This can apply to any language and architecture, but I've been applying it in my Node.js programming. The idea of combining is to have all of your resources separated for development, but combined at runtime since the browser doesn't care about your structure, and fewer files is fewer requests, so the page loads faster. I did this with javascript at first, but was later faced with a huge css file, and decided to take the same approach.

I was parsing an international date format, like this: 2011-08-04T11:23:21.345Z. After getting back December as the month for August, I was mildly perplexed. Here was the issue

From the Mozilla docs for parseInt: If the input string begins with "0", radix is eight (octal). This feature is non-standard, and some implementations deliberately do not support it (instead using the radix 10). For this reason always specify a radix when using parseInt.

Always specify a radix!!

Yesterday I lied when I said it would be the last Node.js post for a while! Oh well.

So today I was looking to make my project site a little faster, particularly on the mobile side. Actually this was the last three days worth of trying to figure stuff out. Node.js has plenty of compression library add-ons (modules), but the most standard compression tool out there is gzip (and gunzip). In the Accept-Encoding request header, the browser will tell you whether or not it can handle it. Most can...

This seemed like an obvious mechanism to employ to decrease some page load times... not that it's soo slow, but when the traffic gets up there and the site starts bogging down, at least the network will be less of a bottleneck. Some browsers do not support it, so you always have to send uncompressed content in those cases.

So I found a good Node.js compression module that supported BZ2 as well as gzip. The problem was, it was only meant to work with npm (Node's package manager), which for whatever reason, I've stayed away from. I like to keep my modules organized myself, I guess! So I pull the source from github and build the package if it requires it, then make sure I can use it by just calling require("package-name"); It's worked for every case except the first gzip library I found... doh! Luckily, github is a very social place, and lots of developers will just fork a project and fix it. That was where the magic started. I found a fork of the node-compress that fixed these issues, installed the package correctly by just calling ./build.sh (which calls node-waf, which I'm fine with using!), and copied the binary to the correct location within the module directory. So all I had to do was modify my code to require("node-compress/lib/compress"); I'm fine with that too.

Code - gzip.js

var compress = require("node-compress/lib/compress"); var encodeTypes = {"js":1,"css":1,"html":1}; function acceptsGzip(req){ var url = req.url; var ext = url.indexOf(".") == -1 ? "" : url.substring(url.lastIndexOf(".")+1); return (ext in encodeTypes || ext == "") && req.headers["accept-encoding"] != null && req.headers["accept-encoding"].indexOf("gzip") != -1; } function createBuffer(str, enc) { enc = enc || 'utf8'; var len = Buffer.byteLength(str, enc); var buf = new Buffer(len); buf.write(str, enc, 0); return buf; } this.gzipData = function(req, res, data, callback){ if (data != null && acceptsGzip(req)){ var gzip = new compress.Gzip(); var encoded = null; var headers = null; var buf = Buffer.isBuffer(data) ? data : createBuffer(data, "utf8"); gzip.write(buf, function(err, data1){ encoded = data1.toString("binary"); gzip.close(function(err, data2){ encoded = encoded + data2.toString("binary"); headers = { "Content-Encoding": "gzip" }; callback(encoded, "binary", headers); }); }); } else callback(data); }

So it's awesome. Here's a picture of the code working on this page

Quite the improvement, at less than 30% of the size! Soon I'm going to work in a static file handler, so that it doesn't have to re-gzip js and css files every request, although I use caching extensively, so it won't have to re-gzip it for you 10 times in a row, only re-gzip it for 10 different users for the first time... I can see that being a problem in the long run, although, it's still fast as a mofo!

Probably my last post about Node.js for a while. My original implementation of the webserver used page objects in the following way:

index.html -> /site/pages/index.js

Meaning that when index.html was requested, index.js was located and executed. A side effect of this, using the node.js construct "require", is that the js page will only be loaded once. Which was bad because I had my code structured in the following way:

//index.js: this.title = "My page title"; this.load = function(..., finishedCallback){ this.title = figureOutDynamicTitle(parameters); finishedCallback(); }

Granted, when someone went to index.html, there was a very small time that they might get the wrong title, in this example. But for things, like setting an array on the page to the value loaded from the database, or where you might have another case in the load function where the array doesn't get set at all, there's a very good chance that someone will see something that someone else was only supposed to see.

How I fixed this was to pass back the page object to the finishedCallback. The page object was declared, built and passed back all within the context of the load function, so it never has a chance to be wrong! This is how it looks now

//index.js this.load = function(..., finishedCallback){ var page = { title: figureOutDynamicTitle(parameters) }; finishedCallback({ page: page }); }

This works. And it's super fast still.

