Handle ajax response with node.js - ajax

I am trying to scrape information from a specified website. This site uses authentication first, thus a i use zombie.js:
var Browser = require("zombie");
var browser = new Browser();
browser.visit("https://*****login.aspx", function(){
browser.fill('#user', '*****');
browser.fill('#pwd', '*****');
var button = browser.querySelector('#btnSubmit');
browser.fire('click', button, function(){
//scraping main.aspx
});
});
It's working, i can scrape the main.aspx: there is a <table>, containig information about new messages(from, date, subject,), the problems comes here: the subject field is clickable, and clicking on it makes a new window appear with the actual message. However it is an ajaxgrid, and when i perform a click:
var field = browser.querySelector('#VeryLongIdOfTheField');
browser.fire('click', field, function(){
console.log(browser.querySelector('#VeryLongIdOfTheFieldContainingTheMessage').innerHTML);
});
it returns an error message, saying that undefined has no innerHTML. I suppose its because this action handled with some ajax magic. I am new in this js/nodejs/jquery/.. world, some help needed to enlight me.

Since the data is populated using async ajax, I'm guessing there's a lag between your click and the actual DOM population inside the node. How about waiting for a bit before checking the content inside the node.
browser.fire('click', field, function(){
setTimeout(function(){
console.log(browser.querySelector('#VeryLongIdOfTheFieldContainingTheMessage').innerHTML);
}, 3000)
});
If the time taken is not very predictable, you could also run it inside a loop until you find the content or exit after a reasonable number of retries.

Related

Website loses performance after some jQuery $.ajax calls

I admit I'm quite noob with full ajax websites, and so I'm surely making some mistakes.
The problem is this:
in http://lamovida.arabianessence.com
every page is loaded with an $.ajax call using this function
function getAjaxPage() {
$('a.ajaxc').click(function() {
$("li.page_block").find(".wrapper").fadeOut(400).remove();
hideSplash();
var $thishref = $(this).attr('href'),
$thisurl = $thishref.replace("#!/",""),
$urlArr = $thisurl.split('-'),
$urlOk = $urlArr[0],
$dataOk = $urlArr[1];
$.ajax({
url : $urlOk + ".php",
data : 'id='+$dataOk,
success : function (data,stato) {
$("#content").css({opacity:1}).fadeIn(400);
$("li.page_block").html(data);
$("li.page_block").css('visibility', 'visible');
$("li.page_block").find(".wrapper").css({opacity:0}).show().animate({opacity:1},1000);
var $whgt = $(".wrapper").height(),
$ctop = ( ( $(window).height() - $whgt ) /2 )-40;
$("#content").stop().animate({height: $whgt+40, top: $ctop},1000);
$("li.page_block").css('padding-top',20);
$('.scrollable').jScrollPane();
$('.slider>ul>li').jScrollPane();
getAjaxPage();
},
error : function (richiesta,stato,errori) {
alert(errori);
}
});
});
}
Every time this function is called the content gets loader slower, and after about 20 clicks things get real bad, and the loading time grows and grows.
I tried to analyze the situation using the Google Chrome's Timeline, and I saw that after each click the browser uses more memory. If I comment the getAjaxPage(); row in the "success" section the situation starts to get better, but of course I lose all the internal navigation.
What could I do to avoid this problem?
Many thanks to all!
Every call to $('a.ajaxc').click() is adding new event handler thus every click causes more requests to be made. After the first click, every click will cause two requests. Another click? Another three requests. Etc.
Put the handler outside the function and you will have only one AJAX call per click:
$(document).ready(function() {
$('a.ajaxc').click(getAjaxPage);
});
I also don't see the reason behind calling getAjaxPage again from within the callback, so remove it as well to avoid infinite loop of requests.

Using Form Validation submitHandler to send 2 AJAX requests?

