ScriptTagProxy.html | searchcode

/tine20/library/ExtJS/docs/source/ScriptTagProxy.html

https://gitlab.com/rsilveira1987/Expresso
HTML | 309 lines | 287 code | 22 blank | 0 comment | 0 complexity | ae515d9374d9e7ccca75bd4af45b4112 MD5 | raw file

<html>

<head>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />    

  <title>The source code</title>

    <link href="../resources/prettify/prettify.css" type="text/css" rel="stylesheet" />

    <script type="text/javascript" src="../resources/prettify/prettify.js"></script>

</head>

<body  onload="prettyPrint();">

    <pre class="prettyprint lang-js"><div id="cls-Ext.data.ScriptTagProxy"></div>/**

 * @class Ext.data.ScriptTagProxy

 * @extends Ext.data.DataProxy

 * An implementation of Ext.data.DataProxy that reads a data object from a URL which may be in a domain

 * other than the originating domain of the running page.<br>

 * <p>

 * <b>Note that if you are retrieving data from a page that is in a domain that is NOT the same as the originating domain

 * of the running page, you must use this class, rather than HttpProxy.</b><br>

 * <p>

 * The content passed back from a server resource requested by a ScriptTagProxy <b>must</b> be executable JavaScript

 * source code because it is used as the source inside a &lt;script> tag.<br>

 * <p>

 * In order for the browser to process the returned data, the server must wrap the data object

 * with a call to a callback function, the name of which is passed as a parameter by the ScriptTagProxy.

 * Below is a Java example for a servlet which returns data for either a ScriptTagProxy, or an HttpProxy

 * depending on whether the callback name was passed:

 * <p>

 * <pre><code>

boolean scriptTag = false;

String cb = request.getParameter("callback");

if (cb != null) {

    scriptTag = true;

    response.setContentType("text/javascript");

} else {

    response.setContentType("application/x-json");

}

Writer out = response.getWriter();

if (scriptTag) {

    out.write(cb + "(");

}

out.print(dataBlock.toJsonString());

if (scriptTag) {

    out.write(");");

}

</code></pre>

 * <p>Below is a PHP example to do the same thing:</p><pre><code>

$callback = $_REQUEST['callback'];



// Create the output object.

$output = array('a' => 'Apple', 'b' => 'Banana');



//start output

if ($callback) {

    header('Content-Type: text/javascript');

    echo $callback . '(' . json_encode($output) . ');';

} else {

    header('Content-Type: application/x-json');

    echo json_encode($output);

}

</code></pre>

 * <p>Below is the ASP.Net code to do the same thing:</p><pre><code>

String jsonString = "{success: true}";

String cb = Request.Params.Get("callback");

String responseString = "";

if (!String.IsNullOrEmpty(cb)) {

    responseString = cb + "(" + jsonString + ")";

} else {

    responseString = jsonString;

}

Response.Write(responseString);

</code></pre>

 *

 * @constructor

 * @param {Object} config A configuration object.

 */

Ext.data.ScriptTagProxy = function(config){

    Ext.apply(this, config);



    Ext.data.ScriptTagProxy.superclass.constructor.call(this, config);



    this.head = document.getElementsByTagName("head")[0];



    <div id="event-Ext.data.ScriptTagProxy-loadexception"></div>/**

     * @event loadexception

     * <b>Deprecated</b> in favor of 'exception' event.

     * Fires if an exception occurs in the Proxy during data loading.  This event can be fired for one of two reasons:

     * <ul><li><b>The load call timed out.</b>  This means the load callback did not execute within the time limit

     * specified by {@link #timeout}.  In this case, this event will be raised and the

     * fourth parameter (read error) will be null.</li>

     * <li><b>The load succeeded but the reader could not read the response.</b>  This means the server returned

     * data, but the configured Reader threw an error while reading the data.  In this case, this event will be

     * raised and the caught error will be passed along as the fourth parameter of this event.</li></ul>

     * Note that this event is also relayed through {@link Ext.data.Store}, so you can listen for it directly

     * on any Store instance.

     * @param {Object} this

     * @param {Object} options The loading options that were specified (see {@link #load} for details).  If the load

     * call timed out, this parameter will be null.

     * @param {Object} arg The callback's arg object passed to the {@link #load} function

     * @param {Error} e The JavaScript Error object caught if the configured Reader could not read the data.

     * If the remote request returns success: false, this parameter will be null.

     */

};



Ext.data.ScriptTagProxy.TRANS_ID = 1000;



Ext.extend(Ext.data.ScriptTagProxy, Ext.data.DataProxy, {

    <div id="cfg-Ext.data.ScriptTagProxy-url"></div>/**

     * @cfg {String} url The URL from which to request the data object.

     */

    <div id="cfg-Ext.data.ScriptTagProxy-timeout"></div>/**

     * @cfg {Number} timeout (optional) The number of milliseconds to wait for a response. Defaults to 30 seconds.

     */

    timeout : 30000,

    <div id="cfg-Ext.data.ScriptTagProxy-callbackParam"></div>/**

     * @cfg {String} callbackParam (Optional) The name of the parameter to pass to the server which tells

     * the server the name of the callback function set up by the load call to process the returned data object.

     * Defaults to "callback".<p>The server-side processing must read this parameter value, and generate

     * javascript output which calls this named function passing the data object as its only parameter.

     */

    callbackParam : "callback",

    <div id="cfg-Ext.data.ScriptTagProxy-nocache"></div>/**

     *  @cfg {Boolean} nocache (optional) Defaults to true. Disable caching by adding a unique parameter

     * name to the request.

