/** * DataRequestor Class v: 1.5b - Feb 13, 2006 * * Copyright 2005 - Mike West - http://mikewest.org/ * * This software is licensed under the CC-GNU LGPL * * This class wraps the XMLHttpRequest object with a friendly API * that makes complicated data requests trivial to impliment in * your application. * * USAGE: * ---- * BASIC * To instantiate the object, simply call it as a constructor: * * var req = new DataRequestor(); * * Once you have the object instantiated, your usage will depend * on your needs. * * RETURNING TEXT * If you want to grab data, and shove it wholesale into an element * on the page (which I do 90% of the time), then tell the DataRequestor * object where to stick the info by passing setObjToReplace an * element ID or object reference, and call getURL to complete the * process: * * req.setObjToReplace('objID'); * req.getURL(url); * * * RETURNING A DOM OBJECT * By default, the contents of the requested file will be passed in as * plaintext, which can be simpler to work with than a real DOM object. * If you'd like a DOM object to work with, then call getURL with * _RETURN_AS_DOM as the second argument: * * req.getURL(url, _RETURN_AS_DOM); * * To avoid irritating problems, make sure you're sending a Content-type header * of "text/xml" when you'd like your data processed as a DOM object. IE gets * confused otherwise. * * RETURNING A JSON OBJECT * If you've no idea what JSON is, visit http://www.json.org/ * * To get a JavaScript object back from DataRequestor, call getURL with * with _RETURN_AS_JSON as the second parameter. * * req.getURL(url, _RETURN_AS_JSON); * * This, of course, assumes that you've generated a JSON string correctly * at the URL you've requested. * ---- * ARGUMENTS * * To pass in GET or POST variables along with your request, use the * addArg method: * * req.addArg(argType, argName, argValue); * e.g. * req.addArg(_GET, "argument_number", "1"); * * addArg will automatically call escape() on the name and value to * ensure they are URL escaped correctly. * * ARGUMENTS FROM A FORM * * To pass in all the arguments from a form, use the `addArgsFromForm` * method. This will automatically call `addArg` on each of the form * elements using the `method` attribute of the form to set the request * method for the arguments. Each form element *must* have an ID for this * method to function correctly. * * req.addArgsFromForm(formID); * e.g. * req.addArgsFromForm("myFormName"); * ---- * EVENT HANDLERS * * ON LOAD * * To take action when the data loads successfully, set onload to a function that * takes two arguments: data, and obj. This will be called upon successful retrieval * of the requested information, and will be passed the data retrieves and the object * that will be replaced (or null if no replacement has been requested). * * req.onload = function (data, obj) { * alert("Callback handler called with the following data: \n" + data); * } * * The first parameter (`data`) will be one of three things: * - text: If getURL was called without a second argument, or _RETURN_AS_TEXT, * then `data` contains the raw text returned by the page that you loaded. * * - DOM object: If getURL was called with _RETURN_AS_DOM as the second argument, then * `data` contains a DOM object, with blank whitespace nodes removed in order to * provide a consistant experience between browsers that support the DOM standard * and IE. * * - JavaScript object: If getURL was called with _RETURN_AS_JSON as the second argument, * then `data` contains a JavaScript object generated from the JSON text that was returned * by the page you loaded. * * ON REPLACE * * If you requested a replacement by setting an `objToReplace`, then this handler will * be called directly after the replacement occurs, and will be passed the same variables * as the `onload` method. * * req.onreplace = function (data, obj) { * alert("Callback handler called with the following data: \n" + data); * } * * ERROR HANDLING * * If the request fails, the XMLRequestor object defaults to simply throwing * an error. If that's not a great solution for you, then assign a function * to onfail that accepts a single variable: the XMLHttpRequest status * code. Do with it what you will: * * req.onfail = function (status) { * alert("The handler died with a status of " + status); * } * * PROGRESS * * In Mozilla, it's possible to dynamically retrieve the amount of data that * has been downloaded so far. If you'd like to take an action on that data * (e.g. set up some sort of progress bar) then set an onprogress handler that * accepts two arguments, currentLength and totalLength. Curiously enough, * these arguments will be populated with the current amount of data that's been * retrieved