post_4 - cs2

gistfile1.js

/*!
 * Javascript Pattern for Rest Service API’s
 * http://www.chriscouchoud.com/
 * 
 * Dual licensed under the MIT and GPL licenses.
 */

service = {

    baseURL : "http://www.yourrestapi.com",

    /**
        Delegate for the jquery.ajax call that provides for some extended pre/post call functionality.

        @param {String} descriptor type of service request to make
        @param {Object} resource data object used to map the ajax call
        @param {Object} [options] optional jquery ajax options object that can be used to define
                                  custom parameters for the ajax request. This often will include
                                  specific success and error handlers specific to the call you are
                                  making and probably some data that you went sent along in the
                                  request.

     */

    create : function(descriptor, resource, options) {

        // match up the service definition
        var def = serviceDefinitions[descriptor];
        /**
            udpate the default options on the jQuery ajax object using
            the values defined in the definition
        */
        // here we map the resource to the url defined in the definition
        options.url = this._mapResourceToUrl(def.url, resource);
        options.type = def.type || "GET";
        options.dataType = def.dataType || "json";
        options.contentType = def.contentType || "application/x-www-form-urlencoded";

        // make the ajax call
        $.ajax(options);
    },

    /**
            Matches {PROPERTY_NAME} in the url with the corressponding 
            property value in resource
            
            property value can be a String, Number, or Function that returns
            a string
            
            @param {Object} resource object with properties to map
            @param {String} url string with 'foo/{PROPERTY_NAME}/' format

     */
    _mapResourceToUrl : function(resource, url) {
        url = this.baseURL + url;
        return url.replace(/{([^{}]*)}/g,
                        function (a, b) {
                                var r = resource[b],
                                    value = r;
                                
                                // special handling numbers and functions
                                if(typeof r === 'number') {
                                    value = r + "";
                                }
                                else if(typeof r === 'function') {
                                    // pass in resource as the scope
                                    value = r.call(resource);
                                 }   
                                // ensure a string is returned
                                return (typeof value === 'string') ? value : a; 
                        });
    }
}