The Node.js process class is very helpful for cleanup purposes. You can imagine, when writing a rudimentary web server, you might also have a mechanism for tracking sessions. This was definitely the case for me, so we can easily keep track of who's logged in, without exposing much in the way of security.

Having not worked in a way to update all of my code without restarting the server, I have to restart the server when a change is made to the code in order for it to update. This in turn, deletes all of the sessions. I was thinking of a way to handle this, knowing of Node.js's process class, but where to put the code was not immediately obvious in my brain, but once I started coding for this exact purpose, it was a shame that I didn't think of it right away, just for the shear fact that I cannot lie, and I could say "Yeah I thought of it right away" :)

Here's the code:

function closeServer(errno){ console.log("Server closing, serializing sessions"); SessionManager.serialize(config.web.global.sessionStore, function(){ server.close(); process.exit(0); }); } process.on("SIGTERM", closeServer); process.on("SIGINT", closeServer);

Luckily, killproc sends SIGTERM, and pressing CTRL+C sends a SIGINT signal. I've noticed kill also just sends SIGTERM, with SIGKILL being a very explicit option, so we may just have to listen for SIGTERM and SIGINT. Anyway.

sessionStore is the folder to store them in, and it clears them out each time and saves what's in memory, so we don't get months old sessions in there.

I just serialize them using JSON.stringify and deserialize with the counter, JSON.parse. It works beautifully.

The session ID is just a combination of the time, plus some user variables like user agent, hashed and hexed. Here's the code that serializes and deserializes.

SessionManager.prototype.serialize = function(path, callback){ var self = this; fshelp.ensureFolder(path, function(err, exists){ fshelp.clearFolder(path, function(err, exists){ for (id in self.sessions){ if (!self.isExpired(self.sessions[id])) fs.writeFileSync(path + id, JSON.stringify(self.sessions[id]), "utf8"); } delete self.sessions; callback(); }); }); } SessionManager.prototype.deserialize = function(path, callback){ var self = this; fshelp.ensureFolder(path, function(err, exists){ fs.readdir(path,function(err, files){ files.forEach(function(d){ var id = d.substring(d.lastIndexOf("/") + 1); self.sessions[id] = JSON.parse(fs.readFileSync(path + d, "utf8")); }); callback(); }); }); }

Now no one gets logged out when I have to restart my server for any reason!

Since all of this takes place at the end or the beginning, I figured to save some brain power and just use the synchronous operations for writing and reading the files.

<script type="text/javascript">
function cleanseField(str){
str = str.replace(/<(/?)(b|i|u|em)>/ig,"_$1$2_").replace(/<.*?>/g,"").replace(/_(/?)(b|i|u|em)_/ig,"<$1$2>");
return str;
} function doit(){
var str = "<h3>Header</h3>Hello, my name is <eM>jason connell</Em>. <b>You</B> are awesome, like <i>italics</i><<scr"+"ipt>script type='text/javascript'>alert('sup');</sc"+"ript </scr"+"ipt>><u>underline</u>";

var spn = document.getElementById("test");
spn.innerHTML += "<h1>Original</h1>" + str;
spn.innerHTML += "<h1>Cleansed</h1>" + cleanseField(str);
}
</script>

<a href="javascript:void(0);" onclick="doit();">Doit</a>
<span id="test"></span>

Trying to cleanse html but keep certain elements for now. Tested in Chrome and IE 8, but is there a string that will still put out a valid script tag? It's very important.

If only there was a way in HTML that you can specify, "scripts are only valid inside this segment of the page". It's a shame that you could execute a script anywhere.

In my many years of web development, I've come across a lot of good ways that platform authors did stuff, and a lot of bad ways. So I'm writing my version of a web platform on Node.js, and I decided to keep the good stuff, and get rid of what I didn't like. It wasn't easy but I'm pretty much finished by now.

As with most things I develop, I'll decide on an architecture that allows for changes to be made in a way that makes sense, but I'll start with what I want the code to look like. Yes. When I wrote my ORM, I started with the simple line, db.save(obj); (it turns out that's how you do it in MongoDB so I didn't have to write an ORM with Mongo :) When starting a web platform, I started out the same way.

I wanted to write:

<list value="${page.someListVariable}" var="item">
Details for ${item.name}
<include value="/template/item-template.html" item="item" />
</list>

Obvious features here are code and presentation separation, SSIs, simple variable replacement with ${} syntax.