and the total size (or -1 if it can't be detected) * * req.onprogress = function (current, total) { * alert(current + " of " + total + " = " + ((total - current)/total) + "%"); * } * */ var _RETURN_AS_JSON = 2; var _RETURN_AS_TEXT = 1; var _RETURN_AS_DOM = 0; var _REPLACE_MULTI = 1; //hack added by Chris -- dont do _RETURN_AS behaviour .. instead replace multiple blocks of content - in ___ONE____ call. Not 2 or 600. ONE. var _POST = 0; var _GET = 1; var _CACHE = 0; var _NO_CACHE = 1; function DataRequestor() { var self = this; // workaround for scope errors: see http://www.crockford.com/javascript/private.html /** * Create XMLHttpRequest object: handles branching between * versions of IE and other browers. Inital version from: * http://jibbering.com/2002/4/httprequest.html (GREAT resource) * * later version adapted from: * http://jpspan.sourceforge.net/wiki/doku.php?id=javascript:xmlhttprequest:behaviour:httpheaders * * @return the XMLHttpRequest object */ this.getXMLHTTP = function() { var xmlHTTP = null; try { xmlHTTP = new XMLHttpRequest(); } catch (e) { try { xmlHTTP = new ActiveXObject("Msxml2.XMLHTTP") } catch(e) { var success = false; var MSXML_XMLHTTP_PROGIDS = new Array( 'Microsoft.XMLHTTP', 'MSXML2.XMLHTTP', 'MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0' ); for (var i=0;i < MSXML_XMLHTTP_PROGIDS.length && !success; i++) { try { xmlHTTP = new ActiveXObject(MSXML_XMLHTTP_PROGIDS[i]); success = true; } catch (e) { xmlHTTP = null; } } } } self._XML_REQ = xmlHTTP; return self._XML_REQ; } /** * Starts the request for a url. XMLHttpRequest will call * the default callback method when the request is complete * @param url the URL to request: absolute or relative will work * @param return optional arg: defaults to _RETURN_AS_TEXT. if set to _RETURN_AS_DOM, will return a DOM object instead of a string * @return true */ //CH adds nwe param prebuiltPostUrlString for posting a prebuilt string. this.getURL = function(url, prebuiltPostUrlString) { self.userModifiedData = ""; // clear user modified data; // DID THE USER WANT A DOM OBJECT, OR JUST THE TEXT OF THE REQUESTED DOCUMENT? switch (arguments[1]) { case _RETURN_AS_DOM: case _RETURN_AS_TEXT: case _RETURN_AS_JSON: self.returnType = arguments[1]; break; default: self.returnType = _RETURN_AS_TEXT; } // CLEAR OUT ANY CURRENTLY ACTIVE REQUESTS if ((typeof self._XML_REQ.abort) != "undefined" && self._XML_REQ.readyState!=0) { // Opera can't abort(). self._XML_REQ.abort(); } // SET THE STATE CHANGE FUNCTION self._XML_REQ.onreadystatechange = self.callback; // GENERATE THE POST AND GET STRINGS var requestType = "GET"; var getUrlString = (url.indexOf("?") != -1)?"&":"?"; for (var i in self.argArray[_GET]) { getUrlString += i + "=" + self.argArray[_GET][i] + "&"; } var postUrlString = ""; //this prebuiltPostUrlString is a CH hack. if (prebuiltPostUrlString) { postUrlString = prebuiltPostUrlString; } for (i in self.argArray[_POST]) { postUrlString += i + "=" + self.argArray[_POST][i] + "&"; } if (postUrlString != "") { requestType = "POST"; // Only POST if we have post variables } // MAKE THE REQUEST self._XML_REQ.open(requestType, url + getUrlString, true); if ((typeof self._XML_REQ.setRequestHeader) != "undefined") { // Opera can't setRequestHeader() if (self.returnType == _RETURN_AS_DOM && typeof self._XML_REQ.overrideMimeType == "function") { self._XML_REQ.overrideMimeType('text/xml'); // Make sure we get XML if we're trying to process as DOM } self._XML_REQ.setRequestHeader('Content-Type','application/x-www-form-urlencoded'); } self._XML_REQ.send(postUrlString); return true; } /** * A CH addition * post form fields to the url by building the url from fields in the specified div, and then passing the url and postString to this.getURL * and this was added because we cannot have nested forms, and yet we want new form fields to magically appear INSIDE the form, and then submit ONLY those fields and have them go away. or something. * */ this.postFieldsToUrl = function(url, fieldsDivId) { var postUrlString = this.buildPostUrlString(fieldsDivId); this.getURL(url, postUrlString); } /** * The default callback method: this is called when the XMLHttpRequest object * changes state. * - If the readystate == 4 (done) and the status == 200 (OK), then * the request was successful, and we take some action: * - If the user has set an object to replace, we check to see if we recieved plaintext (default) * or if the text should be run through eval first. * * - If we recieved plaintext, we simply replace the relevant object on the page with the * text we received. * * - If we recieved text to evaluate, we call eval() on it, and then replace the object * wholesale with _DOM_OBJ (which resulted