Changeset 1105 for sites/trunk/wordcamp.org/public_html/wp-content/themes/wordcamp-central-2012/functions.php

Timestamp:

01/08/2015 06:29:55 PM (10 years ago)

Author:

iandunn

Message:

Central Theme: Replace sessions on the homepage with latest tweets.

Props mj12982 for the design

File:

• sites/trunk/wordcamp.org/public_html/wp-content/themes/wordcamp-central-2012/functions.php (modified) (3 diffs)

sites/trunk/wordcamp.org/public_html/wp-content/themes/wordcamp-central-2012/functions.php

@@ -36 +36 @@
         add_action( 'init', array( __CLASS__, 'process_forms' ) );
         add_action( 'wp_enqueue_scripts', array( __CLASS__, 'enqueue_scripts' ) );
+        add_action( 'wp_ajax_get_latest_wordcamp_tweets', array( __CLASS__, 'get_latest_tweets' ) );
+        add_action( 'wp_ajax_nopriv_get_latest_wordcamp_tweets', array( __CLASS__, 'get_latest_tweets' ) );
 
         add_filter( 'excerpt_more', array( __CLASS__, 'excerpt_more' ), 11 );
@@ -181 +183 @@
     static function enqueue_scripts() {
         wp_enqueue_style( 'central', get_stylesheet_uri(), array(), 3 );
-        wp_enqueue_script( 'wordcamp-central', get_stylesheet_directory_uri() . '/js/central.js', array(), '20140909', true );
+        wp_enqueue_script( 'wordcamp-central', get_stylesheet_directory_uri() . '/js/central.js', array( 'jquery', 'underscore' ), 1, true );
+
+        wp_localize_script( 'wordcamp-central', 'wordcampCentralOptions', array( 'ajaxURL' => admin_url( 'admin-ajax.php' ) ) );
 
         /* We add some JavaScript to pages with the comment form
@@ -425 +429 @@
     public static function can_subscribe() {
         return class_exists( 'Jetpack_Subscriptions' ) && is_callable( array( 'Jetpack_Subscriptions', 'subscribe' ) );
+    }
+
+    /**
+     * Fetch the latest tweets from the @WordCamp account
+     *
+     * This is an AJAX callback returning JSON-formatted data.
+     *
+     * We're manually expiring/refreshing the transient to ensure that we only ever update it when we have a
+     * valid response from the API. If there is a problem retrieving new data from the API, then we want to
+     * continue displaying the valid cached data until we can successfully retrieve new data. The data is still
+     * stored in a transient instead of an option, though, so that it can be cached in memory.
+     *
+     * Under certain unlikely conditions, this could cause an API rate limit violation. If the data is expired
+     * and we can connect to the API at the network level, but then the request fails at the application level
+     * (invalid credentials, etc), then we'll be hitting the API every time this function is called. If that
+     * does ever happen, it could be fixed by setting the timestamp of the last attempt in a transient and only
+     * issuing another attempt if ~2 minutes have passed.
+     */
+    public static function get_latest_tweets() {
+        $transient_key = 'wcc_latest_tweets';
+        $tweets        = get_transient( $transient_key );
+        $expired       = $tweets['last_update'] < strtotime( 'now - 15 minutes' );
+
+        if ( ! $tweets || $expired ) {
+            $response = wp_remote_get(
+                'https://api.twitter.com/1.1/statuses/user_timeline.json?count=6&trim_user=true&exclude_replies=true&include_rts=false&screen_name=wordcamp',
+                array(
+                    'headers' => array( 'Authorization' => 'Bearer ' . TWITTER_BEARER_TOKEN_WORDCAMP_CENTRAL ),
+                )
+            );
+
+            if ( ! is_wp_error( $response ) ) {
+                $tweets['tweets'] = json_decode( wp_remote_retrieve_body( $response ) );
+
+                /*
+                 * Remove all but the first 3 tweets
+                 *
+                 * The Twitter API includes retweets in the `count` parameter, even if include_rts=false is passed,
+                 * so we have to request more tweets than we actually want and then cut it down here.
+                 */
+                if ( $tweets['tweets'] ) {
+                    $tweets['tweets']      = array_slice( $tweets['tweets'], 0, 3 );
+                    $tweets['tweets']      = self::sanitize_format_tweets( $tweets['tweets'] );
+                    $tweets['last_update'] = time();
+
+                    set_transient( $transient_key, $tweets );
+                }
+            }
+        }
+
+        wp_send_json_success( $tweets );
+    }
+
+    /**
+     * Sanitize and format the tweet objects
+     *
+     * Whitelist the fields to cut down on how much data we're storing/transmitting, but also to force
+     * future devs to manually enable/sanitize any new fields that are used, which avoids the risk of
+     * accidentally using an unsafe value.
+     *
+     * @param array $tweets
+     *
+     * @return array
+     */
+    protected static function sanitize_format_tweets( $tweets ) {
+        $whitelisted_fields = array( 'id_str' => '', 'text' => '', 'created_at' => '' );
+
+        foreach ( $tweets as & $tweet ) {
+            $tweet           = (object) shortcode_atts( $whitelisted_fields, $tweet );
+            $tweet->id_str   = sanitize_text_field( $tweet->id_str );
+            $tweet->text     = wp_kses( $tweet->text, wp_kses_allowed_html( 'data' ), array( 'http', 'https', 'mailto' ) );
+            $tweet->text     = make_clickable( $tweet->text );
+            $tweet->text     = self::link_hashtags_and_usernames( $tweet->text );
+            $tweet->time_ago = human_time_diff( strtotime( $tweet->created_at ) );
+        }
+
+        return $tweets;
+    }
+
+    /**
+     * Convert usernames and hashtags to links
+     *
+     * Based on Tagregator's TGGRSourceTwitter::link_hashtags_and_usernames().
+     *
+     * @param string $text
+     *
+     * @return string
+     */
+    protected static function link_hashtags_and_usernames( $content ) {
+        $content = preg_replace( '/@(\w+)/',       '<a href="https://twitter.com/\\1"          class="wc-tweets-username">@\\1</a>', $content );
+        $content = preg_replace( '/(?<!&)#(\w+)/', '<a href="https://twitter.com/search?q=\\1" class="wc-tweets-tag"     >#\\1</a>', $content );
+
+        return $content;
     }