Cross-Domain Requests with jQuery - ajax

For a project I need to get the source code of web page of different other domains.
I have tried following code:
$('#container').load('http://google.com');
$.ajax({
url: 'http://news.bbc.co.uk',
type: 'GET',
success: function(res) {
var headline = $(res.responseText).find('a.tsh').text();
alert(headline);
}
});
Still I am not getting any results but just a blank alert box.

By default all browsers restrict cross-domain requests, you can get around this by using YQL as a proxy. See a guide here: http://ajaxian.com/archives/using-yql-as-a-proxy-for-cross-domain-ajax

For security reasons scripts aren't able to access content from other domains. Mozilla has a long article about HTTP access control, but the bottom line is that without the website themselves adding support for cross-domain requests, you're screwed.

This code is Working Perfectly with the help of JQuery and YQL
$(document).ready(function(){
var container = $('#target');
$('.ajaxtrigger').click(function(){
doAjax($(this).attr('href'));
return false;
});
function doAjax(url){
if(url.match('^http')){
$.getJSON("http://query.yahooapis.com/v1/public/yql?"+
"q=select%20*%20from%20html%20where%20url%3D%22"+
encodeURIComponent("http://www.yahoo.com")+
"%22&format=xml'&callback=?",
function(data){
if(data.results[0]){
var data = filterData(data.results[0]);
container.html(data);
} else {
var errormsg = '<p>Error: could not load the page.</p>';
container.html(errormsg);
}
}
);
} else {
$('#target').load(url);
}
}
function filterData(data){
data = data.replace(/<?\/body[^>]*>/g,'');
data = data.replace(/[\r|\n]+/g,'');
data = data.replace(/<--[\S\s]*?-->/g,'');
data = data.replace(/<noscript[^>]*>[\S\s]*?<\/noscript>/g,'');
data = data.replace(/<script[^>]*>[\S\s]*?<\/script>/g,'');
data = data.replace(/<script.*\/>/,'');
return data;
}
});

The solution for your case is JSON with padding or JSONP.
You will need an HTML element that specified for its src attribute a URL that returns JSON like this:
<script type="text/javascript" src="http://differentDomain.com/RetrieveUser?UserId=1234">
You can search online for a more in-depth explanation, but JSONP is definitely your solution for this.

Do the following steps.
1: Add datatype:jsonp to the script.
2: Add a "callback" parameter to the url
3: Create a javascript function with name same as "callback" param value.
4: The output can be received inside javascript function.

Found one more solution for this :
function getData(url){
if(url.match('^http')){
$.get(url,
function(data){
process(data);
}//end function(data)
);//end get
}
}
This is really a pretty easier way to handle cross-domain requests. As some of the sites like www.imdb.com rejects YQL requests.

Related

AJAX response returns current page

I was searching for a similar issue for a while now, but none of the solutions worked for me (and I couldn't find exactly the same issue).
First of all, the website I'm working on is running on Zend Framework. I suspect that it has something to do with the issue.
I want to make a pretty basic AJAX functionality, but for some reason my response always equals the html of the current page. I don't need any of Zend's functionality, the functions I need to implement could (and I'd prefer them to) work separately from the framework.
For testing purposes I made it as simple as I could and yet I fail to find the error. I have a page "test.php" which only has a link that triggers the ajax call. Here's how this call looks:
$('.quiz-link').click(function(e){
e.preventDefault();
$.ajax({
URL: "/quiz_api.php",
type: "POST",
cache: false,
data: {
'test': 'test'
},
success: function(resp){
console.log(resp);
},
error: function(resp){
console.log("Error: " + reps);
}
});
});
And this quiz_api.php is just:
<?php
echo "This is a test";
?>
When I click on the link I get the entire HTML of the current page. "This is a test" can't be found there. I'm also getting an error: "Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/."
I reckon it has to do with the JS files that are included into this HTML response, but I've also tried setting "async: true" and it didn't help.
I would like to avoid using Zend Framework functions for this task, because I'm not well familiar with it and even making a simple controller sounds rather painful. Instead I want to find out what's causing such behavior and see if it can be changed.
PS: I've also tried moving quiz_api.php to another domain, but it didn't change anything.
I know that it might be an older code but it works, simple and very adaptable. Here's what I came up with. Hope it works for you.
//Here is the html
Link Test
<div id="test_div"></div>
function test(){
// Create our XMLHttpRequest object
var hr = new XMLHttpRequest();
// This is the php file link
var url = "quiz_api.php";
// Attaches the variables to the url ie:var1=1&var2=2 etc...
var vars = '';
hr.open("POST", url, true);
//Set content type header information for sending url encoded variables in the request
hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
// Access the onreadystatechange event for the XMLHttpRequest object
hr.onreadystatechange =
function(){
if(hr.readyState == 4 && hr.status == 200){
var return_data = hr.responseText;
console.log(return_data);
document.getElementById('test_div').innerHTML = return_data;
}else{
document.getElementById('test_div').innerHTML = "XMLHttpRequest failed";
}
}
//Send the data to PHP now... and wait for response to update the login_error div
hr.send(vars); // Actually execute the request
}
you can change the whole page with a document.write instead of changing individual "div"s

304 not modified, Ajax is not working?

