ThatGerber/dfp-ads

<?php

/**
 * Ad Position Widget
 *
 * Simple widget to include an ad position
 */
class DFP_Ads_Widget extends WP_Widget {

    /**
     * Unique identifier for your widget.
     *
     * The variable name is used as the text domain when internationalizing strings
     * of text. Its value should match the Text Domain file header in the main
     * widget file.
     *
     * @access protected
     * @since  0.0.1
     *
     * @var      string
     */
    protected $widget_slug = 'dfp-ad-widget';

    /**
     * Widget form fields
     *
     * Holds the fields that will be added to the widget form
     *
     * @access protected
     * @since  0.0.1
     *
     * @var      array
     */
    protected $fields = array(
        'position_title'
    );

    /**
     * PHP5 Constructor
     *
     * Specifies the class name and description, instantiates the widget,
     * loads localization files, and includes necessary stylesheets and JavaScript.
     *
     * @access public
     * @since  0.0.1
     */
    public function __construct() {

        parent::__construct(
            $this->get_widget_slug(),
            __( 'DFP Ad Position', $this->get_widget_slug() ),
            array(
                'classname'   => $this->get_widget_slug() . '-class',
                'description' => __( 'Displays an ad position', $this->get_widget_slug() )
            )
        );

        // Refreshing the widget's cached output with each new post
        add_action( 'save_post', array( $this, 'flush_widget_cache' ) );
        add_action( 'deleted_post', array( $this, 'flush_widget_cache' ) );
        add_action( 'switch_theme', array( $this, 'flush_widget_cache' ) );
    }

    /**
     * Outputs the content of the widget.
     *
     * @since  0.0.1
     * @access public
     *
     * @param array $args     The array of form elements
     * @param array $instance The current instance of the widget
     */
    public function widget( $args, $instance ) {
        echo $args['before_widget'];
        dfp_ad_position( $instance['position_title'] );
        echo $args['after_widget'];
    }

    /**
     * Generates the administration form for the widget.
     *
     * @since  0.0.1
     * @access public
     *
     * @param array instance The array of keys and values for the widget.
     *
     * @return mixed
     */
    public function form( $instance ) {
        $id    = ( $this->get_field_id( 'position_title' ) !== null ? $this->get_field_id( 'position_title' ) : '' );
        $name  = ( $this->get_field_name( 'position_title' ) !== null ? $this->get_field_name( 'position_title' ) : '' );
        $value = ( isset( $instance['position_title'] ) ? $instance['position_title'] : '' );
        ?>
        <h4><label for="<?php _e( $id ); ?>"><?php _e( 'Ad Position', 'dfp-ads' ); ?></label></h4>
        <p>
            <select class="widefat" name="<?php _e( $name ); ?>" id="<?php _e( $id ); ?>">
                <?php dfp_ad_select_options( $value ); ?>
            </select>
        </p>
        <?php
    }

    /**
     * Processes the widget's options to be saved.
     *
     * @since  0.0.1
     * @access public
     *
     * @param array new_instance The new instance of values to be generated via the update.
     * @param array old_instance The previous instance of values before the update.
     *
     * @return array
     */
    public function update( $new_instance, $old_instance ) {

        foreach ( $this->fields as $field ) {
            $instance[ $field ] = $new_instance[ $field ];
        }

        return $instance;
    }

    /**
     * Return the widget slug.
     *
     * @since  0.0.1
     * @access public
     *
     * @return string Plugin slug variable.
     */
    public function get_widget_slug() {

        return $this->widget_slug;
    }

    /**
     * Flushes the cache
     *
     * @since  0.0.1
     * @access public
     */
    public function flush_widget_cache() {
        wp_cache_delete( $this->get_widget_slug(), 'widget' );
    }

}