There aren't a lot of tags in my platform. There's an if, which you can use to decide whether to output something. There's an include, which you can pass variables from the main page so you can reuse it on many pages. This one takes an "item" object, which it will refer to in its own code with ${item}.

Recently I added a layout concept. So you can have your layout html in another file, and just put things into the page in the page's actual html. For instance, you might reach the file index.html, which would look like this:

<layout name="main">
<content name="left-column">
<include value="/template/navigation.html" />
</content>
<content name="main-column">
<include value="/template/home-content.html" />
</content>
</layout>

Java Server Faces used a two way data binding mechanism which was really helpful. But then you need controls, like input[type=text] or whatever. My pages will not have two way data binding, but you can use plain html. Which I like better. (However, those controls were very simple to swap due to the generous use of interfaces by Java, and their documentation pretty much mandating their use. e.g. using ValueHolder in Java instead of TextBox, and if you were to make it a "select" or input[type=hidden], your Java code would not have to change, which is one thing I absolutely hate about ASP.NET).

I borrow nothing from PHP.

ASP.NET pretty much does nothing that I like, other than it's easy to keep track of what code gets run when you go to /default.aspx. The code in /default.aspx.cs and whatever Page class that inherits, or master page that it's on. In Java Server Faces you're scrounging through xml files to see which session bean got named "mybean".

My platform is similar to ASP.NET in that for /index.html there's a /site/pages/index.js (have I mentioned that it's built on node.js), that can optionally exist, and can have 1-2 functions implemented in it, which are "load" and "handlePost", if your page is so inclined to handle posts. Another option is to have this file exist, implement neither load nor handlePost, and just have properties in it. It's up to youme.

Here's a sample sitemap page for generating a Google Sitemap xml file:

Html:

<!--?xml version="1.0" encoding="UTF-8"?-->

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url>
<loc>http://${config.hostUrl}/index</loc>
<lastmod>2011-06-16</lastmod>
<changefreq>monthly</changefreq>
<priority>0.5</priority>
</url>
<jsn:foreach value="${page.entries}" var="entry">
<url>
<loc>${entry.loc}</loc>
<lastmod>${entry.lastmod}</lastmod>
<changefreq>${entry.changefreq}</changefreq>
<priority>${entry.priority}</priority>
</url>
</jsn:foreach>
</urlset>

I use the jsn prefix, which just stands for (now, anyway) Javascript Node. I wasn't creative. I guess I can call it "Jason's Site N..." I can't think of an N.

And the javascript:

var date = require("dates"), common = require("../common");

this.entries = [];

this.load = function(site, query, finishedCallback){
var self = this;
var now = new Date(Date.now());
var yesterday = new Date(now.getFullYear(), now.getMonth(), now.getDate());
var yesterdayFormat = date.formatDate("YYYY-MM-dd", yesterday);
common.populateCities(site.db, function(states){
for (var i = 0; i < states.length; i++){
states[i].cities.forEach(function(city){
var entry = {
loc: "http://" + site.hostUrl + "/metro/" + city.state.toLowerCase() + "/" + city.key,
lastmod: yesterdayFormat,
changefreq: "daily",
priority: "1"
}
self.entries.push(entry);
});
}
finishedCallback({contentType: "text/xml"});
});
}

My finishedCallback function can take more parameters, say for handling a JSON request, I could add {contentType: "text/plain", content: JSON.stringify(obj)}.

That's about all there is to it! It's pretty easy to work with so far :) My site will launch soon!

This can lead to some pretty sweet code. For one thing, always add a callback as a parameter to functions you create, to keep with the non-blocking nature. The next thing you need to know is that you will back yourself into a corner!

Take the following code:
collection.find(search, {sort: sort}, function(err, cursor){
cursor.toArray(function(err, messages){
for (var i = 0; i < messages.length; i++){
db.dereference(messages[i].from, function(err, result){
messages[i].from_deref = result;
});
}
callback(messages);
});
});

Backstory: I'm using MongoDB as the backend, I have a message collection, a user collection, and messages have a "from" property that is a DBRef to a user.

You would run this code and find that if you had any number of messages greater than zero, you will probably get a null "from_deref" object, which means the callback at the end was called before it was finished processing. That is if you're lucky enough to not get an error stating that the code "can't set the property from_deref of undefined", which means, usually, that "i" is null or greater than the length of the array by the time the callback for db.dereference calls. If it's not obvious, I'm dereferencing the user's DBRef and storing it in the message's from_deref property.