<script>
var xmlHttp =new XMLHttpRequest();
var url= "summary.txt";
xmlHttp.onreadystatechange = function() {
if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
var myArr = JSON.parse(xmlHttp.responseText);
myFunction(myArr);
}
xmlHttp.open("GET", url , true);
xmlHttp.send();
} function myFunction(arr)
var output="";
var i;
for(i=0;i<arr.length;i++){
output+='<p>'+arr[i].title+arr[i].image+arr[i].price+'</p>';
}
document.getElementById("proTab").innerHTML = output;
}
</script>
I stored all both the HTML and JSON in the htdocs folder, did xampp start and made sure Apache and mysql were running on the control panel. I then typed the link to the html using the "localhost/" to get to the html but the page was blank. Sorry for all the details.
Console says 304 Not modified. What should I do?
My guess is that you are using IE, which caches AJAX GET requests aggressively. I would suggest changing to using POST for the AJAX request.
Another alternative if you must use GET requests. You can add a unique querystring value to each GET request like this:
var url = 'summary.txt' + '?' + Math.random()*Math.random();
I used this for jQuery AJAX:
$.ajaxSetup({
// Disable caching of AJAX responses
cache: false
});
I think you can find how to use this for JS without jQuery. So the idea is to clear cache before sending the request, because server responds that nothing changed and sends 304 NOT MODIFIED instead of 200 OK. Namely, your summary.txt hasn't changed (not modified), so that's what server telling you.

Ajax send parameters through url

I'm new with ajax and thought i'd be a fun experiment to put into my project. I've created my own lightbox type feature to send a message on a website I'm creating. When the user clicks "Send Message", that's when the lightbox appears, and at the top I'm trying to get it to say "Send message to User", where User is the name of the user they're sending a message too. My lightbox html elements are actually on a seperate webpage, which is why I'm using ajax. this is what I have so far, and can't seem to figure out what the problem is:
user.php page
<div id = "pageMiddle"> // This div is where all the main content is.
<button onclick = "showMessageBox(UsersName)">Send Message</button>
</div>
Note: The username passes correctly into the javascript function, I have checked that much.
main.js page
function showMessageBox(user){
alert(user); // where i checked if username passes correctly
var ajaxObject = null;
if (window.XMLHttpRequest){
ajaxObject = new XMLHttpRequest();
}else if (window.ActiveXObject){
ajaxObject = new ActiveXObject("Microsoft.XMLHTTP");
}
if (ajaxObject != null){
ajaxObject.open("GET", "message_form.php", true);
ajaxObject.send("u="+user);
}else{
alert("You do not have a compatible browser");
}
ajaxObject.onreadystatechange = function(){
if (ajaxObject.readyState == 4 && ajaxObject.status == 200){
document.getElementById("ajaxResult").innerHTML = ajaxObject.responseText;
// use jquery to fade out the background and fade in the message box
$("#pageMiddle").fadeTo("slow", 0.2);
$("#messageFormFG").fadeIn("slow");
}
};
}
message_form.php page
<div id = "messageFormFG">
<div class = "messageFormTitle">Sending message to <?php echo $_GET['u']; ?></div>
</div>
Note: When accessing this page directly through the URL, giving it a parameter of u and a value, it displays correctly
Use jQuery.ajax();
http://api.jquery.com/jQuery.ajax/
$.ajax({
type: "GET",
url: "message_form.php",
data: { name: "John", location: "Boston" }
}).done(function( msg ) {
alert( "Data Saved: " + msg );
});
freakish way to do it (old school) :)
anyway i think the problem may be that you are loading an entire html page to a div! meaning tags and stuff, a good way to understand what's wrong would be to use a debugger and see what comes in ajaxObject.responseText.
Hope this helps.
Btw convert to jQuery ajax!! saves you loads of time =)
I believe that you need to add a request header prior to sending your data. So you'd have this:
ajaxObject.open("GET", "message_form.php", true);
ajaxObject.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
ajaxObject.send("u="+encodeURIComponent(user));
Instead of what you have.
However, it may be a good idea to allow a library to do this for you. It looks like you already have jQuery loaded, so why not let it handle your AJAX requests instead?
I figured it out after watching some ajax tutorials from bucky :) aka thenewboston. If I'm using the GET method, i just had to add the parameter to the end of the url in the .open function, instead of passing it through the send function (like you would a post method).
if you want to send number of field values using ajax.you can use serilalize function.
Example:
jQuery.ajax({
url: 'filenamehere.php',
type: 'post',
data: $("#formidhere").serialize(),
success: function(data){
..//
}
});

