Add Google Apps Script with Updates

- Fix RSS link tag to link to the actual twitter page it is displaying
  results for instead of the API page.
- Remove extra white space.
- Update to 4 space tabs.
- Coding standards cleanup.
- Update main doc block.

twitter-rss-google-apps-script.js

@@ -0,0 +1,201 @@
+/**
+ * Twitter RSS Feeds - Google Apps Script
+ *
+ * Google Apps Script to use Twitter API v1.1 to create RSS feeds of
+ * user's timeline, search results, user's favorites, or Twitter
+ * Lists.
+ *
+ * @author Amit Agarwal <amit@labnol.org>
+ * @author Mitchell McKenna <mitchellmckenna@gmail.com>
+ */
+
+function start() {
+    // Get your Twitter keys from dev.twitter.com/apps
+    var CONSUMER_KEY = "YOUR_TWITTER_CONSUMER_KEY";
+    var CONSUMER_SECRET = "YOUR_TWITTER_CONSUMER_SECRET";
+
+    initialize(CONSUMER_KEY, CONSUMER_SECRET);
+}
+
+function initialize(key, secret) {
+    ScriptProperties.setProperty("TWITTER_CONSUMER_KEY", key);
+    ScriptProperties.setProperty("TWITTER_CONSUMER_SECRET", secret);
+
+    var url = ScriptApp.getService().getUrl();
+
+    if (url) {
+        connectTwitter();
+
+        var msg = "";
+
+        msg += "Sample RSS Feeds for Twitter\n";
+        msg += "============================";
+
+        msg += "\n\nTwitter Timeline of user @labnol";
+        msg += "\n" + url + "?action=timeline&q=labnol";
+
+        msg += "\n\nTwitter Favorites of user @labnol";
+        msg += "\n" + url + "?action=favorites&q=labnol";
+
+        msg += "\n\nTwitter List labnol/friends-in-india";
+        msg += "\n" + url + "?action=list&q=labnol/friends-in-india";
+
+        msg += "\n\nTwitter Search for New York";
+        msg += "\n" + url + "?action=search&q=new+york";
+
+        msg += "\n\nYou should replace the value of 'q' parameter in the URLs as per requirement.";
+        msg += "\n\nFor help, please refer to http://www.labnol.org/?p=27931";
+
+        MailApp.sendEmail(Session.getActiveUser().getEmail(), "Twitter RSS Feeds", msg);
+    }
+}
+
+function doGet(e) {
+    var a = e.parameter.action;
+    var q = e.parameter.q;
+
+    var feed;
+    var permalink;
+
+    switch (a) {
+        case "timeline":
+            feed = "https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=" + q;
+            permalink = "https://twitter.com/" + q;
+            break;
+        case "search":
+            feed = "https://api.twitter.com/1.1/search/tweets.json?q=" + encodeString (q);
+            permalink = "https://twitter.com/search?q=" + encodeString (q);
+            break;
+        case "favorites":
+            feed = "https://api.twitter.com/1.1/favorites/list.json?screen_name=" + q;
+            permalink = "https://twitter.com/" + q + "/favorites/";
+            break;
+        case "list":
+            var i = q.split("/");
+            feed = "https://api.twitter.com/1.1/lists/statuses.json?slug=" + i[1] + "&owner_screen_name=" + i[0];
+            permalink = "https://twitter.com/" + q;
+            break;
+        default:
+            feed = "https://api.twitter.com/1.1/statuses/user_timeline.json";
+            permalink = "https://twitter.com";
+            break;
+    }
+
+    var id = Utilities.base64Encode(feed);
+
+    var cache = CacheService.getPublicCache();
+
+    var rss   = cache.get(id);
+
+    if (!rss) {
+        rss = jsonToRss(feed, permalink, a, q);
+
+        cache.put(id, rss, 900);
+    }
+
+    return ContentService.createTextOutput(rss)
+        .setMimeType(ContentService.MimeType.RSS);
+}
+
+
+function jsonToRss(feed, permalink, type, key) {
+    oAuth();
+
+    var options =
+    {
+        "method": "get",
+        "oAuthServiceName":"twitter",
+        "oAuthUseToken":"always"
+    };
+
+    try {
+        var result = UrlFetchApp.fetch(feed, options);
+
+        if (result.getResponseCode() === 200) {
+            var tweets = Utilities.jsonParse(result.getContentText());
+
+            if (type == "search") {
+                tweets = tweets.statuses;
+            }
+
+            if (tweets) {
+                var len = tweets.length;
+
+                var rss = "";
+
+                if (len) {
+                    rss = '<?xml version="1.0"?><rss version="2.0">';
+                    rss += ' <channel><title>Twitter ' + type + ': ' + key + '</title>';
+                    rss += ' <link>' + permalink + '</link>';
+                    rss += ' <pubDate>' + new Date() + '</pubDate>';
+
+                    for (var i=0; i<len; i++) {
+                        var sender = tweets[i].user.screen_name;
+                        var tweet = htmlentities(tweets[i].text);
+
+                        rss += "<item><title>" + sender + ": " + tweet + "</title>";
+                        rss += "<author>" + tweets[i].user.name + " (@" + sender + ")</author>";
+                        rss += "<pubDate>" + tweets[i].created_at + "</pubDate>";
+                        rss += "<guid isPermaLink='false'>" + tweets[i].id_str + "</guid>";
+                        rss += "<link>https://twitter.com/" + sender + "/statuses/" + tweets[i].id_str + "</link>";
+                        rss += "<description>" + tweet + "</description>";
+                        rss += "</item>";
+                    }
+
+                    rss += "</channel></rss>";
+
+                    return rss;
+                }
+            }
+        }
+    } catch (e) {
+        Logger.log(e.toString());
+    }
+}
+
+function connectTwitter() {
+    oAuth();
+
+    var search = "https://api.twitter.com/1.1/application/rate_limit_status.json";
+
+    var options =
+    {
+        "method": "get",
+        "oAuthServiceName":"twitter",
+        "oAuthUseToken":"always"
+    };
+
+    try {
+        var result = UrlFetchApp.fetch(search, options);
+    } catch (e) {
+        Logger.log(e.toString());
+    }
+}
+
+function encodeString(q) {
+    var str = encodeURIComponent(q);
+    str = str.replace(/!/g,'%21');
+    str = str.replace(/\*/g,'%2A');
+    str = str.replace(/\(/g,'%28');
+    str = str.replace(/\)/g,'%29');
+    str = str.replace(/'/g,'%27');
+    return str;
+}
+
+function htmlentities(str) {
+    str = str.replace(/&/g, "&amp;");
+    str = str.replace(/>/g, "&gt;");
+    str = str.replace(/</g, "&lt;");
+    str = str.replace(/"/g, "&quot;");
+    str = str.replace(/'/g, "&#039;");
+    return str;
+}
+
+function oAuth() {
+    var oauthConfig = UrlFetchApp.addOAuthService("twitter");
+    oauthConfig.setAccessTokenUrl("https://api.twitter.com/oauth/access_token");
+    oauthConfig.setRequestTokenUrl("https://api.twitter.com/oauth/request_token");
+    oauthConfig.setAuthorizationUrl("https://api.twitter.com/oauth/authorize");
+    oauthConfig.setConsumerKey(ScriptProperties.getProperty("TWITTER_CONSUMER_KEY"));
+    oauthConfig.setConsumerSecret(ScriptProperties.getProperty("TWITTER_CONSUMER_SECRET"));
+}