I've got a pretty strong understanding of php, html & css but i've only just started to dive into javascript & jQuery.
The problem i'm facing is that I have a form on a page that I want first to validate, then when it passes validation to submit 2 ajax requests; the first to insert data into a table in my database and the second to run a query on another table and return the result.
I've got the latter working just fine using the submitHandler method to send the ajax request and update a div on my page with it's result. When I added a second ajax call after or before this one it seems to break...
My question is should there be a problem with having 2 ajax calls in the submitHandler, like below, and if so what would be the correct way to go about this, or even a better way?
$("#contactform").validate({
rules: ...
submitHandler: function() {
// First to insert the contact details using input#firstname etc.
var firstname = $("#firstname").value();
var lastname = $("#lastname").value();
var contactString = 'firstname='+ firstname + '&lastname=' + lastname;
$.ajax({
type: "POST",
url: "insertcontact.php",
data: quoteString,
success: function(server_response){
$('#yourquote').html(server_response).show();
}
});
// Second use width & height submitted from previous page for processquote.php
var width = <?php echo json_encode($cleanpost['width']); ?>;
var height = <?php echo json_encode($cleanpost['height']); ?>;
var quoteString = 'width='+ width + '&height=' + height;
$.ajax({
type: "POST",
url: "processquote.php",
data: quoteString,
success: function(server_response){
$('#yourquote').html(server_response).show();
}
});
}
});
I'm using the 'jquery.validate.js' validation plugin. Again my goal is such that once someone has entered valid details on my form, using Ajax their contact data is inserted into the database then the database is queried using fields submitted on the previous page to retrieve a numerical result to display on the page, without a refresh.
Any pointers you could give me would be much appreciated!
Rob
EDIT: Learning Javascript & Jquery simultaneously isn't such a good idea it seems, i've confused: this.value = ''; with $(this).val(''); as shown in the first 2 variable declarations, this is what was causing problems! Thanks for your useful help anyway guys, will upboat for your assistance.
In your first .ajax() call, you are trying to pass it a value in the data: parameter that you have not created yet. I believe you are wanting to send it the contactString instead.
Unless your two queries depend on each other being done sequentially then you should be able to execute them both asynchronously (essentially at the same moment). If you want the second AJAX call to happen after the first one, you could always pass all of your data parameters to insertcontact.php and once the insertion is done, execute processquote.php with the values you already passed through.
Lastly, I wonder if you are meaning to do this, but both of your AJAX calls overwrite whatever is in the #yourquote DOM element and show it. You might want to provide a separate element to put the response in for each of your two requests. Perhaps #yourquoteinserted and #yourquoteprocessed?
Edit: BigRob, from your comment it sounds as if you want to make synchronous AJAX queries, check out the async property of your .ajax() call. This is from the .ajax() documentation:
async Boolean
Default: true
By default, all requests are sent asynchronously (i.e. this is set to true by default). If you need synchronous requests, set this option to false. Cross-domain requests and dataType: "jsonp" requests do not support synchronous operation. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active.
(emphasis mine)
However, I could be wrong about this but you might actually be able to call one asynchronous AJAX method from within the success function of another. If it starts looking too intermingled for you, you might want to extract the inner call into a function. Rough approximation of what it might look like:
$.ajax({url, data:contactString,
success: function(server_response) {
extractedId = server_response; // you can return data many ways
$.ajax({url2, data:quoteString+"&extra="+extractedId,...
});
}
});
If you perform a synchronous call by setting async:false in the first AJAX call, then you could just store the result into an external (to the AJAX call) variable (or if that doesn't work store it in some DOM element temporarily). Then the javascript will pause execution and won't fire your second AJAX call until the first one has returned.
This is all hypothetical for now, though, and just based off of my understanding of how it should work.