from the eval) using replaceChild() on * self.objToReplace's parentNode. * * - If the user has set an onLoad method, we call it. If they requested a DOM object, we * pass it responseXML with blank text nodes stripped (to normalize between mozilla and * IE. If not, we pass them back plaintext. * * - Else if the readystate is 3 (loading), and the user has set an onProgress handler, and * we're not in IE (which has a broken readyState 3: http://jpspan.sourceforge.net/wiki/doku.php?id=javascript:xmlhttprequest:behaviour) * then call it with two arguments: the current number of bytes we've downloaded, and the total size (or -1 if we can't tell). * * - Else if the readystate is 4, and the status isn't 200 (not OK), then we failed * somehow, so we either call the callbackFailure method, or throw an error. */ this.callback = function() { if (self.onLoad) { self.onload = self.onLoad; } if (self.onReplace) { self.onreplace = self.onReplace; } if (self.onProgress) { self.onprogress = self.onProgress; } if (self.onFail) { self.onfail = self.onFail; } if ( (self._XML_REQ.readyState == 4 && self._XML_REQ.status == 200) || (self._XML_REQ.readyState == 4 && self._XML_REQ.status == 0) // Uncomment for local (non-hosted files) /* || (self._XML_REQ.readyState == 4 && (typeof self._XML_REQ.status) == 'undefined') /* Safari 2.0/1.3 has a strange bug related to not returning the correct status */ ) { //CH addition for replace multi if (self.replaceAs == _REPLACE_MULTI) { //new code of Chris to get multiple html blocks from inside an xml response and jam their contents into corresponding divs on the page. //while the following is interesting, it is no longer required. (and it didnt work unless the html was perfectly formatted XHTML which it was not and never would have been) //ok we want to just get the html out of the element. in Moz we have to use the XMLSerializer cuz there's no xml prop. // var html; // try { // var serializer = new XMLSerializer(); // html = serializer.serializeToString(node); // } catch (e) { // html = node.xml; // } // // this following is interesting as well and can help to debug // //debuggery and learning stuff. // alert ( // "there was a node.\n" + // "\n type: " + node.className + // "\n nodeName:" + node.nodeName + // "\n nodeValue:" + node.nodeValue + // //"\n # attribs: " + node.attributes.length + // //"\n content_id attrib: " + node.getAttribute('content_id') + // "\n noteType:" + node.nodeType + // "\n innerHTML:" + node.innerHTML + // "\n data:" + node.data + // "\n html:" + html // ); //alert('I seem to have been called the way you want.'); var xmlDoc; var blocks = new Array(); //so if we didnt get a xmlDoc then we'll loop over blocks 0 times and return pretty quickly. try { xmlDoc = self._XML_REQ.responseXML.documentElement; blocks = xmlDoc.getElementsByTagName('block'); } catch (uselessResponseException) { // commented out for now, so if there is an error, an ugly alert box doesn't pop-up, just the ticker won't be shown //alert("Exception raised while trying to obtain documentElement from responseXML -- probably a useless response was returned (below as responseText): \n\n" + self._XML_REQ.responseText); } //alert('there were ' + blocks.length + ' blocks returned'); for (var i = 0; i < blocks.length; i++) { var block = blocks[i]; var blockNodes = blocks[i].childNodes; var html = ''; for (var j = 0; j < blockNodes.length; j++) { //find CDATA nodes, type == 4. Add their content to the html we want to stick into the target div. //WHY THE *@^$ was it so hard to find out how to do this right? Guess I dont know as much as I think!!! if (blockNodes[j].nodeType == 4) { html = blockNodes[j].data; break; //stop after first CDATA node extracted. } } //each block will tell us what to do with it. we might be updating content, or hiding the object altogether. var target_name; if (block.getAttribute('target_id')) { target_id = block.getAttribute('target_id'); //easy. } else if (block.getAttribute('target_name')) { //ok we have to get the id from the list. target_name = block.getAttribute('target_name'); target_id = self.targets[target_name]; //alert('from a target named' + block.getAttribute('target_name') + ' we figured out an id of ' + target_id); } if (target_id) { var updateObj = document.getElementById(target_id); //so what are we doing to this object? if (updateObj) { //hiding the object if (block.getAttribute('action') == "hide") { //Note, we just assume we're hiding a table row at this point. If we ever want to do otherwise we'll need to add code here to detect what it is we're trying to hide and then get the proper css for that. updateObj.style.display = "none"; updateObj.style.visibility = "hidden"; } //setting