $widget_args = 1 ) {
+ if ( is_numeric($widget_args) )
+ $widget_args = array( 'number' => $widget_args );
+
+ $widget_args = wp_parse_args( $widget_args, array( 'number' => -1 ) );
+ $this->_set( $widget_args['number'] );
+ $instance = $this->get_settings();
+
+ if ( array_key_exists( $this->number, $instance ) ) {
+ $instance = $instance[$this->number];
+ // filters the widget's settings, return false to stop displaying the widget
+ $instance = apply_filters('widget_display_callback', $instance, $this, $args);
+ if ( false !== $instance )
+ $this->widget($args, $instance);
+ }
+ }
+
+ /** Deal with changed settings.
+ * Do NOT over-ride this function. */
+ function update_callback( $widget_args = 1 ) {
+ global $wp_registered_widgets;
+
+ if ( is_numeric($widget_args) )
+ $widget_args = array( 'number' => $widget_args );
+
+ $widget_args = wp_parse_args( $widget_args, array( 'number' => -1 ) );
+ $all_instances = $this->get_settings();
+
+ // We need to update the data
+ if ( $this->updated )
+ return;
+
+ $sidebars_widgets = wp_get_sidebars_widgets();
+
+ if ( isset($_POST['delete_widget']) && $_POST['delete_widget'] ) {
+ // Delete the settings for this instance of the widget
+ if ( isset($_POST['the-widget-id']) )
+ $del_id = $_POST['the-widget-id'];
+ else
+ return;
+
+ if ( isset($wp_registered_widgets[$del_id]['params'][0]['number']) ) {
+ $number = $wp_registered_widgets[$del_id]['params'][0]['number'];
+
+ if ( $this->id_base . '-' . $number == $del_id )
+ unset($all_instances[$number]);
+ }
+ } else {
+ if ( isset($_POST['widget-' . $this->id_base]) && is_array($_POST['widget-' . $this->id_base]) ) {
+ $settings = $_POST['widget-' . $this->id_base];
+ } elseif ( isset($_POST['id_base']) && $_POST['id_base'] == $this->id_base ) {
+ $num = $_POST['multi_number'] ? (int) $_POST['multi_number'] : (int) $_POST['widget_number'];
+ $settings = array( $num => array() );
+ } else {
+ return;
+ }
+
+ foreach ( $settings as $number => $new_instance ) {
+ $new_instance = stripslashes_deep($new_instance);
+ $this->_set($number);
+
+ $old_instance = isset($all_instances[$number]) ? $all_instances[$number] : array();
+
+ $instance = $this->update($new_instance, $old_instance);
+
+ // filters the widget's settings before saving, return false to cancel saving (keep the old settings if updating)
+ $instance = apply_filters('widget_update_callback', $instance, $new_instance, $old_instance, $this);
+ if ( false !== $instance )
+ $all_instances[$number] = $instance;
+
+ break; // run only once
+ }
+ }
+
+ $this->save_settings($all_instances);
+ $this->updated = true;
+ }
+
+ /** Generate the control form.
+ * Do NOT over-ride this function. */
+ function form_callback( $widget_args = 1 ) {
+ if ( is_numeric($widget_args) )
+ $widget_args = array( 'number' => $widget_args );
+
+ $widget_args = wp_parse_args( $widget_args, array( 'number' => -1 ) );
+ $all_instances = $this->get_settings();
+
+ if ( -1 == $widget_args['number'] ) {
+ // We echo out a form where 'number' can be set later
+ $this->_set('__i__');
+ $instance = array();
+ } else {
+ $this->_set($widget_args['number']);
+ $instance = $all_instances[ $widget_args['number'] ];
+ }
+
+ // filters the widget admin form before displaying, return false to stop displaying it
+ $instance = apply_filters('widget_form_callback', $instance, $this);
+
+ $return = null;
+ if ( false !== $instance ) {
+ $return = $this->form($instance);
+ // add extra fields in the widget form - be sure to set $return to null if you add any
+ // if the widget has no form the text echoed from the default form method can be hidden using css
+ do_action_ref_array( 'in_widget_form', array(&$this, &$return, $instance) );
+ }
+ return $return;
+ }
+
+ /** Helper function: Registers a single instance. */
+ function _register_one($number = -1) {
+ wp_register_sidebar_widget( $this->id, $this->name, $this->_get_display_callback(), $this->widget_options, array( 'number' => $number ) );
+ _register_widget_update_callback( $this->id_base, $this->_get_update_callback(), $this->control_options, array( 'number' => -1 ) );
+ _register_widget_form_callback( $this->id, $this->name, $this->_get_form_callback(), $this->control_options, array( 'number' => $number ) );
+ }
+
+ function save_settings($settings) {
+ $settings['_multiwidget'] = 1;
+ update_option( $this->option_name, $settings );
+ }
+
+ function get_settings() {
+ $settings = get_option($this->option_name);
+
+ if ( false === $settings && isset($this->alt_option_name) )
+ $settings = get_option($this->alt_option_name);
+
+ if ( !is_array($settings) )
+ $settings = array();
+
+ if ( !empty($settings) && !array_key_exists('_multiwidget', $settings) ) {
+ // old format, convert if single widget
+ $settings = wp_convert_widget_settings($this->id_base, $this->option_name, $settings);
+ }
+
+ unset($settings['_multiwidget'], $settings['__i__']);
+ return $settings;
+ }
+}
+
+/**
+ * Singleton that registers and instantiates WP_Widget classes.
+ *
+ * @package WordPress
+ * @subpackage Widgets
+ * @since 2.8
+ */
+class WP_Widget_Factory {
+ var $widgets = array();
+
+ function WP_Widget_Factory() {
+ add_action( 'widgets_init', array( $this, '_register_widgets' ), 100 );
+ }
+
+ function register($widget_class) {
+ $this->widgets[$widget_class] = new $widget_class();
+ }
+
+ function unregister($widget_class) {
+ if ( isset($this->widgets[$widget_class]) )
+ unset($this->widgets[$widget_class]);
+ }
+
+ function _register_widgets() {
+ global $wp_registered_widgets;
+ $keys = array_keys($this->widgets);
+ $registered = array_keys($wp_registered_widgets);
+ $registered = array_map('_get_widget_id_base', $registered);
+
+ foreach ( $keys as $key ) {
+ // don't register new widget if old widget with the same id is already registered
+ if ( in_array($this->widgets[$key]->id_base, $registered, true) ) {
+ unset($this->widgets[$key]);
+ continue;
+ }
+
+ $this->widgets[$key]->_register();
+ }
+ }
+}
+