Running a javascript after ajax load

I'm using jQuery UI. I'm loading some content in a dialog box over AJAX. After inserting the content from the server, I need to make modifications to the document. I am using the .live() function on my link; I thought this would enable me to use Js after loading the content over ajax, but it's like the content I just loaded isn't a part of the document. Any help very much appreciated.
Are you adding the bindings (lives) in the success function of the ajax call?
If so I had the same issue, I'll try to explain what I figured out:
$.post('callURL', function(data){
// Let's say data returned from server is an ID of a div I have to hide
// by clicking on some_link
$('#some_link').live('click',function(){
$('#'+data).hide();
});
});
This won't work because the code inside the 'live' function is executed on click and at that time the 'data' value is gone.
To make it work I made a global variable 'ID' which I set in the success function and then called in the 'live' function again like this:
var ID;
$.post('callURL', function(data){
// Let's say data returned from server is an ID of a div I have to hide
// by clicking on some_link
ID = data
$('#some_link').live('click',function(){
$('#'+ID).hide();
});
});

TinyMCE not working in http request xhr ajax generated page

So i I have a page that contains links that call an httpRequest. The request calls a php file that grabs data from mysql and pre populates a form which is then returned to the browser/webpage. My problem is that when the page is returned to the browser via the httpRequest/ajax the text area does not display the tinymce editor, it just displays a normal text area. It looks like my request and ajax is working fine the text area just doesn't have the tinycme editor on it.
When i don't use ajax it works fine but when i put it in a separate file and call it via ajax it doesn't bring in the tinymce editor.
Does anyone know how to fix this problem so that my ajax generated page displays the text area with the tinymce editor. Thank you.
Lets presume that your thinyMCE instance is initialized with code below
// initialize tinyMCE in page
tinyMCE.init({
mode: "textareas",
theme: "advanced"
});
and you have some kind of button somewhere in the page. For purpose of this tip, i will not give it any ID but you may. Now, using jQuery you can easily attach event handler to that button which will call through AJAX your server and take content which you want to put tinyMCE editor. Code which will do such job would look somehow like below.
$(function() {
$("button").bind("click", function() {
var ed = tinyMCE.get('content');
ed.setProgressState(1); // Show progress
$.getJSON('/page/12.json', { /* your data */
}, function(data) {
ed.setProgressState(0); // Hide progress
ed.setContent(data["body"]);
}
});
});
});
You can see that on button.click ajax will call url /page/12.json which will return JSON as response. bare minimum of that response could be:
{
title: "Page title",
body: "<html><head><title>Page title</title>......</html>"
}
I attached anonymous function as callback which will handle response from server. and hide progress indicator which is shown before ajax call.
About JSON
JSON is shorten of JavaScript Object Notation. It is JavaScript code!!! So don't be confused about it. Using JSON you can make javascript object which can have attributes you can use later in your code to access particular peace of data which that object "holds". You can look at it as some kind of data structure if it is easier to you.
Anyway, to show you how this JSON can be created by hand look at examples below
var data = new Object();
data.title = "Page title";
data.body = "<html....";
or
var data = {
title: "page title",
body: "<html...."
};
it is very same thing.
If you want to learn more about JSON point your browser to http://json.org.
===== alternative =====
Alternative to json solution could be just plane ajax call to server and response can be plain HTML (from your question I can assume that you have something like this already). So instad of calling $.getJSON you can use $.get(url, callback); to do same thing. The code at the top of my answer will not dramatically change. Instead of geting JSON in response you will get string which is HTML.
----------- BOTTOM LINE -------
I prefer JSON since it can be easily extended later with other attributes, so there is no painful code changes later ;)
Problem here will be that when you return the full page and render it using the ajax response, your tinymce instance has not been shut down before.
In order to do this you can call this small piece of code before you render the ajax response:
tinymce.execCommand('mceRemoveControl',true,'editor_id');
In this case the editor should initialize correctly. You are not allowed to initialize a tinymce editor with the same id before shutting the first one down.
Strangely i ran into this problem yesterday. Following code should work, but YMMV. Trick is to use the correct steps in ajax events. I used the Regular TinyMCE and made use of the jQuery library already included.
Following goes into your tinyMCE initialization tinyMCE.init() . All of the below block should be outside the document.ready.
myTinyInit = {
//.......All essential keys/values ...........
setup : function(ed) {
ed.onChange.add(function( ed ) {
tinyMCE.triggerSave();
}) }
//.....................
};
// Init the tinyMCE
tinyMCE.init(myTinyInit);
This ensures the content is being saved regularly onto the textarea that holds the value. Next step is setting up the request events.
Normally tinyMCE mceAddControl before the ajax post and mceRemoveControl after the ajax success should do the trick. But I found that often does not work.
I used the form as the jQuery selector in my case.
jQuery( '.myForm' )
.find( 'textarea#myTextArea' )
.ajaxStart(function() {
// If you need to copy over the values, you can do it here.
// If you are using jQuery form plugin you can bind to form-pre-serialize event instead.
// jQuery( this ).val( tinyMCE.get( jQuery( this ).attr( 'id' )).getContent() );
}).ajaxSend( function() {
// ! - step 2
// My case was multiple editors.
myEds = tinyMCE.editors;
for( edd in myEds ) {
myEds[ eds ].remove();
}
// tinyMCE.get( 'myTextarea' ).remove();
// strangely mceRemoveControl didnt work for me.
// tinyMCE.execCommand( 'mceRemoveControl', false, jQuery( this ).attr('id'));
}).ajaxSuccess(function() {
// Now we got the form again, Let's put up tinyMCE again.
txtID = jQuery( this ).attr( 'id' );
// ! - step 3
tinyMCE.execCommand( 'mceAddControl', false, txtID );
// Restore the contents into TinyMCE.
tinyMCE.get( txtID ).setContent( jQuery( this ).val());
});
Problems i came across :
Using mceRemoveControl always gave me r is undefined error persistently.
If you get a blank tinyMCE editor, check the DOM whether the ID of the textarea is replaced with something like mce_02, this means that TinyMCE is being initialized again or something is wrong with the order. If so, the tinyMCE is duplicated with each save.
if you are new to JS, I recommend using jQuery with the form plugin, it might be easier for you. But do use the regular non-jquery tinyMCE, as it is well documented.
I fixed this problem by recalling the function after the ajax call. In this part of my ajax:
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("Content").innerHTML=xmlhttp.responseText;
tinymce();
Now it works fine.

