I have a function that loads a JSON file and gives it to a variable called articles. When i log articles inside of the function, it shows my json file, but when i log it outside of my function it doesn't show anything at all
I have tried to use let and var before articles inside of the function but that doesn't seem to work
var articles = ""
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function(){
if(xmlhttp.status == 200 && xmlhttp.readyState == 4){
articles = xmlhttp.responseText;
console.log(articles);
}
};
console.log(articles);
console.log(xmlhttp);
xmlhttp.open("GET","articles.json",true);
xmlhttp.send();
I want to be able to call my json file outside of my function by using articles, so that i don't have ot type xml.responseText each time.
In short, JavaScript does not synchronously wait for I/O operations to finish (network call in this case).
What this means is that when you log articles "outside of the function", the articles variable has not yet been set (the http request has not been completed).
Why are you hoping to have access to articles globally?
You could optionally pass your articles into a processing method after the http request has responded like so:
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function(){
if(xmlhttp.status == 200 && xmlhttp.readyState == 4){
var articles = xmlhttp.responseText;
processArticles(articles)
}
};
xmlhttp.open("GET","articles.json",true);
xmlhttp.send();
function processArticles(articles) {
// Do something with articles here
}
I am working with JIVE JSON RESTFul API and on their API they have a security
(I am referring to the throw 'allowIllegalResourceCall is false.'; )
throw 'allowIllegalResourceCall is false.';
{
"id" : "52104",
}
I am using this code to try to PARSE IT:
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var myObj = JSON.parse(this.responseText);
document.getElementById("topdisplay").innerHTML = myObj.id;
}
};
xmlhttp.open("GET", "http://mysite/API/",true);
xmlhttp.send();
And I am getting an error because of that starting line.
I looked everywhere to try finding a solution to skip that to the JSON PARSE would work but I can't seem to find a way that works to do it.
Also I know that the parsing code works because when I remove the first line it works perfectly.
Any help?
JIVE REST API introduced this to help prevent against JSON Hijacking back when web browsers were susceptible.
You'll need to first find {, and do a substring from that position to the end of the string.
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var response = this.responseText
var myObj = JSON.parse(this.responseText.substring(this.response.indexOf('{')));
document.getElementById("topdisplay").innerHTML = myObj.id;
}
};
xmlhttp.open("GET", "http://mysite/API/",true);
xmlhttp.send();
NOTE:
using RegEx, you'll need to find the first line with throw and ending in a semi-colon, if found replace with an empty string.
JSON.parse(response.replace(/throw.*;/, "").trim());
I'm making and app and I need do get the number of verses of a chapter of the bible.
I'm getting the info from http://www.kingjamesbibleonline.org/
In order to do that I am making an XMLHttpRequest to send to the server from the function getVerses() from the site.
The problem that I am facing is that I'm not getting a .responseText from the XMLHttpRequest. When I use firebug and call that function, in the Network tab > Response tab I get nothing but on Network tab > Preview I get the answer.
Where is this answer coming from and what is the variable that has this value?
My node code is as follows:
let XMLHttpRequest2 = require("xmlhttprequest").XMLHttpRequest;
function getVerses() {
let xmlhttp = new XMLHttpRequest2(); //: new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == xmlhttp.DONE ) {
if(xmlhttp.status == 200){
console.log(xmlhttp.responseText);
}
else if(xmlhttp.status == 400) { }
else { }
}
}
xmlhttp.open("POST", "http://www.kingjamesbibleonline.org/ajax.php", true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xmlhttp.send('callFunc=getMaxVerseForChapter&book='+'"Genesis"'+'&chapter='+'"2"');
}
getVerses();
Apparently the server is very strict and it expects the header to be called Content-Type and not Content-type. Some kind of poorly written stuff obviously (in PHP). Also get rid of the double quotes around the values you are sending.
