Roo/data/HttpProxy.js

/*
 * Based on:
 * Ext JS Library 1.1.1
 * Copyright(c) 2006-2007, Ext JS, LLC.
 *
 * Originally Released Under LGPL - original licence link has changed is not relivant.
 *
 * Fork - LGPL
 * <script type="text/javascript">
 */
/**
 * @class Roo.data.HttpProxy
 * @extends Roo.data.DataProxy
 * An implementation of {@link Roo.data.DataProxy} that reads a data object from an {@link Roo.data.Connection} object
 * configured to reference a certain URL.<br><br>
 * <p>
 * <em>Note that this class cannot be used to retrieve data from a domain other than the domain
 * from which the running page was served.<br><br>
 * <p>
 * For cross-domain access to remote data, use an {@link Roo.data.ScriptTagProxy}.</em><br><br>
 * <p>
 * Be aware that to enable the browser to parse an XML document, the server must set
 * the Content-Type header in the HTTP response to "text/xml".
 * @constructor
 * @param {Object} conn Connection config options to add to each request (e.g. {url: 'foo.php'} or
 * an {@link Roo.data.Connection} object.  If a Connection config is passed, the singleton {@link Roo.Ajax} object
 * will be used to make the request.
 */
Roo.data.HttpProxy = function(conn){
    Roo.data.HttpProxy.superclass.constructor.call(this);
    // is conn a conn config or a real conn?
    this.conn = conn;
    this.useAjax = !conn || !conn.events;

};

Roo.extend(Roo.data.HttpProxy, Roo.data.DataProxy, {
    // thse are take from connection...

    /**
     * @cfg {String} url (Optional) The default URL to be used for requests to the server. (defaults to undefined)
     */
    /**
     * @cfg {Object} extraParams (Optional) An object containing properties which are used as
     * extra parameters to each request made by this object. (defaults to undefined)
     */
    /**
     * @cfg {Object} defaultHeaders (Optional) An object containing request headers which are added
     *  to each request made by this object. (defaults to undefined)
     */
    /**
     * @cfg {String} method (Optional) The default HTTP method to be used for requests. (defaults to undefined; if not set but parms are present will use POST, otherwise GET)
     */
    /**
     * @cfg {Number} timeout (Optional) The timeout in milliseconds to be used for requests. (defaults to 30000)
     */
     /**
     * @cfg {Boolean} autoAbort (Optional) Whether this request should abort any pending requests. (defaults to false)
     * @type Boolean
     */


    /**
     * @cfg {Boolean} disableCaching (Optional) True to add a unique cache-buster param to GET requests. (defaults to true)
     * @type Boolean
     */
    /**
     * Return the {@link Roo.data.Connection} object being used by this Proxy.
     * @return {Connection} The Connection object. This object may be used to subscribe to events on
     * a finer-grained basis than the DataProxy events.
     */
    getConnection : function(){
        return this.useAjax ? Roo.Ajax : this.conn;
    },

    /**
     * Load data from the configured {@link Roo.data.Connection}, read the data object into
     * a block of Roo.data.Records using the passed {@link Roo.data.DataReader} implementation, and
     * process that block using the passed callback.
     * @param {Object} params An object containing properties which are to be used as HTTP parameters
     * for the request to the remote server.
     * @param {Roo.data.DataReader} reader The Reader object which converts the data
     * object into a block of Roo.data.Records.
     * @param {Function} callback The function into which to pass the block of Roo.data.Records.
     * The function must be passed <ul>
     * <li>The Record block object</li>
     * <li>The "arg" argument from the load function</li>
     * <li>A boolean success indicator</li>
     * </ul>
     * @param {Object} scope The scope in which to call the callback
     * @param {Object} arg An optional argument which is passed to the callback as its second parameter.
     */
    load : function(params, reader, callback, scope, arg){
        if(this.fireEvent("beforeload", this, params) !== false){
            var  o = {
                params : params || {},
                request: {
                    callback : callback,
                    scope : scope,
                    arg : arg
                },
                reader: reader,
                callback : this.loadResponse,
                scope: this
            };
            if(this.useAjax){
                Roo.applyIf(o, this.conn);
                if(this.activeRequest){
                    Roo.Ajax.abort(this.activeRequest);
                }
                this.activeRequest = Roo.Ajax.request(o);
            }else{
                this.conn.request(o);
            }
        }else{
            callback.call(scope||this, null, arg, false);
        }
    },

    // private
    loadResponse : function(o, success, response){
        delete this.activeRequest;
        if(!success){
            this.fireEvent("loadexception", this, o, response);
            o.request.callback.call(o.request.scope, null, o.request.arg, false);
            return;
        }
        var result;
        try {
            result = o.reader.read(response);
        }catch(e){
            this.fireEvent("loadexception", this, o, response, e);
            o.request.callback.call(o.request.scope, null, o.request.arg, false);
            return;
        }

        this.fireEvent("load", this, o, o.request.arg);
        o.request.callback.call(o.request.scope, result, o.request.arg, true);
    },

    // private
    update : function(dataSet){

    },

    // private
    updateResponse : function(dataSet){

    }
});