     */

    nocache : true,



    <div id="method-Ext.data.ScriptTagProxy-doRequest"></div>/**

     * HttpProxy implementation of DataProxy#doRequest

     * @param {String} action

     * @param {Ext.data.Record/Ext.data.Record[]} rs If action is <tt>read</tt>, rs will be null

     * @param {Object} params An object containing properties which are to be used as HTTP parameters

     * for the request to the remote server.

     * @param {Ext.data.DataReader} reader The Reader object which converts the data

     * object into a block of Ext.data.Records.

     * @param {Function} callback The function into which to pass the block of Ext.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 (<code>this</code> reference) in which the callback function is executed. Defaults to the browser window.

     * @param {Object} arg An optional argument which is passed to the callback as its second parameter.

     */

    doRequest : function(action, rs, params, reader, callback, scope, arg) {

        var p = Ext.urlEncode(Ext.apply(params, this.extraParams));



        var url = this.buildUrl(action, rs);

        if (!url) {

            throw new Ext.data.Api.Error('invalid-url', url);

        }

        url = Ext.urlAppend(url, p);



        if(this.nocache){

            url = Ext.urlAppend(url, '_dc=' + (new Date().getTime()));

        }

        var transId = ++Ext.data.ScriptTagProxy.TRANS_ID;

        var trans = {

            id : transId,

            action: action,

            cb : "stcCallback"+transId,

            scriptId : "stcScript"+transId,

            params : params,

            arg : arg,

            url : url,

            callback : callback,

            scope : scope,

            reader : reader

        };

        window[trans.cb] = this.createCallback(action, rs, trans);

        url += String.format("&{0}={1}", this.callbackParam, trans.cb);

        if(this.autoAbort !== false){

            this.abort();

        }



        trans.timeoutId = this.handleFailure.defer(this.timeout, this, [trans]);



        var script = document.createElement("script");

        script.setAttribute("src", url);

        script.setAttribute("type", "text/javascript");

        script.setAttribute("id", trans.scriptId);

        this.head.appendChild(script);



        this.trans = trans;

    },



    // @private createCallback

    createCallback : function(action, rs, trans) {

        var self = this;

        return function(res) {

            self.trans = false;

            self.destroyTrans(trans, true);

            if (action === Ext.data.Api.actions.read) {

                self.onRead.call(self, action, trans, res);

            } else {

                self.onWrite.call(self, action, trans, res, rs);

            }

        };

    },

    <div id="method-Ext.data.ScriptTagProxy-onRead"></div>/**

     * Callback for read actions

     * @param {String} action [Ext.data.Api.actions.create|read|update|destroy]

     * @param {Object} trans The request transaction object

     * @param {Object} res The server response

     * @protected

     */

    onRead : function(action, trans, res) {

        var result;

        try {

            result = trans.reader.readRecords(res);

        }catch(e){

            // @deprecated: fire loadexception

            this.fireEvent("loadexception", this, trans, res, e);



            this.fireEvent('exception', this, 'response', action, trans, res, e);

            trans.callback.call(trans.scope||window, null, trans.arg, false);

            return;

        }

        if (result.success === false) {

            // @deprecated: fire old loadexception for backwards-compat.

            this.fireEvent('loadexception', this, trans, res);



            this.fireEvent('exception', this, 'remote', action, trans, res, null);

        } else {

            this.fireEvent("load", this, res, trans.arg);

        }

        trans.callback.call(trans.scope||window, result, trans.arg, result.success);

    },

    <div id="method-Ext.data.ScriptTagProxy-onWrite"></div>/**

     * Callback for write actions

     * @param {String} action [Ext.data.Api.actions.create|read|update|destroy]

     * @param {Object} trans The request transaction object

     * @param {Object} res The server response

     * @protected

     */

    onWrite : function(action, trans, response, rs) {

        var reader = trans.reader;

        try {

            // though we already have a response object here in STP, run through readResponse to catch any meta-data exceptions.

            var res = reader.readResponse(action, response);

        } catch (e) {

            this.fireEvent('exception', this, 'response', action, trans, res, e);

            trans.callback.call(trans.scope||window, null, res, false);

            return;

        }

        if(!res.success === true){

            this.fireEvent('exception', this, 'remote', action, trans, res, rs);

            trans.callback.call(trans.scope||window, null, res, false);

            return;

        }

        this.fireEvent("write", this, action, res.data, res, rs, trans.arg );

        trans.callback.call(trans.scope||window, res.data, res, true);

    },



    // private

    isLoading : function(){

        return this.trans ? true : false;

    },



    <div id="method-Ext.data.ScriptTagProxy-abort"></div>/**

     * Abort the current server request.

     */

    abort : function(){

        if(this.isLoading()){

            this.destroyTrans(this.trans);

        }

    },



    // private

    destroyTrans : function(trans, isLoaded){

        this.head.removeChild(document.getElementById(trans.scriptId));

        clearTimeout(trans.timeoutId);

        if(isLoaded){

            window[trans.cb] = undefined;

            try{

                delete window[trans.cb];

            }catch(e){}

        }else{

            // if hasn't been loaded, wait for load to remove it to prevent script error

            window[trans.cb] = function(){

                window[trans.cb] = undefined;

                try{

                    delete window[trans.cb];

                }catch(e){}

            };

        }

    },



    // private

    handleFailure : function(trans){

        this.trans = false;

        this.destroyTrans(trans, false);

        if (trans.action === Ext.data.Api.actions.read) {

            // @deprecated firing loadexception

            this.fireEvent("loadexception", this, null, trans.arg);

        }



        this.fireEvent('exception', this, 'response', trans.action, {

            response: null,

            options: trans.arg

        });

        trans.callback.call(trans.scope||window, null, trans.arg, false);

    },



    // inherit docs

    destroy: function(){

        this.abort();

        Ext.data.ScriptTagProxy.superclass.destroy.call(this);

    }

});</pre>    

</body>

</html>