Can I make an Ajax request inside an ongoing Ajax request (e.g. on the success callback function)?

I have a jQuery application, a shopping cart, that posts back info to the server, if the text inputfield is changed. This is done in an Ajax request. Now, if the Ajaxrequest is a success, I want to reload the shoppingcart asynchronously. The code is as follows:
$(document).ready(function() {
var jInput = $(":input");
jInput.change(function() {
var vareAntal = $(this).val();
var vareID = $(this).siblings("input#vareID").val();
$.ajax({
type: 'POST',
url: 'checkout.aspx',
data: { 'ID': vareID, 'Antal': vareAntal },
success: function() {
$("#newbasket").load(location.href + " #newbasket>*", "");
}
});
});
});
This works, but only once! If I change the text inputfield, after the page is loaded for the first time, the div with the ID of newbasket reloads asynchronously. But if I try to change it again, nothing happens.
I've tried to do some debugging with Firebug, and the first time I change the text inputfield, it fires a POST-event, and afterwards a GET-event, when the POST-event is succesful. But after that, nothing happens when I change the text inputfield again.
So, how do I achieve triggering the .load() method after each text input change?
I've also tried experimenting with the .ajaxComplete() function, but that, of course, resulted in an infinite loop, since the .load() is an ajax-object.
Instead of .change(func), use .live('change', func) here, like this:
jInput.live('change', function() {
This will make the selector work on any new inputs added as well. When you're replacing the elements like you are currently, their event handlers are lost (or rather, not re-created, because you have new elements). .live() is just for this purpose, it listens for events from old and new elements, regardless of when they were added.

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