if(!dojo._hasResource["dojo.io.script"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code. dojo._hasResource["dojo.io.script"] = true; dojo.provide("dojo.io.script"); /*===== dojo.io.script.__ioArgs = function(kwArgs){ // summary: // All the properties described in the dojo.__ioArgs type, apply to this // type as well, EXCEPT "handleAs". It is not applicable to // dojo.io.script.get() calls, since it is implied by the usage of // "callbackParamName" (response will be a JSONP call returning JSON) // or "checkString" (response is pure JavaScript defined in // the body of the script that was attached). The following additional // properties are allowed for dojo.io.script.get(): // callbackParamName: String // The URL parameter name that indicates the JSONP callback string. // For instance, when using Yahoo JSONP calls it is normally, // callbackParamName: "callback". For AOL JSONP calls it is normally // callbackParamName: "c". // checkString: String // A string of JavaScript that when evaluated like so: // "typeof(" + checkString + ") != 'undefined'" // being true means that the script fetched has been loaded. // Do not use this if doing a JSONP type of call (use callbackParamName instead). // frameDoc: Document. // The Document object for a child iframe. If this is passed in, the script // will be attached to that document. This can be helpful in some comet long-polling // scenarios with Firefox and Opera. } =====*/ dojo.io.script = { get: function(/*dojo.io.script.__ioArgs*/args){ // summary: // sends a get request using a dynamically created script tag. var dfd = this._makeScriptDeferred(args); var ioArgs = dfd.ioArgs; dojo._ioAddQueryToUrl(ioArgs); this.attach(ioArgs.id, ioArgs.url, args.frameDoc); dojo._ioWatch(dfd, this._validCheck, this._ioCheck, this._resHandle); return dfd; }, attach: function(/*String*/id, /*String*/url, /*Document?*/frameDocument){ // summary: // creates a new tag pointing to the specified URL and // adds it to the document. // description: // Attaches the script element to the DOM. Use this method if you // just want to attach a script to the DOM and do not care when or // if it loads. var doc = (frameDocument || dojo.doc); var element = doc.createElement("script"); element.type = "text/javascript"; element.src = url; element.id = id; doc.getElementsByTagName("head")[0].appendChild(element); }, remove: function(/*String*/id){ //summary: removes the script element with the given id. dojo._destroyElement(dojo.byId(id)); //Remove the jsonp callback on dojo.io.script, if it exists. if(this["jsonp_" + id]){ delete this["jsonp_" + id]; } }, _makeScriptDeferred: function(/*Object*/args){ //summary: // sets up a Deferred object for an IO request. var dfd = dojo._ioSetArgs(args, this._deferredCancel, this._deferredOk, this._deferredError); var ioArgs = dfd.ioArgs; ioArgs.id = dojo._scopeName + "IoScript" + (this._counter++); ioArgs.canDelete = false; //Special setup for jsonp case if(args.callbackParamName){ //Add the jsonp parameter. ioArgs.query = ioArgs.query || ""; if(ioArgs.query.length > 0){ ioArgs.query += "&"; } ioArgs.query += args.callbackParamName + "=" + (args.frameDoc ? "parent." : "") + "dojo.io.script.jsonp_" + ioArgs.id + "._jsonpCallback"; //Setup the Deferred to have the jsonp callback. ioArgs.canDelete = true; dfd._jsonpCallback = this._jsonpCallback; this["jsonp_" + ioArgs.id] = dfd; } return dfd; // dojo.Deferred }, _deferredCancel: function(/*Deferred*/dfd){ //summary: canceller function for dojo._ioSetArgs call. //DO NOT use "this" and expect it to be dojo.io.script. dfd.canceled = true; if(dfd.ioArgs.canDelete){ dojo.io.script._deadScripts.push(dfd.ioArgs.id); } }, _deferredOk: function(/*Deferred*/dfd){ //summary: okHandler function for dojo._ioSetArgs call. //DO NOT use "this" and expect it to be dojo.io.script. //Add script to list of things that can be removed. if(dfd.ioArgs.canDelete){ dojo.io.script._deadScripts.push(dfd.ioArgs.id); } if(dfd.ioArgs.json){ //Make sure to *not* remove the json property from the //Deferred, so that the Deferred can still function correctly //after the response is received. return dfd.ioArgs.json; }else{ //FIXME: cannot return the dfd here, otherwise that stops //the callback chain in Deferred. So return the ioArgs instead. //This doesn't feel right. return dfd.ioArgs; } }, _deferredError: function(/*Error*/error, /*Deferred*/dfd){ //summary: errHandler function for dojo._ioSetArgs call. if(dfd.ioArgs.canDelete){ //DO NOT use "this" and expect it to be dojo.io.script. if(error.dojoType == "timeout"){ //For timeouts, remove the script element immediately to //avoid a response from it coming back later and causing trouble. dojo.io.script.remove(dfd.ioArgs.id); }else{ dojo.io.script._deadScripts.push(dfd.ioArgs.id); } } console.debug("dojo.io.script error", error); return error; }, _deadScripts: [], _counter: 1, _validCheck: function(/*Deferred*/dfd){ //summary: inflight check function to see if dfd is still valid. //Do script cleanup here. We wait for one inflight pass //to make sure we don't get any weird things by trying to remove a script //tag that is part of the call chain (IE 6 has been known to //crash in that case). var _self = dojo.io.script; var deadScripts = _self._deadScripts; if(deadScripts && deadScripts.length > 0){ for(var i = 0; i < deadScripts.length; i++){ //Remove the script tag _self.remove(deadScripts[i]); } dojo.io.script._deadScripts = []; } return true; }, _ioCheck: function(/*Deferred*/dfd){ //summary: inflight check function to see if IO finished. //Check for finished jsonp if(dfd.ioArgs.json){ return true; } //Check for finished "checkString" case. var checkString = dfd.ioArgs.args.checkString; if(checkString && eval("typeof(" + checkString + ") != 'undefined'")){ return true; } return false; }, _resHandle: function(/*Deferred*/dfd){ //summary: inflight function to handle a completed response. if(dojo.io.script._ioCheck(dfd)){ dfd.callback(dfd); }else{ //This path should never happen since the only way we can get //to _resHandle is if _ioCheck is true. dfd.errback(new Error("inconceivable dojo.io.script._resHandle error")); } }, _jsonpCallback: function(/*JSON Object*/json){ //summary: // generic handler for jsonp callback. A pointer to this function // is used for all jsonp callbacks. NOTE: the "this" in this // function will be the Deferred object that represents the script // request. this.ioArgs.json = json; } } }
