Wordpress_Twitter_Widget.php

<?php
/**
 * Plugin Name: p47 Twitter Widget
 * Plugin URI: http://point47.com
 * Description: Displays any message designated
 * Version: 1.0
 * Author: Sorin Gitlan
 * Author URI: http://point47.com
 */

class p47_Twitter_Widget extends WP_Widget {

    public function __construct(){
        $params = array(
            'description' => 'Displays and cache tweets',
            'name'        => 'p47 Twitter Widget'
        );

        parent::__construct('p47_Twitter_Widget', '', $params);
    }

    /**
     * Responsible for the form in the Widget management area
     * @param  Array $instance The form array Post data
     * @return String
     */
    public function form($instance){
        extract($instance);

        ?>
        <p>
            <label for="<?php echo $this->get_field_id('title'); ?>">Title: </label>
            <input class="widefat" 
                id="<?php echo $this->get_field_id('title'); ?>"
                name="<?php echo $this->get_field_name('title'); ?>"
                value="<?php if(isset($title)) echo esc_attr($title); ?>"
            >
        </p>

        <p>
            <label for="<?php echo $this->get_field_id('username'); ?>">Twitter Username: </label>
            <input class="widefat" 
                id="<?php echo $this->get_field_id('username'); ?>"
                name="<?php echo $this->get_field_name('username'); ?>"
                value="<?php if(isset($username)) echo esc_attr($username); ?>"
            >
        </p>

        <p>
            <label for="<?php echo $this->get_field_id('tweet_count'); ?>">Number of tweets to receive: </label>
            <input type="number" min="1" max="10"
                id="<?php echo $this->get_field_id('tweet_count'); ?>"
                name="<?php echo $this->get_field_name('tweet_count'); ?>"
                value="<?php echo !empty($tweet_count) ? $tweet_count : 5;  ?>"
            >
        </p>

        <?php
    }

    /**
     * Responsible to display the results of our form
     * @param Array $args       the values that can be used to tailor how the widget displays
     * @param Array $instance   the values that are available from the widget area
     * @return String 
     */
    public function widget($args, $instance){
        extract($args);
        extract($instance);

        $title = !empty($title) ? apply_filters( 'widget_title', $title ) : 'Recent tweets';
        $data = $this->twitter($tweet_count, $username);

        if( false !== $data && isset($data->tweets) ){
            echo $before_widget;
                echo $before_title;
                    echo $title;
                echo $after_title;
                echo '<ul><li>'. implode('</li><li>', $data->tweets) . '</li></ul>';  
            echo $after_widget;
        }

    }

    /**
     * 
     * @param  [type] $tweet_count [description]
     * @param  [type] $username    [description]
     * @return [type]              [description]
     */
    private function twitter($tweet_count, $username){
        if(empty($username)) return false;
        
        // get cached data
        $tweets = get_transient( 'recent_tweets_widget' );

        // fetch tweets if no cached data or username or tweet_count changed
        if( !$tweets ||
            $tweets->username !== $username ||
            $tweets->tweet_count !== $tweet_count
        ){
            return $this->fetch_tweets($tweet_count, $username);
        }

        return $tweets;
    }

    /**
     * 
     * @param  [type] $tweet_count [description]
     * @param  [type] $username    [description]
     * @return [type]              [description]
     */
    private function fetch_tweets($tweet_count, $username){

        $tweets = $this->curl('https://api.twitter.com/1/statuses/user_timeline.json?include_entities=true&include_rts=1&screen_name=@' 
                        . $username . '&count=' . $tweet_count . '&published_when=1');

        $data = new stdClass();
        $data->username     = $username;
        $data->tweet_count  = $tweet_count;
        $data->tweets       = array();

        foreach (json_decode($tweets) as $tweet) {
            $data->tweets[] =  $this->filter_tweet( $tweet->text );
        }

        // standardized way of storing cached data in the database temporarily by giving it a custom 
        // name and a timeframe after which it will expire and be deleted.
        set_transient( 'recent_tweets_widget', $data,  60*5);

        return $data;
    }

    /**
     * 
     * @param  [type] $tweet [description]
     * @return [type]        [description]
     */
    private function filter_tweet( $tweet ){
        $tweet = preg_replace('/(http[^\s]+)/im', '<a href="$1">$1</a>', $tweet);
        $tweet = preg_replace('/@([^\s]+)/i', '<a href="http://twitter.com/$1">@$1</a>', $tweet);
        return $tweet;
    }

    /**
     * 
     * @param  [type] $url [description]
     * @return [type]      [description]
     */
    private function curl($url){

        $curl = curl_init($url);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
        return curl_exec($curl);
        curl_close($curl);

    }

}




add_action('widgets_init', function(){
    register_widget( 'p47_Twitter_Widget' );
});