This is because of the non-blocking nature of Node.js. It's interesting because it makes me think in new ways. Anything that makes you think differently is good in my opinion. So how do we accomplish this and not break anything? Consider the following code as a solution:

collection.find(search, {sort: sort}, function(err, cursor){
cursor.toArray(function(err, messages){
var process = messages.length - 1;
for (var i = 0; i < messages.length; i++){
(function(messages, index){
db.dereference(messages[index].from, function(err, result){
messages[index].from_deref = result;

if (index == process)
callback(messages);
});
})(messages, i);
}

if (messages.length == 0) callback(messages);
});
});

Javascript is awesome. This is basically an anonymous function that I define and call in the same block. The definition is everything inside (function(x,y){}) and the call is in the parentheses following: (messages, i); So this calls the inner block with the value of i that I'm hoping it will (or rather than hoping, I'm confident it will!). And when all dereferences are done, I know that the process variable will be equal to the index (process variable is length - 1 which is the max value the index can have).

Of course, this doesn't take advantage of the node-mongodb-native's library of the nextObject function on the cursor object. That would totally solve this without javascript magic:

cursor.nextObject(function(err, message){
db.dereference(message.from, function(err, result){
message.from_deref = result;
});
});

However, I like the Array...

So there you have it.

I wrote a post for work about using XMPP to send task notifications through Google Talk.

I have a method of debugging that has worked since college. I call it "compose debugging". As I'm writing an email to ask a question, either to the professor who is teaching the course, or since then, the author of a library I'm trying to incorporate into my project (or whose code my project relies solely upon), I find my answer. Sometimes I'll have already sent the email, so I have to send a short "nevermind" email. Basically, that's the content and the subject. "Figured it out..."

Sometimes I pretend that I sent the "nevermind" email without sending the question email, and the recipient is all "WTF?"

Obviously the secret is, I get all of my ideas and problems on paper, which is a million times more organized than my head.

Computers are fun.

Image processing is very important if you are going to allow anyone, even if it's only you, to upload images to your site. The fact of the matter is, not everyone knows how to resize an image, and forcing users to do it will mean less user submitted content on your site, since it's a pain, and other sites let you upload non-processed images. If it's just you uploading images, laziness will take over and you will stop doing it because it's not easy. So get with the times!

I found a Node.js plugin for GraphicsMagick. I learned about both the plugin and GraphicsMagick itself simultaneously. GraphicsMagick is pretty sweet, minus setting it up. After you get it set up though, you can perform many operations on any image format that you configured within GraphicsMagick.

This post will not cover setting up GraphicsMagick (although I will point out that setting LDFLAGS=-L/usr/local/include in my instance saved me from problems with missing LIBPNGxxx.so files), and I couldn't get it to work on my Mac. Here's how I'm using GraphicsMagick, via the excellent Node.js module, gm.

var gm = require("gm"), fs = require("fs");

var basePath = "/path/to/images/";
var maxDimension = 800;
var maxThumbDimension = 170;
var thumbQuality = 90;

var processImages = function(images){
console.log("processing : " + images.length + " image(s)");
images.forEach(function (image, imageIndex){
var fullPath = basePath + image;
var newFilename = basePath + "scaled/" + image;
gm(fullPath).size(function(err, value){
var newWidth = value.width, newHeight = value.height, ratio = 1;
if (value.width > maxDimension || value.height > maxDimension){
if (value.width > maxDimension){
ratio = maxDimension / value.width;
}
else if (value.height > maxDimension){
ratio = maxDimension / value.height;
}
newWidth = value.width * ratio;
newHeight = value.height * ratio;
}

if (newWidth != value.width){
console.log("resizing " + image + " to " + newWidth + "x" + newHeight);
gm(fullPath).resize(newWidth, newHeight).write(newFilename, function(err){
if (err) console.log("Error: " + err);
console.log("resized " + image + " to " + newWidth + "x" + newHeight);
});
}
else copyTheFileToScaledFolder(); // ?? how do you do this?!? :P
}
}
}

I run this as a service instead of putting it in the web application. It is on an interval, and you just let node.js handle it! That part was simple:

var interval = setInterval(function(){ processImages(getImages());}, 4000);

Your getImages function might look like this:

var getImages = function(){
fs.readdir(basePath, function(err, files){
// this won't work...
// filter out folders, non-image files and files that have already been processed
processImages(files);
// maybe delete these images so you don't have to keep track of previously processed images
});
}

This is not how my code works, since my images are in a MongoDB database and my document has a "resizeImages" boolean property on it, to trigger this to get images to resize. So I don't know if it will work, or what the fs.readdir sends in its files argument on the callback! But you can try :)

With GraphicsMagick, you could also change the format of the image, if you were a stickler and wanted only PNG or JPG files. You can apply filters like motion blur, or transforms like rotation, add text, etc. It is pretty magical...

