yui-pathogen-encoder/example/node_modules/express-yui/lib/origin.js

Enables pathogen encoding in YUI Loader

/*
 * Copyright (c) 2013, Yahoo! Inc.  All rights reserved.
 * Copyrights licensed under the New BSD License.
 * See the accompanying LICENSE file for terms.
 */

/*jslint node:true, nomen: true */

/**
The `express-yui.origin` extension that provides a set of features
to mutate the express app into an origin server for yui
modules and static assets.

@module yui
@submodule origin
**/

'use strict';

var libpath    = require('path'),
    utils      = require('./utils');

/**
The `express-yui.origin` extension that provides some basic configuration
that will facilitate the configuration of YUI Core modules and other
groups to be served from the express app in a form of origin server.

This is not recommended for production and instead you should use the
`cdn` module, but it is a very useful feature for development of offline
applications.

    var express = require('express'),
        expyui = require('express-yui'),
        app = express();

    expyui.extend(app);
    // getting YUI Core modules from the app origin.
    app.yui.setCoreFromAppOrigin();
    // registering a group `app` based on a folder generated by `shifter` module
    app.yui.registerGroup('app', '/path/to/foo/yui-build');
    app.use(expyui.static());

@class origin
@static
@uses utils, *path
@extensionfor yui
*/
module.exports = {

    /**
    Set YUI Core Modules from the same origin as to where the application
    is hosted.

    Here is an example on how to use it:

        app.yui.setCoreFromAppOrigin({});

    @method setCoreFromAppOrigin
    @public
    @param {Object} loaderConfig optional loader configuration for the core
    @chainable
    **/
    setCoreFromAppOrigin: function (loaderConfig) {

        var groupDefaultBase = this._app.set('yui default base') || "/{{groupDir}}/",
            groupDefaultRoot = this._app.set('yui default root') || "/{{groupDir}}/",
            comboConfig = this._app.set('yui combo config') || utils.DEFAULT_COMBO_CONFIG,
            config = this.config(),
            yuiDir = 'yui-' + this.version;

        loaderConfig = loaderConfig || {};

        loaderConfig = utils.extend(config, comboConfig, {
            base: groupDefaultBase,
            root: groupDefaultRoot
        }, loaderConfig);

        // fixed base and root for this group
        // replace groupName and groupDirname
        loaderConfig.base = loaderConfig.base.replace("{{groupDir}}", yuiDir);
        loaderConfig.root = loaderConfig.root.replace("{{groupDir}}", yuiDir);

        return this;

    },

    /**
    Set a custom loader configuration for the group.

    Here is an example of how to use it.

        app.yui.applyGroupConfig('app', {
            maxURLLength: 2048,
            comboBase: "/combo?"
            comboSep: "&"
        });

    @method applyGroupConfig
    @public
    @param {String} groupName the name of the group used by loader.
    @param {Object} loaderConfig custom loader configuration
    for the group.
    @chainable
    **/
    applyGroupConfig: function (groupName, loaderConfig) {

        var config = this.config();

        loaderConfig = loaderConfig || {};
        // setting up the group base config if needed
        config.groups = config.groups || {};
        config.groups[groupName] = config.groups[groupName] || {};

        config.groups[groupName] = utils.extend(config.groups[groupName], loaderConfig);

        return this;

    },

    /**
    Register a group and its modules by analyzing the meta file and defining the
    group configuration for the loader. Groups can be served from origin app or
    from CDN by calling `applyGroupConfig` or by setting `yui default base`,
    `yui default root` and `yui combo config` thru `app.set()`.

    Here is an example on how to use it, assuming that the YUI metadata are
    located in the `build` directory under the app root.

        app.yui.registerGroup('app', __dirname + '/build');

    @method registerGroup
    @public
    @param {String} groupName the name of the group used by loader.
    @param {String} groupRoot filesystem path for the group. This will be used to
    analyze all modules in the group.
    @param {String} metaFile optional filesystem path for the yui module that holds
    the metas for the group. Default value: `<groupRoot>/<groupName>/<groupName>.js`
    @chainable
    **/
    registerGroup: function (groupName, groupRoot, metaFile) {

        var groupDefaultBase = this._app.set('yui default base') || "/{{groupDir}}/",
            groupDefaultRoot = this._app.set('yui default root') || "/{{groupDir}}/",
            comboConfig = this._app.set('yui combo config') || utils.DEFAULT_COMBO_CONFIG,
            group,
            groupConfig,
            config,
            groupDir = libpath.basename(groupRoot);

        metaFile = metaFile || libpath.join(groupRoot, groupName, groupName + '.js');

        // collect the group information from the meta file
        group = this.getGroupConfig(metaFile);

        if (!group) {
            throw new Error("Invalid meta file [" + metaFile + "], " +
                "it contains no group.");
        }

        if (groupName !== group.groupName) {
            throw new Error("Mismatch between the groupName [" + groupName +
                "] and the group registered in [" + metaFile + "].");
        }

        config = this.config();
        config.groups = config.groups || {};

        // setting up the default group config
        groupConfig = config.groups[groupName] = utils.extend({
            base: groupDefaultBase,
            root: groupDefaultRoot,
            // inherit combine
            combine: config.hasOwnProperty('combine') ? config.combine : true,
            // inherit filter
            filter: config.hasOwnProperty('filter') ? config.filter : 'min'
        }, comboConfig, config.groups[groupName] || {});

        // replace groupName and groupDirname
        groupConfig.base = groupConfig.base.replace("{{groupDir}}", groupDir);
        groupConfig.root = groupConfig.root.replace("{{groupDir}}", groupDir);

        // storing the root path to the group in case we
        // need it later to server the group from origin server
        this._groupFolderMap = this._groupFolderMap || {};
        this._groupFolderMap[groupName] = groupRoot;

        // add the meta module into the core structure
        // to make sure it gets attached to Y upfront
        this.addModuleToSeed(group.moduleName, groupName);

        return this;

    }

};