Here you go:
let XMLHttpRequest2 = require("xmlhttprequest").XMLHttpRequest;
function getVerses() {
let xmlhttp = new XMLHttpRequest2(); //: new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == xmlhttp.DONE ) {
if(xmlhttp.status == 200){
console.log(xmlhttp.responseText);
}
else if(xmlhttp.status == 400) { }
else { }
}
}
xmlhttp.open("POST", "http://www.kingjamesbibleonline.org/ajax.php", true);
xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlhttp.send('callFunc=getMaxVerseForChapter&book=' + 'Genesis' + '&chapter=' + '2');
}
getVerses();
and since you are hardcoding the values, you don't really need string concatenation:
xmlhttp.send('callFunc=getMaxVerseForChapter&book=Genesis&chapter=2);
First of all, any suggestions on rewriting my title?
Issue:
I have an AJAX updatable div, when my error checking alert calls are in, everything works perfect. But when I remove a specific one, the DIV never gets updated. I know it sounds confusing, but code is as follows, and then I will explain further.
AJAX SCRIPT
var xmlhttp
/*#cc_on #*/
/*#if (#_jscript_version >= 5)
try {
xmlhttp=new ActiveXObject("Msxml2.XMLHTTP")
} catch (e) {
try {
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")
} catch (E) {
xmlhttp=false
}
}
#else
xmlhttp=false
#end #*/
if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
try {
xmlhttp = new XMLHttpRequest();
} catch (e) {
xmlhttp=false
}
}
function myXMLHttpRequest() {
var xmlhttplocal;
try {
xmlhttplocal= new ActiveXObject("Msxml2.XMLHTTP")
} catch (e) {
try {
xmlhttplocal= new ActiveXObject("Microsoft.XMLHTTP")
} catch (E) {
xmlhttplocal=false;
}
}
if (!xmlhttplocal && typeof XMLHttpRequest!='undefined') {
try {
var xmlhttplocal = new XMLHttpRequest();
} catch (e) {
var xmlhttplocal=false;
alert('couldn\'t create xmlhttp object');
}
}
return(xmlhttplocal);
}
function sndReq(page,key,includesDir,changeDiv,parameterString) {
var divToChange = document.getElementById(changeDiv); // the Div that the data will be put into
// Place loading image in container DIV
divToChange.innerHTML = '<div class="loading">Loading</div>';
if (includesDir == 1){
//Find Current Working Directory. Use to find path to call other files from
var myloc = window.location.href;
var locarray = myloc.split("/");
delete locarray[(locarray.length-1)];
var arraytext = locarray.join("/");
xmlhttp.open("POST","AJAXCaller.php",true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xmlhttp.send(parameterString);
} else {
}
xmlhttp.onreadystatechange = handleResponse(changeDiv);
xmlhttp.send(null);
}
function handleResponse(changeDiv) {
/* ======== If I remove the following line script halts ================*/
/* ======== If line stays here, script executes perfectly ==============*/
alert('to changetext 1\n'+xmlhttp.responseText);
/* =========End of line removal issue =================================*/
if(xmlhttp.readyState == 4){
if (xmlhttp.status == 200){
var response = xmlhttp.responseText;
var update = new Array();
if(response.indexOf('|') != -1) {
update = response.split('|');
changeText(update[0], update[1]);
} else {
changeText(changeDiv, response);
}
} //End IF xmlhttp.status == 200
}
}
function changeText( div2show, text ) {
// Detect Browser
var IE = (document.all) ? 1 : 0;
var DOM = 0;
if (parseInt(navigator.appVersion) >=5) {DOM=1};
// Grab the content from the requested "div" and show it in the "container"
if (DOM) {
var viewer = document.getElementById(div2show);
viewer.innerHTML = text;
} else if(IE) {
document.all[div2show].innerHTML = text;
}
}
When I check my Firefox error console, this error ONLY appears when I remove that alert as defined in the code:
Timestamp: 5/30/2012 5:07:55 PM
Error: b.data is undefined
Source File: http://cdn.sstatic.net/js/wmd.js?v=cfd2b283af83
Line: 92
I am an advanced PHP/mySQL developer, but have been trying hard to grasp AJAX/JavaScript. Doing tutorials like mad. So please be descriptive in comments/answers so I can use them as a reference for learning...