File System Operations

Somewhat related, how to you simply copy a file in Node.js? I found a method that uses the util.pump method but it didn't work for me. Also, deleting a file in node.js is "unlink", since it will work on symlinks and files. This one did work but I found that I was deleting them too soon, attributed to the non-blocking nature of Node.js, and had to take it out.

And it takes me 20 minutes to figure it out again. This is how you specify a url to a remote repository to a linux box under a user (git's) home directory, using ssh...

git remote add [name] ssh://git@ipaddress/~git/reponame

I usually name them reponame.git.

That should turn the process into a one minute one in the future :)

Is DIRT simple! Consider the code, which searches an item collection for items located near a specific location, designated in longitude/latitude (according to the GeoJSON spec, longitude first, latitude second):
this.findItems = function(db, type, longitude, latitude, index, pageSize, callback){
db.collection("items",function (err, collection){
if (err) throw err;
collection.ensureIndex(["location","2d"], false, function(err){
var search = {}, paging = {};
if(type) search.type = type;
if(longitude != null && latitude != null)
search.location = {"$near" : [parseFloat(longitude),parseFloat(latitude)]};

if (index >= 0 && pageSize >= 0){
paging.skip = index*pageSize;
paging.limit = pageSize;
}

collection.find(search, paging,
function(err,cursor){
cursor.toArray(function(err,items){
callback(items);
}
);
});
});
});
}

It's that simple (minus hours of learning how to do that, scratching my head over stupid errors that I caused but didn't know I was causing [us computer scientists are quick to blame the other guy :) ])

If you can decipher that, good for you. Onto step 3 of a million on my little code project.

I am starting a joint venture with my very good friend, where I am doing the coding, and I decided that I will be doing it in Node.js with a MongoDB backend. I was thinking about why these two technologies, and how I would explain my choices to another techy. I think I have my explanation figured out...

First and foremost, Javascript. I have come to love everything about it! For my side projects, I used to use Java, and wrote a pretty decent web middle tier and rolled my own ORM also. You are witnessing it in action by reading this post. I could make an object like "Book", add properties to it, give them properties in an XML file (a series of them, if you know how Java web apps work ;), and my ORM would create the table, foreign keys, etc. It was particularly magical in how it handled foreign keys and loading referenced objects in one SQL query, knowing which type of join to apply and everything. However, this was all a daunting task, made even more so by the fact that Java allows abstraction to the Nth degree. If I could remember that code, I would be very much more specific on how it worked, but I had an object for connecting to the database, an object in another project for building SQL because I thought I could abstract that out and rewrite it if I had to, and swap in SQL building engines. That was the main cause of pain, I would think "If I just wanted to swap in another X, it would be easy." I initially made plans to have it either go to SQL or XML or JSON, whatever you wanted, and you would just swap in an engine in the config file. It was heavily reflection based :)

So, I've been writing Javascript a lot. Only lately, but before discovering Node.js, have I come to realize its power... anonymous methods and objects, JSON, Functions as first class citizens. Of course there are the libraries, like jQuery, and Google APIs, like maps for instance. There's the shear fact that you don't have to think ahead about every possibility for an object before creating it. Like, my Book object would have an author, title, etc. If later I wanted to add the ISBN or something, in Java I would have to update any IReadable interfaces (well, considering that you could read a cereal box that would undoubtedly NOT have an ISBN, this example is falling apart, but you know what I'm talking about :P ), then update the Book class, update the list to enable searching by an ISBN, etc. Tons of stuff. Javascript:

var Book = function(opt) { for (var i in opt) { this[i] = opt[i]; } }

Imagine I start calling it with
var book = new Book({title: "Brainiac", author: "Ken Jennings", ISBN: "some string of numbers});

I can now just get the ISBN in other places by calling "book.ISBN".