content for the object if (block.getAttribute('action') == "content") { //set as value attribute if dest obj is actually an input. if (updateObj.nodeName == "TEXTAREA" || updateObj.nodeName == "INPUT") { updateObj.value = html; } else { //alert('will be putting this html into object id ' + updateObjId + "\n\n" + html); try { updateObj.innerHTML = html; } catch (setInnerHTMLException) { // commented out for now, so if there is an error, an ugly alert box doesn't pop-up, just the ticker won't be shown //alert('Exception raised while trying to put the following html into the innerHTML of object id ' + updateObjId + ". Known causes of errors are:\n - attempting to create nested forms. \n\nHTML follows:\n\n" + html); } } } //what about callbacks? -- only will work if a target_name is specified and the callbacks array has it listed. if (self.callbacks[target_name]) { self.callbacks[target_name](); //call it. did I do that right? } } } } //end loop over block elements } else { //END OF CH addition for replace multi var obj = self.getObjToReplace(); if (self.onload) { switch (self.returnType) { case _RETURN_AS_TEXT: // We want text back, so send responseText self.onload(self._XML_REQ.responseText, obj); break; case _RETURN_AS_DOM: // We want a DOM object back, so send a normalized responseXML self.onload(self.normalizeWhitespace(self._XML_REQ.responseXML), obj); break; case _RETURN_AS_JSON: // We want a javascript object back, so give it: self.onload(eval('(' + self._XML_REQ.responseText + ')'), obj); break; } } if (obj) { // We're going to replace obj's content with the text returned from the XML_REQ. // The old content will be stored in self.objOldContent, the new content in // self.objNewContent // We treat TEXTAREA and INPUT nodes differently (because IE crashes if you // try to adjust a TEXTAREA's innerHTML). if (obj.nodeName == "TEXTAREA" || obj.nodeName == "INPUT") { self.objOldContent = obj.value; obj.value = (self.userModifiedData)?self.userModifiedData:self._XML_REQ.responseText; self.objNewContent = obj.value; } else { self.objOldContent = obj.innerHTML; obj.innerHTML = (self.userModifiedData)?self.userModifiedData:self._XML_REQ.responseText; self.objNewContent = obj.innerHTML; } if (self.onreplace) { self.onreplace(obj, self.objOldContent, self.objNewContent); } } } } else if (self._XML_REQ.readyState == 3) { if (self.onprogress && !document.all) { // This would throw an error in IE. var contentLength = 0; // Depends on server. If content-length isn't set, catch the error try { contentLength = self._XML_REQ.getResponseHeader("Content-Length"); } catch (e) { contentLength = -1; } self.onprogress(self._XML_REQ.responseText.length, contentLength); } } else if (self._XML_REQ.readyState == 4) { if (self.onfail) { self.onfail(self._XML_REQ.status); } else { throw new Error("Data Request failed with an HTTP status of " + self._XML_REQ.status + "\nresponseText = " + self._XML_REQ.responseText); } } } /** * Normalizes whitespace between mozilla and IE * - removes blank text nodes (where "blank" is defined as "containing no non-space characters") * @param domObj the root of the DOM object to normalize */ this.normalizeWhitespace = function (domObj) { // with thanks to the kind folks in this thread: // http://www.codingforums.com/archive/index.php/t-7028 if (document.createTreeWalker) { var filter = { acceptNode: function(node) { if (/\S/.test(node.nodeValue)) { return NodeFilter.FILTER_SKIP; } return NodeFilter.FILTER_ACCEPT; } } var treeWalker = document.createTreeWalker(domObj, NodeFilter.SHOW_TEXT, filter, true); while (treeWalker.nextNode()) { treeWalker.currentNode.parentNode.removeChild(treeWalker.currentNode); treeWalker.currentNode = domObj; } return domObj; } else { return domObj; } } /** * A CH addition * build a POST variables string from the values of fields contained in the specified div id. * this is to help in submitting forms that have been dynamically loaded via XMLHttpRequest */ this.buildPostUrlString = function (fieldsDivId, debug) { var fieldsdiv = document.getElementById(fieldsDivId); var inputFields = fieldsdiv.getElementsByTagName('input'); var textAreas = fieldsdiv.getElementsByTagName('textarea'); var selectFields = fieldsdiv.getElementsByTagName('select'); var fsep = '&'; if (debug) { fsep += "\n"; } var postString = ''; if (debug) { postString += "\Inputs (text, hidden, password, checkbox, radio): \n"; } for (var i = 0; i < inputFields.length; i++) { var field = inputFields[i]; // alert ( // //"there was a radio button/checkbox.