Updated "Node + Redis = Fun" to work with v0.2.0

articles/node-redis-fun.markdown

@@ -1,7 +1,7 @@
 Title: Node + Redis = Fun
 Author: Nikhil Marathe
-Date: Tue Feb 23 2010 21:20:20 GMT+530 (IST)
-Node: v0.1.91
+Date: Mon Sep 06 2010 12:48:20 GMT+530 (IST)
+Node: v0.2.0
 
 node brings asynchronous, evented I/O to the server. Redis gives you a blazing fast database with support for strings, lists and sets. Both Redis and Node.js follow certain patterns, Redis for data-storage, and node for event based programming. I hope to give an introduction to both in this article. By the time we are done, we will have built a [Pastebin][] service.
 
@@ -13,7 +13,7 @@ I will assume that the reader is comfortable with Javascript, including using ev
 
 Before we get down to the code, here is the software you will need:
 
-* [node][] ( we will use [v0.1.91](http://github.com/ry/node/downloads) )
+* [node][] ( we will use [v0.2.0](http://github.com/ry/node/downloads) )
 * [Redis][]
 * [redis-node-client][] - to connect to Redis from node. Already bundled within snip.
 * [nerve][] - A micro-framework to handle routing. Use the bundled version which works with node v0.1.91.
@@ -175,12 +175,12 @@ It would have been even cooler if redis-node-client supported streaming the data
                         "-f", "html",
                         "-O", "full,style=pastie",
                         "-P", "title=Snippet #" + id ] );
-    pyg.stdout.addListener( "data", function( coloured ) {
+    pyg.stdout.on( "data", function( coloured ) {
       if( coloured )
         res.write( coloured );
     } );
 
-    pyg.addListener( 'exit', function() {
+    pyg.on( 'exit', function() {
       res.end();
     });
 

articles/node-redis-fun/snip.js

@@ -5,6 +5,29 @@ var redis = require('redis-client')
   , cp = require('child_process')
   , _ = require('underscore')._;
 
+/* Passes cb to a new instance redis.Client.connect
+ * but handles error in connecting
+ * accepts optional errback as second argument
+ * the callback gets a this.redis representing the redis object
+ *
+ * Returns nothing
+ */
+var withRedis = function( cb ) {
+  var errback = arguments[1];
+
+  var r = redis.createClient();
+
+  r.stream.on( 'connect', _.bind( cb, { redis : r } ) );
+
+  r.stream.on( "end", function(error) {
+    if( error ) {
+      process.stdio.writeError( "Error connecting to Redis database\n" );
+      if( typeof(errback) === "function" )
+        errback();
+    }
+  });
+}
+
 var languages = 
  [["apacheconf", "ApacheConf"],
   ["applescript", "AppleScript"],
@@ -145,7 +168,6 @@ var genLanguageList = function() {
   } );
 }
 
-//formHtml
 var formHtml = '<form action="/add" method="post">'
       +  '<label for="code">Paste code</label><br>'
       +  '<textarea name="code" rows="25" cols="80"></textarea><br>'
@@ -155,24 +177,22 @@ var formHtml = '<form action="/add" method="post">'
       +  '</select>'
       +  '<input type="submit" value="Paste!" /></form>';
 
-//getPostParams
 var getPostParams = function(req, callback){ 
   var body = ''; 
-  req.addListener('data', function(chunk){
+  req.on('data', function(chunk){
      body += chunk;
    }) 
-   .addListener('end', function() { 
+   .on('end', function() { 
      var obj = qs.parse(  body.replace( /\+/g, ' ' ) ) ;
      callback( obj );
    });
 } 
 
-//addSnippet
 var addSnippet = function( req, res ) {
   getPostParams( req, function( obj ) {
       var r = redis.createClient();
 
-      r.stream.addListener( 'connect', function() {
+      r.stream.on( 'connect', function() {
         r.incr( 'nextid' , function( err, id ) {
           r.set( 'snippet:'+id, JSON.stringify( obj ), function() {
             var msg = 'The snippet has been saved at <a href="/'+id+'">'+req.headers.host+'/'+id+'</a>';
@@ -183,19 +203,18 @@ var addSnippet = function( req, res ) {
     });
 };
 
-//showSnippet
 var showSnippet = function( req, res, id ) {
     var r = redis.createClient();
-    r.stream.addListener( 'connect', function() {
+    r.stream.on( 'connect', function() {
       r.get( 'snippet:'+id, function( err, data ) {
         if( !data ) {
-          res.sendHeader( 404 );
+          res.writeHead( 404 );
           res.write( "No such snippet" );
           res.end();
           return;
         }
 
-        res.sendHeader( 200, { "Content-Type" : "text/html" } );
+        res.writeHead( 200, { "Content-Type" : "text/html" } );
 
         var obj = JSON.parse( data.toString() );
         var shortcode = languages.filter( function(el) { 
@@ -207,12 +226,12 @@ var showSnippet = function( req, res, id ) {
                             "-f", "html",
                             "-O", "full,style=pastie",
                             "-P", "title=Snippet #" + id ] );
-        pyg.stdout.addListener( "data", function( coloured ) {
+        pyg.stdout.on( "data", function( coloured ) {
           if( coloured )
             res.write( coloured );
         } );
 
-        pyg.addListener( 'exit', function() {
+        pyg.on( 'exit', function() {
           res.end();
         });
 
@@ -224,8 +243,6 @@ var showSnippet = function( req, res, id ) {
   });
 }
 
-//create
-
 nerve.create( [
   [ /^\/([0-9]+)/, showSnippet ],
   [ nerve.post("/add"), addSnippet ],

authors/Nikhil Marathe.markdown

@@ -3,6 +3,6 @@ Bitbucket: nikhilm
 Email: nsm.nikhil@gmail.com
 Homepage: http://kodeclutz.blogspot.com
 
-I am a second year ( sophomore ) student at DA-IICT Gandhinagar in India. Currently I contribute to [KDE](http://www.kde.org) besides experimenting with *lots* of different languages and open source technologies. At this point I haven't decided what area of computers I am really interested in and so I work at all levels, from system calls to web applications.
+I am a third year student at DA-IICT Gandhinagar in India. Currently I contribute to [KDE](http://www.kde.org) besides experimenting with *lots* of different languages and open source technologies. At this point I haven't decided what area of computers I am really interested in and so I work at all levels, from system calls to web applications.
 
 I spend the rest of the day playing football, reading and enjoying college life. Willing to work for food :).