dynamicly fill table using zpt and ajax as update

I'm creating a webproject in pyramid where I'd like to update a table every few secondes. I already decided to use ajax, but I'm stuck on something.
On the client side I'm using the following code:
function update()
{
var variable = 'variable ';
$.ajax({
type: "POST",
url: "/diagnose_voorstel_get_data/${DosierID}",
dataType: "text",
data: variable ,
success: function (msg) {
alert(JSON.stringify(msg));
},
error: function(){
alert(msg + 'error');
}
});
}
Pyramid side:
#view_config(route_name='diagnose_voorstel_get_data', xhr=True, renderer='string')
def diagnose_voorstel_get_data(request):
dosierid = request.matchdict['dosierid']
dosieridsplit = dosierid.split
Diagnoses = DBSession.query(Diagnose).filter(and_(Diagnose.code_arg == str(dosieridsplit[0]), Diagnose.year_registr == str(dosieridsplit[1]), Diagnose.period_registr == str(dosieridsplit[2]), Diagnose.staynum == str(dosieridsplit[3]), Diagnose.order_spec == str(dosieridsplit[4])))
return {'Diagnoses ' : Diagnoses }
Now I want to put this data inside a table with zpt using the tal:repeat statement.
I know how to use put this data in the table when the page loads, but I don't know how to combine this with ajax.
Can anny1 help me with this problem ? thanks in adance.
You can do just about anything with AJAX, what do you mean "there's no possibility"? Things become much cleaner once you clearly see what runs where and in what order - as Martijn Pieters points out, there's no ZPT in the browser and there's no AJAX on the server, so the title of the question does not make much sense.
Some of the options are:
clent sends an AJAX request, server does its server-side stuff, in the AJAX call success handler the client reloads the whole page using something like window.location.search='ts=' + some_timestamp_to_invalidate_cache. The whole page will reload with the new data - although it works almost exactly like a normal form submit, not much sense using AJAX like this at all.
client sends an AJAX request, server returns an HTML fragment rendered with ZPT which client then appends to some element on your page in the AJAX success handler:
function update()
{
var variable = 'variable ';
$.post("/diagnose_voorstel_get_data/${DosierID}")
.done(function (data) {'
$('#mytable tbody').append(data);
});
}
client sends an AJAX request, server returns a JSON object which you then render on the client using one of the client-side templating engines. This probably only make sense if you render your whole application on the client and the server provides all data as JSON.

Send Multiple data with ajax

I want to use ajax for add data in database and i found following code in net and it is working fine.
<script language='javascript'>
reqObj=null;
function saveCust(){
document.getElementById('res').innerHTML='processing';
if(window.XMLHttpRequest){
reqObj=new XMLHttpRequest();
}else {
reqObj=new ActiveXObject('Microsoft.XMLHTTP');
}
reqObj.onreadystatechange=processSave;
reqObj.open('POST','./custSave?reqObj.open('POST','./cName?id='+document.getElementById('CustCode').value,true);,true);
reqObj.send(null);
}
function processSave(){
if(reqObj.readyState==4){
document.getElementById('res').innerHTML=reqObj.responseText;
}
}
</script>
Above code sends only one String but, i have 5 Strings in my form.
Please anybody alter the code for sending multiple data.
The problem is that you're sending a single parameter in the reqObj.open function:
reqObj.open('POST','./custSave?reqObj.open('POST','./cName?id='+document.getElementById('CustCode').value,true);,true);
Note that the only parameter you send is id.
You can add more parameters in the flavor of QueryString:
id=something&otherParameter=else //and more parameters
IMO the easiest way to handle an ajax request would be using jQuery, as shown and heavily explained by BalusC in How to use Servlets and Ajax?.
Based on the samples there and jQuery Ajax POST example with PHP, you can come with the following code:
Assuming the 5 Strings are in the form
function saveCust(){
$('#res').html('processing');
var $form = $(this);
var serializedData = $form.serialize();
$.post('./custSave', serializedData, function(responseText) {
$('#res').html(responseText);
});
}
Assuming there's data outside the form
function saveCust(){
$('#res').html('processing');
var $form = $(this);
var serializedData = $form.serialize() + "&id=" + $('#CustCode').val();
$.post('./custSave', serializedData, function(responseText) {
$('#res').html(responseText);
});
}
And you can even enhance this using more jQuery functions, but that's outside the scope of this answer.

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