\n" + // "there was some kind of input field\n" + // "\n name:" + field.name + // "\n type:" + field.type + // "\n className: " + field.className + // "\n nadeName:" + field.nodeName + // "\n nodeValue:" + field.nodeValue + // "\n checked?:" + field.checked + // //"\n # attribs: " + field.attributes.length + // //"\n name attrib: " + field.getAttribute('name') + // "\n nodeType:" + field.nodeType + // "\n innerHTML:" + field.innerHTML + // "\n data:" + field.data // //"\n html:" + html // ); if (!field.type || !field.name) { continue; } var oT = field.type.toLowerCase(); if( oT == 'hidden' || oT == 'text' || oT == 'password') { postString += field.name + "=" + escape(field.value) + fsep; } else if ((oT == 'radio' || oT == 'checkbox') && field.checked) { postString += field.name + "=" + escape(field.value) + fsep; } } if (debug) { postString += "\nTextAreas: \n"; } for (var i = 0; i < textAreas.length; i++) { var field = textAreas[i]; if (!field.name || !field.type) { //select field with no field name or no type (not sure how the type thing would happen but it can), skipping'); continue; } postString += field.name + "=" + escape(field.value) + fsep; } if (debug) { postString += "\nSelect Fields: \n"; } for (var i = 0; i < selectFields.length; i++) { var field = selectFields[i]; if (!field.name || !field.type) { //select field with no field name or no type (not sure how the type thing would happen but it can), skipping'); continue; } var fldOpts = field.options; //alert ('field had ' + fldOpts.length + ' options'); for (var j = 0; fldOpts[j]; j++) { //so the condition each loop is just that the element exists. no element, stop the loop. simple, but I would never usually write it like that. So as you probably guessed, someone else did and then I had to understand what it meant and then I said hey thats neato I should use something like that. //alert ('inspecting a field option'); if (fldOpts[j].selected) { postString += field.name + "=" + escape(fldOpts[j].value) + fsep; } } } if (debug) { alert (postString) return 1; } else { return postString; } } this.commitData = function (newData) { self.userModifiedData = newData; } /** * Sets the object to replace. If passed a string, it sets objToReplaceID, which * is evaluated at runtime. Else, it sets objToReplace to the object reference * it was passed. * @param obj a reference to the object to replace, or the object's ID */ this.setObjToReplace = function(obj) { if (arguments[1] == _REPLACE_MULTI) { self.replaceAs = _REPLACE_MULTI; if (arguments[2]) { self.targets = arguments[2]; //this must be an Array } if (arguments[3]) { self.callbacks = arguments[3]; //this must be an Array of function refs. } } //with the multi item replace hack we may not get an object. if (obj) { if (typeof obj == "object") { self.objToReplace = obj; } else if (typeof obj == "string") { self.objToReplaceID = obj; } } } /** * Returns a reference to the object set by objToReplace */ this.getObjToReplace = function() { if (self.objToReplaceID != "") { self.objToReplace = document.getElementById(self.objToReplaceID); self.objToReplaceID = ""; } return self.objToReplace; } /** * Adds an argument to the GET or POST strings. * @param type _GET or _POST * @param name the argument's name * @param value the argument's value */ this.addArg = function(type, name, value) { self.argArray[type][name] = escape(value); } /** * Clears the argument lists */ this.clearArgs = function() { self.argArray[_POST] = new Array(); self.argArray[_GET] = new Array(); } /** * Adds all the variables from an HTML form to the GET or * POST strings, based on the `method` attribute` of the * form * @param formID the ID of the form to be added */ //This is MikeWest's code. I dont think it does anything like what I'll actually need .. I've put my own formfield value getting shit in here. this.addArgsFromForm = function(formID) { var theForm = document.getElementById(formID); // Get form method, default to GET var submitMethod = (theForm.getAttribute('method').toLowerCase() == 'post')?_POST:_GET; // Get all form elements and use `addArg` to add them to the GET/POST string for (var i=0; i < theForm.childNodes.length; i++) { theNode = theForm.childNodes[i]; switch(theNode.nodeName.toLowerCase()) { case "input": case "select": case "textarea": this.addArg(submitMethod, theNode.id, theNode.value); break; } } } /** * Resets everything to defaults */ this.clear = function() { self.returnType = _RETURN_AS_TEXT; self.argArray = new Array(); self.objToReplace = null; self.objToReplaceID = ""; self.replaceAs = null; self.targets = null; self.callbacks = null; self.onload = null; self.onfail = null; self.onprogress = null; self.cache = new Array(); this.clearArgs(); } // ENSURE THAT WE'VE GOT AN XMLHttpRequest OBJECT AVALIABLE if (!this.getXMLHTTP()) { throw new Error("Could not load XMLHttpRequest object"); } this.clear(); }