Node.js

I've grown weary of writing server side code in Java and C#. ASP.NET is a CF with its control design, JSF was a CF with its configs and my ginormous web framework that is almost 6 years old now, and I never tried updating past JSF 1.1, so I don't know if it's gotten any better. But Java web development was nuts, you always needed 34 external libraries, most of which came from Apache's Jakarta project (which is awesome though), intimate knowledge of how to set up Tomcat or your favorite application server, you had to know how to write servlets and JSPs, JSTL, JSTL configs, and to read a Catalina.out file. I'm sure I'm forgetting something worth hours of learning...

Node.js is simple. Create a server, attach a listener to the request method. It's so barebones, that requesting anything will not work at all on the server you just created. I researched some libraries for web app development, and I decided, F it, I'm not falling in that trap again. I've dealt with enough code in my life, I could write one. One that takes my favorite things from the frameworks I know, and works on that. It is nearly done...

MongoDB

MongoDB is clearly the only choice for me on Node.js. JSON documents. That should about clear it up, if you were still wondering. If still... imagine we need an ISBN on a book. There's no updating 14 stored procedures that perform CRUD ops on Book to now also include ISBN. No alter table statements... There's simply, Book has ISBN now... db.books.save({title: "Brainiac", author: "Ken Jennings", ISBN: "some number"});

There'll be other books without ISBN, but that's simple... if (book.ISBN != null) (or simply if (book.ISBN) of course). So you think of the basic stuff you need to get off the ground running, and you run. You can run, and you can run fast and recklessly, because if you think of something to add, you put it in. There's very minimal pain, or slowing down, in change.

Node and MongoDB are built for scaling, but I'm not too concerned about that at the moment. Then why, you ask, am I using them? Simply because I do not know them! Although it is 10% for the learning factor, 90% for the cool factor. If it's not cool and I don't know it, then I won't go out of my way to learn it. You might ask, if you're trying to make something awesome, why don't you do it in what you know first, then convert it once you start making money? I'd rather do it in something awesome. Knowing these technologies will be more valuable to me than selling the site to Google for a billion dollars! Ok, that's not true. But if it hits that point, and I didn't do it in Node + MongoDB, then I would not have learned them, and I would not have much reason to NOW, being a billionaire, would I? :P

Oh yeah, Happy Birthday to me today :)

JSON is something to me that is just simple to use in its native environment, that I would never consider writing a parser. I would just try to use it in its natural environment, if I ever have to use it. Well, I found a case where that is not the case!

In my dealings with geocoding locations for clients, I've come across many instances where a limit on the amount of geocoding calls was reached, and I would have to wait until the next day to geocode some more locations. I could write a geocoding mega-program that abstractly geocodes addresses with all of the free services available until it reaches a limit, then moves on to the next service! Fun stuff.

The problem is, with the other geocoders out there, they do not let you specify which format you would like the response to be in. XML is easy to do in C#, however I hadn't researched a JSON parser, so I had tasked myself with writing one from scratch with no previous parsing experience.

Although, it can only have a certain number of syntax elements. {}[],: as far as I know. Quotes ("") contain strings, curlies {} contain objects, squares [] contain arrays. Arrays can contain objects, objects can contain arrays. Objects have to be in field : value pairs. So here's the basic structure:


private Stack syntaxStack;
private Stack tokenStack;

StringBuilder sb = new StringBuilder(); // string builder for catching data

for (loop through json){
switch (char){
case '"':
we're either in a string or just out of a string (set a boolean so we can check in the other cases)
if it's a " preceded by a , add it to the string buffer
break;
case '[':
if we're not in a string
push a '[' onto the syntax stack
push an array token onto the token stack
break;
case '{':
if we're not in a string
push a '{' onto the syntax stack
push an object token onto the token stack
break;
case ']':
if we're not in a string
Get the last value in the array, if there is one
( it could have also been an array of arrays, and we're closing the outer array, so there won't be a value)
add to the children of the last token in the token stack
pop from each stack, we're out of the current array
break;
case '}':
if we're not in a string and we're in an object
get the last value in the object, if there is one
set the value in the last object
pop from each stack, we are out of that object
case ',':
if we're not in a string
if we're in an object, a value was just specified. if it's a string value, set the last field's value to the data in the string builder
clear the string buffer
break;
case ':':
if we're not in a string
we should be in an object, and the previous string was the field, so create a field token and add it to the current node
clear the string buffer
break;
default:
append the character to the data string buffer
}
}

bool InArray
= this.syntaxStack.Peek() == '['

bool InObject
= this.syntaxStack.Peek() == '{'


Here is the Visual Studio 2008 project with C# code for parsing your own JSON. I think mine looks decent compared to others out there