August 2011 - Posts

As some of you might know, with the release of Node version 0.5.2, there is now support for Windows. It’s a single executable “node.exe” that you need to start using node on your machine, and you can get it from this location.

Express is a Sinatra inspired web development framework for Node. You can find more information about this framework here.

Once you download node in your system, you need to setup an optional environment variable “NODE_PATH”, which points to the root path or location that Node will use to resolve the external module references. A module in Node represents an unit of code reuse, pretty similar to a library or an assembly in .NET, but it’s not something binary, it is just JavaScript code. You can also optionally set the node executable path in the “PATH” environmental variable to run the exe from any location.

In my case, I created the following structure on my disk for running Node.

d:>

----> NodeJs

------> Node.exe

------> Applications

“NODE_PATH” and “PATH” both points to the folder “NodeJS” on my “d:” drive. All the applications or samples will be deployed in the “Applications” folder.

In the Linux world, Node also comes with a very useful package manager “NPM” that automatically resolves external module dependencies for you.  As analogy with other platforms like Ruby or .NET, “NPM” would be equivalent to Ruby GEMS or NuGet.

Unfortunately, “NPM” is still not ready for being used on Windows, there are some technical details that need to be addressed to migrate the current implementation to windows. Good news is that Jeroen Janssen has created a similar implementation in Python so you can run it in windows. The name of this implementation is “ryppi” and you can get it from this github repository. It’s a single Phyton script “ryppi.py” that currently works with Python 2.X only. If you have Python 2.x already installed on your system, you can run the script as follow to resolve an external dependency “python ryppi install <PACKAGE_NAME>”.

In the case of “Express”, you can run  “python ryppi install Express” from the location where you set the “NODE_PATH” variable. After running the command, you should be able to see a new folder “node_modules” in that location, and an “express” folder inside of it. That’s the only package you need to run the “Express” core, but you also might want to download “jade” and “saas” for using the Jade View Engine and the SAAS engine respectively.

In addition to the “Express” core library, there is an node application you can use to setup the initial folder structure for your web applications. The “Express” application is available under “node_modules/express/bin/express”, and you can run it with node itself. Bad news is that this application does not run on windows because it uses the “child_process” module, which is not currently supported on windows. I modified that application to get rid of the “child_process” module and use all the functionality available in windows. This updated version is available to download from here.

If you replace the version in “node_modules/express/bin/express” by the one I updated, you should able to run it with node as follow “node.exe ./node_modules/express/bin/express –help”. That will show the help instructions to setup a new web application. A new web application with all the defaults can be created by just passing a name to that “express” application, “node.exe ./node_modules/express/bin/express mywebapp”. One thing to have in mind is that the application will be created as a new folder in the current location, so you might want to run it from “NodeJs/Applications” if you are planning to have the web application in there.

The command will generate a new folder “mywebapp” with all the boilerplate structure you need to run a web application from scratch.  The folder structure looks like this,

- public (contains all the JavaScript, images and stylesheets that make up your site)

- views (contains all the views)

- app.js (the root application)

You can start the web application by running “node app”, and that’s it, you have your first “express” application running on windows Smile.

Posted by cibrax | 1 comment(s)
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