Why would displaying an alert box alter code execution (for the better!) in any way?
NEW ERRORS - Google Chrome and Firefox Console (sigh...)
Uncaught Error: INVALID_STATE_ERR: DOM Exception 11
sndReqAJAX.js:89
element.onclick
Line 89 is the following (verified by Google Chrome Console)
xmlhttp.send(null);
Everything I find on the web refers to extremely complex issue regarding DOM objects not existing... This wouldn't apply here, would it?
First, the problem. This is the line:
xmlhttp.onreadystatechange = handleResponse(changeDiv);
The reason this is wrong is that xmlhttp.onreadystatechange should be a function - you need to assign a function to the property, what you are doing is calling the function and assigning the return value to the property. This is not in itself a problem, as long as your function returns a function. Which it doesn't.
If you're used to working with PHP (especially if your used to working with PHP <5.3) you may not be used to this concept. Javascript has support for closures in a way that anyone who doesn't use them much will find confusing.
What the line needs to look like is this:
xmlhttp.onreadystatechange = handleResponse;
By appending (changeDiv) you are calling the function, whereas what you need to do is simply pass it, like you would any other value.
Now, where it gets complicated is that you want to pass an argument that is local to the scope of the calling function. There are a number of ways to handle this, but a cursory look at your code tells me that handleResponse() is not used anywhere else, so it would be better to define this as a closure and not litter the global scope with a named event handler. This also overcomes the variable scoping problem:
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) {
var response = xmlhttp.responseText;
var update = []; // "new Array()" is baaaad
if (response.indexOf('|') != -1) {
update = response.split('|');
changeText(update[0], update[1]);
} else {
changeText(changeDiv, response);
}
} //End IF xmlhttp.status == 200
}
};
Replace the aforementioned offending line with that block of code, and remove the handleResponse() function definition, and that should solve the immediate problem. Now, as to why the alert() "fixes" your original code - this is a little hard to explain, but I shall have a go... give me a minute to inspect the code properly
Attempt at a full and comprehensible explanation abandoned. If anyone wants one, post a comment and I'll have another go at it when I've had some sleep...
I've been having some weird issues when it comes to make an AJAX request and handling the response.
I am making an ajax call for an xml file. however when i get the response the xhr.responseText property works fine in firefox but not in IE.
Another thing is that I am trying to access the xhr.responseXML as XMLDocument, but it tells me in firefox it tells me that xhr.responseXML is undefined in ie it doesnt even show me the undefined error or displays the output.
This is the code I am using to make the request:
var ajaxReq = function(url, callback) {
//initialize the xhr object and settings
var xhr = window.ActiveXObject ?
new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest(),
//set the successful connection function
httpSuccess = function(xhr) {
try {
// IE error sometimes returns 1223 when it should be 204
// so treat it as success, see XMLHTTPRequest #1450
// this code is taken from the jQuery library with some modification.
return !xhr.status && xhr.status == 0 ||
(xhr.status >= 200 && xhr.status < 300) ||
xhr.status == 304 || xhr.status == 1223;
} catch (e) { }
return false;
};
//making sure the request is created
if (!xhr) {
return 404; // Not Found
}
//setting the function that is going to be called after the request is made
xhr.onreadystatechange = function() {
if (!httpSuccess(xhr)) {
return 503; //Service Unavailable
}
if (xhr.responseXML != null && xhr.responseText != null &&
xhr.responseXML != undefined && xhr.responseText != undefined) {
callback(xhr);
}
};
//open request call
xhr.open('GET', url, true);
//setup the headers
try {
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.setRequestHeader("Accept", "text/xml, application/xml, text/plain");
} catch ( ex ) {
window.alert('error' + ex.toString());
}
//send the request
try {
xhr.send('');
} catch (e) {
return 400; //bad request
}
return xhr;
};
and this is how i am calling the function to test for results:
window.onload = function() {
ajaxReq('ConferenceRoomSchedules.xml', function(xhr) {
//in firefox this line works fine,
//but in ie it doesnt not even showing an error
window.document.getElementById('schedule').innerHTML = xhr.responseText;
//firefox says ''xhr.responseXML is undefined'.
