Depender: A MooTools Dependency Loader

This application generates concatenated libraries from multiple JavaScript files based on their dependencies and the files you require. It assumes that you have formatted your libraries in the way that MooTools is organized, though it does not require MooTools itself to operate.

Configuration

Included in this distribution is a file named "config_example.json" which, if copied to "config.json" will put this app into it's default mode. The values in the config.json are as follows:

• copyright - A string prepended to the beginning of all files built by the app. Defaults to the copyrights for the default libraries (MooTools Core & MooTools More)

• compression - The default compression to use. Values can be "yui", "jsmin", or "none" - defaults to "yui"; see compression section below for more details on compression.

• available_compressions - Supported compression types - defaults to both "yui", and "jsmin"; not all systems are set up to allow java executables at the command line (as on certain low-end hosting providers) so you may wish to disable yui.

• cache - Enables/disables caching of compressed files. Defaults to "true". See section below on caching for more details.

• libs - an object pointing to each library that the builder should support. Each entry has a setting for "scripts" which points to the directory that contains scripts.json. From the example file:

    "libs": {
    	"mootools-core": {
    		"scripts": "libs/core/Source"
    	},
    	"mootools-more": {
    		"scripts": "libs/more/Source"
    	}
    }
  

Initialization

The application ships with two git submodule settings - one for the most recent, stable release of MooTools Core and another for MooTools More. Thought the application does not require these to function, most people will wish to include these. To initialize these libraries you must execute at the command line:

git submodule update --init

This will download the libraries. Copy config_example.json over to config.json and the application is ready to run. If you do not have git installed on your computer, you can simply download the MooTools Core and MooTools More libraries and unzip them into libs/core and libs/more.

Note that the outputs directory must be writable by your web server.

Adding Libraries

Additional libraries can be easily added to the system by dropping their contents into the libs/ directory and editing the config file. You can use git submodules to track specific branches of external repositories or you can track a working branch using something like crepo. Each library must have a scripts.json file that notes dependencies. I suggest the Moo-ish Template as a good place to start.

Compression

The application includes two compression libraries: jsmin which is a native php library and yui which is a java command line utility. Whenever a library is built, the uncompressed version of the file is saved to disk. If compression is enabled or requested the file is run through the compressor and also written to disk.

Some systems may not be able to run the YUI compressor. For this purpose, there is another setting in the config file for "available_compressions" which is an array of the compressions you wish to support. It defaults to [yui, jsmin]. Setting this value to an empty array will disable compression support entirely.

Outputs

Each requested file is output into it's own directory, named as the md5 hash of the file's contents (the list of file names, not the actual concatenated code). Each file, whether compressed or not, is given a header that looks something like this:

//<copyright as defined in config.json>

//Contents: Core, Hash, Number, Function, String, Array, etc.

//This lib: http://localhost/depender/build.php?requireLibs=mootools-core

From the header of the file you have the url needed to regenerate it as well as an inventory of the individual scripts included.

In addition to these headers, each directory has a file entitled contents.json which has an object that lists the contents of the file. This file is not really intended to be used by you, but it may be helpful if you wish to integrate another system with the output.

Caching

The setting in config.json for caching controls whether libraries are rebuilt every time they are requested. If set to true, the default, every request for a set of requirements will check to see if the library has been built before and return the contents of that library if true. Disabling caching is very useful for development.

Requests and Query String Values

To request a library, you can specify four arguments for the contents of the file:

• require - a comma separated list of files to require; can also be specified in the php style as "require[]=foo&require[]=bar"
• requireLibs - a comma separated list of libraries to require - these are the names defined in our congfig.json in the libs section. So, for example, requireLibs=mootools-core,mootools-more using the default config would include both the complete inventories of MooTools Core and More. This can also be specified as a comma separated list or the php style (requireLibs[]=mootools-core&requireLibs[]=mootools-more).
• exclude - exactly like the require value, except it's a list of files to exclude. This is useful if you have already loaded some scripts and now you require another. You can specify the scripts you already have and the one you now need, and the library will return only those you do not have.
• excludeLibs - just like the exclude option but instead you can specify entire libraries.

Additional Query String Values

In addition to the four values you can specify for the contents of the file, you can also override the default settings on the server for compression and caching.

• cache - if set to true you'll be returned a cached version of the script even if the server is set to false and vice versa.
• compression - you'll be returned the compression type you specify regardless of the server default. Note that if you specify a compression type that the server does not allow, you'll be returned which ever one it does. If it does not support compression at all, you will not be returned a compressed file. You can also specify "none" which is useful for development and debugging.

File System Caching vs Other Options

Reading these files from the disk is not the best way to cache them. Every request still has to compute which items you need and check the local disk to see if the file exists. If it does php reads that file and sends it to the browser. There are other caching systems that are far more performant (such as memcached for example) that you may wish to consider. Unless you are using the system to lazy load content, you might consider downloading the built file and linking to it directly (just as if you'd downloaded it from mootools.net for example). For sites that do not have to support excessively large volumes of traffic you'll probably be fine just including the scripts directly from the builder (i.e. a script tag that links to "/depender/build.php?requireLibs=mootools-core").

The Builder Interface

The application ships with an HTML interface that allows you to pick and choose which files you wish to include in your download. You can easily specify your dependencies and see which files will be included with them. This interface basically just serves to help you construct the url for the library but also has a "Download" button to actually get the file if you want to save it. It can also be used to distribute your own plugins and files if you wish to share them.