added oauth utils for fetching request and access tokens

Author: Tim Whitlock

examples/oauth-complete.js

@@ -0,0 +1,26 @@
+/**
+ * Example of completing OAuth flow by requesting access token from authorized request token
+ */
+
+
+var client = require('../lib/twitter').createClient();
+
+client.setAuth ( 
+    'your consumer key',
+    'your consumer secret',
+    'request token from step 1',  
+    'request secret from step 1'
+);
+
+var verifier = 'PIN or code from user flow';
+
+client.fetchAccessToken( verifier, function( token, raw, status ){
+    if( token ){
+        console.log('Credentials for @'+raw.screen_name );
+        console.log(' > Access key:    '+token.key );
+        console.log(' > Access secret: '+token.secret );
+    }
+    else {
+        console.error('Status '+status+', failed to fetch access token');
+    }
+} );

examples/oauth-start.js

@@ -0,0 +1,21 @@
+/**
+ * Example of starting OAuth flow by fetch a request token.
+ */
+
+
+var client = require('../lib/twitter').createClient();
+
+client.setAuth ( 
+    'your consumer key',
+    'your consumer secret'
+);
+
+client.fetchRequestToken( 'oob', function( token, raw, status ){
+    if( token ){
+        console.log('Request secret: '+token.secret );
+        console.log('Authorize at: '+ token.getAuthorizationUrl() );
+    }
+    else {
+        console.error('Status '+status+', failed to fetch request token');
+    }
+} );

lib/twitter.js

@@ -29,7 +29,7 @@ function OAuthToken( key, secret ){
     this.secret = secret;
 }
 
-OAuthToken.prototype.get_authorization_url = function(){
+OAuthToken.prototype.getAuthorizationUrl = function(){
     return TWITTER_OAUTH_AUTHORIZE_URL+'?oauth_token='+encodeURIComponent(this.key);
 }
 
@@ -150,6 +150,9 @@ TwitterClient.prototype.post = function( requestPath, requestArgs, callback ){
 }
 
 TwitterClient.prototype._rest = function( requestMethod, requestPath, requestArgs, callback ){
+    if( ! this.hasAuth() ){
+        throw new Error('Twitter REST client not authenticated');
+    }
     var requestUri = TWITTER_API_BASE + '/' + requestPath + '.json';
     return this.call( requestMethod, requestUri, requestArgs, function( res ) {
         // started to receive response from twitter
@@ -183,6 +186,9 @@ TwitterClient.prototype._rest = function( requestMethod, requestPath, requestArg
 }
 
 TwitterClient.prototype.stream = function( requestPath, requestArgs, callback ){
+    if( ! this.hasAuth() ){
+        throw new Error('Twitter streaming client not authenticated');
+    }
     var requestMethod = 'GET',
         requestUri = TWITTER_STREAM_BASE+'/'+requestPath+'.json';
     if( 'user' === requestPath ){
@@ -220,15 +226,12 @@ TwitterClient.prototype.stream = function( requestPath, requestArgs, callback ){
 }
 
 TwitterClient.prototype.call = function( requestMethod, requestUri, requestArgs, callback ){
-    if( ! this.hasAuth() ){
-        throw new Error('Twitter client not authenticated');
-    }
     requestMethod = String( requestMethod||'GET' ).toUpperCase();
     // build and sign request parameters
-    var params = new OAuthParams( requestArgs )
-         .setConsumer( this.consumerToken )
-         .setAccess( this.accessToken )
-         .sign( requestMethod, requestUri );
+    var params = new OAuthParams( requestArgs );
+    this.consumerToken && params.setConsumer( this.consumerToken );
+    this.accessToken   && params.setAccess( this.accessToken );
+    params.sign( requestMethod, requestUri );
     // grab authorization header and any remaining params
     var oauth = params.getHeader(),
         query = params.serialize();
@@ -267,9 +270,33 @@ TwitterClient.prototype.abort = function(){
     }
 }
 
+TwitterClient.prototype.fetchRequestToken = function( url, callback ){
+    var requestUri  = TWITTER_OAUTH_REQUEST_TOKEN_URL,
+        requestArgs = { oauth_callback: url||'oob' };
+    return this._oauthExchange( requestUri, requestArgs, callback );
+}
 
+TwitterClient.prototype.fetchAccessToken = function( verifier, callback ){
+    var requestUri  = TWITTER_OAUTH_ACCESS_TOKEN_URL,
+        requestArgs = { oauth_verifier: verifier };
+    return this._oauthExchange( requestUri, requestArgs, callback );
+}
 
-
+TwitterClient.prototype._oauthExchange = function( requestUri, requestArgs, callback ){
+    this.call( 'POST', requestUri, requestArgs, function( res ){
+        // started to receive response from twitter
+        res.setEncoding('utf8');
+        var body = '';
+        res.on('data', function( chunk ) {
+            body += chunk;
+        } );
+        res.on('end', function(){
+            var params = require('querystring').parse( body );
+            var token = params.oauth_token && params.oauth_token_secret && new OAuthToken( params.oauth_token, params.oauth_token_secret );
+            'function' == typeof callback && callback( token, params, res.statusCode );
+        } );
+    } );
+}