//and ie doesn't even show error or even alerts it.
window.alert(xhr.reponseXML.documentElement.nodeName);
});
}
This is also my first attempt to work with AJAX so there might be something that I am not looking at right.
I've been searching crazy for any indications of why or how to fix it, but no luck there.
any ideas would be great.
EDIT:
I know this would be better with a framework, but the boss doesn't want to add a framework for just an ajax functionality ('just' is not a fair word for ajax :P). So I am doing it with pure javascript.
The XML file is well-formed, I see it well in the web browser, but for completion this is the testing file I am using:
<?xml version="1.0" encoding="utf-8"?>
<rooms>
<room id="Blue_Room">
<administrator>somebody#department</administrator>
<schedule>
<event>
<requester>
<name>Johnny Bravo</name>
<email>jbravo#department</email>
</requester>
<date>2009/09/03</date>
<start_time>11:00:00 GMT-0600</start_time>
<end_time>12:00:00 GMT-0600</end_time>
</event>
</schedule>
</room>
<room id="Red_Room">
<administrator>somebody#department</administrator>
<schedule>
</schedule>
</room>
<room id="Yellow_Room">
<administrator>somebody#department</administrator>
<schedule>
</schedule>
</room>
</rooms>
EDIT 2:
Well the good news is that I convinced my boss to use jQuery, the bad news is that AJAX still perplexes me. I'll read more about it just for curiousity. Thanks for the tips and I gave the answer credit to Heat Miser because he was the closest working tip.
I was having the same problem a few years ago, then I gave up on responseXML and began always using responseText. This parsing function has always worked for me:
function parseXml(xmlText){
try{
var text = xmlText;
//text = replaceAll(text,"<","<");
//text = replaceAll(text,">",">");
//text = replaceAll(text,""","\"");
//alert(text);
//var myWin = window.open('','win','resize=yes,scrollbars=yes');
//myWin.document.getElementsByTagName('body')[0].innerHTML = text;
if (typeof DOMParser != "undefined") {
// Mozilla, Firefox, and related browsers
var parser=new DOMParser();
var doc=parser.parseFromString(text,"text/xml");
//alert(text);
return doc;
}else if (typeof ActiveXObject != "undefined") {
// Internet Explorer.
var doc = new ActiveXObject("Microsoft.XMLDOM"); // Create an empty document
doc.loadXML(text); // Parse text into it
return doc; // Return it
}else{
// As a last resort, try loading the document from a data: URL
// This is supposed to work in Safari. Thanks to Manos Batsis and
// his Sarissa library (sarissa.sourceforge.net) for this technique.
var url = "data:text/xml;charset=utf-8," + encodeURIComponent(text);
var request = new XMLHttpRequest();
request.open("GET", url, false);
request.send(null);
return request.responseXML;
}
}catch(err){
alert("There was a problem parsing the xml:\n" + err.message);
}
}
With this XMLHttpRequest Object:
// The XMLHttpRequest class object
debug = false;
function Request (url,oFunction,type) {
this.funct = "";
// this.req = "";
this.url = url;
this.oFunction = oFunction;
this.type = type;
this.doXmlhttp = doXmlhttp;
this.loadXMLDoc = loadXMLDoc;
}
function doXmlhttp() {
//var funct = "";
if (this.type == 'text') {
this.funct = this.oFunction + '(req.responseText)';
} else {
this.funct = this.oFunction + '(req.responseXML)';
}
this.loadXMLDoc();
return false;
}
function loadXMLDoc() {
//alert(url);
var functionA = this.funct;
var req;
req = false;
function processReqChange() {
// alert('reqChange is being called');
// only if req shows "loaded"
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
// ...processing statements go here...
