Beginnings of a class for building out meta tags for twitter cards. https://dev.twitter.com/docs/cards

twitter-card-generator.php

<?php
/*
Plugin Name: Twitter Card Generator 
Description: This plugin provides a class to generate the meta tag properties for a player twitter card.
Version: 0.1
Author: Matthew Simo
*/
 
if(!class_exists('Twitter_Card')){
  class Twitter_Card{

    private static $types = array(
      'summary',
      'summary_large_image',
      'photo',
      'gallery',
      'app',
      'player',
      'product'
    );

    private static $reqsByType = array(
      'summary' => array('title', 'description'), // https://dev.twitter.com/docs/cards/types/summary-card
      'summary_large_image' => array('title', 'description'), // https://dev.twitter.com/docs/cards/large-image-summary-card
      'photo' => array('image'), // https://dev.twitter.com/docs/cards/types/photo-card
      'gallery' => array('image0', 'image1', 'image2', 'image3'), // https://dev.twitter.com/docs/cards/types/gallery-card
      'app' => array('app:id:iphone', 'app:id:ipad', 'app:id:googleplay'), // https://dev.twitter.com/docs/cards/types/app-card
      'player' => array('title', 'description', 'player', 'player:width', 'player:height', 'image'), // https://dev.twitter.com/docs/cards/types/player-card
      'product' => array('title', 'description', 'image', 'data1', 'label1', 'data2', 'label2'), // https://dev.twitter.com/docs/cards/types/product-card
    );
    
    public function __construct(){
 
    }

    /*
     * Generate Player Twitter Card Tags
     *
     * Returns the html for the meta tags based on passed in settings array. 
     * https://dev.twitter.com/docs/cards/types/player-card
     *
     * @param Array $settings Key/Value Settings, see twitter card for keys & valid values based on type.
     * @return String The chunk of twitter card meta tags
     */
    public function generate($settings = array()){

      // Set some defaults
      $default_settings = array(
        'type'  => 'player',
        'title' => '',
        'description' => '',
        'player' => '',
        'player:width' => '',
        'player:height' => '',
        'image' => '',



        'player:stream' => '',
        'player:stream:content_type' => ''
      );

      // Combine passed in settings with defaults
      $settings = array_merge($default_settings, $settings);


      // Exit if some required settings aren't set and it's type player, this is ugly, replace with class method
      if( ( $setting['type'] == 'player' ) && ( !isset($settings['title']) || 
                                                !isset($settings['description']) || 
                                                !isset($settings['player']) || 
                                                !isset($settings['player:width']) || 
                                                !isset($settings['player:height']) || 
                                                !isset($settings['image']) ) ) return;

      $html = '';
      foreach($settings as $k => $v) {
        $html .= $this->build_tag($k, $v);
      }
      
      return $html;
 
    }

    /*
     * Build Tag
     * This will build the meta tag for the passed in key/value pair.
     *
     * @param String $key Settings key, we'll prepend this with 'twitter:'.
     * @param String $value The Value to be used for the tag.
     *
     * @return String Markup meta tag
     */
    private function build_tag($key, $value) {
      return '<meta name="twitter:' . $key . '" content="' . $value . '">'."\n";
    }
 
  }

}