eval(functionA);
if(debug){
var debugWin = window.open('','aWindow','width=600,height=600,scrollbars=yes');
debugWin.document.body.innerHTML = req.responseText;
}
} else {
alert("There was a problem retrieving the data:\n" +
req.statusText + '\nstatus: ' + req.status);
if(debug){
var debugWin = window.open('','aWindow','width=600,height=600,scrollbars=yes');
debugWin.document.body.innerHTML = req.responseText;
}
}
}
}
// branch for native XMLHttpRequest object
if(window.XMLHttpRequest) {
try {
req = new XMLHttpRequest();
} catch(e) {
req = false;
}
// branch for IE/Windows ActiveX version
} else if(window.ActiveXObject) {
try {
req = new ActiveXObject("Msxml2.XMLHTTP");
} catch(e) {
try {
req = new ActiveXObject("Microsoft.XMLHTTP");
} catch(e) {
req = false;
}
}
}
if(req) {
req.onreadystatechange = processReqChange;
if(this.url.length > 2000){
var urlSpl = this.url.split('?');
req.open("POST",urlSpl[0],true);
req.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
req.send(urlSpl[1]);
} else {
req.open("GET", this.url, true);
req.send("");
}
}
}
function browserSniffer(){
if(navigator.userAgent.toLowerCase().indexOf("msie") != -1){
if(navigator.userAgent.toLowerCase().indexOf("6")){
return 8;
}else{
return 1;
}
}
if(navigator.userAgent.toLowerCase().indexOf("firefox") != -1){
return 2;
}
if(navigator.userAgent.toLowerCase().indexOf("opera") != -1){
return 3;
}
if(navigator.userAgent.toLowerCase().indexOf("safari") != -1){
return 4;
}
return 5;
}
Granted, this is very old code, but it is still working for me on a site I built a few years ago. I agree with everyone else though I typically use a framework nowadays so I don't have to use this code or anything like it anymore.
You can ignore some of the particulars with the split, etc... in the Request onreadystate function. It was supposed to convert the request to a post if it was longer than a certain length, but I just decided it was always better to do a post.
This problem occurs mostly when content type is mis-detected by the browser or it's not sent correctly.
Its easier to just override it:
var request = new XMLHttpRequest();
request.open("GET", url, false);
request.overrideMimeType("text/xml");
request.send(null);
return request.responseXML;
Not sure why... This problem occurs only with Safari and Chrome (WebKit browsers, the server sends the headers correctly).
Are you calling the URL relative to the current document? Since IE would be using the ActiveXObject, it might need an absolute path, for example:
http://some.url/ConferenceRoomSchedules.xml
As for the XML, are you sure it's well-formed? Does it load in an XML editor, for instance?
What I can suggest you is to take a look at frameworks that hide and manage these cross-browser issues for you (in a reliable way). A good point here is jQuery. Doing these things yourself can become quite difficult and complex.
This may be what you need.
//Edit:
This is how the w3school shows it:
function ajaxFunction()
{
var xmlhttp;
if (window.XMLHttpRequest)
{
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else if (window.ActiveXObject)
{
// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
else
{
alert("Your browser does not support XMLHTTP!");
}
}
To avoid your cross browser problems (and save yourself coding a lot of items that a strong community has already developed, tested, and reviewed), you should select a javascript library. JQuery and Dojo are great choices.
I believe that your web server need to serve correct response headers with 'ConferenceRoomSchedules.xml' e.g. Content-Type: text/xml or any other xml type.
The answer provided by Aron in https://stackoverflow.com/a/2081466/657416 is from my point of view the simplest (and the best) one. Here is my working code:
ajax = ajaxRequest();
ajax.overrideMimeType("text/xml");
ajax.open("GET", myurl;