Javascript not working on content pulled from another source - javascript

I'm pretty sure this is a dumb issue, but I searched and could not find a similar/equal scenario.
So, I have a main PHP page in which I include several Javascript files in the head section of the HTML. Then at some point I grab content (HTML + Javascript) from an outside source via file_get_contents and output it to the main page.
This new output will pick up the CSS styles from the main page normally, but any Javascript code that relies on the ones loaded at the main will not work. Even if I put the Javascript needed inside a document.ready in the main page, it will still not work.
Just to exemplify the code:
<html>
<head>
<link href="style.css" rel="stylesheet">
<script src="somejslib.js"></script>
</head>
<body>
Some HTML here generated by PHP
<?php
$content = file_get_contents('http://whatever/page');
echo $content;
?>
</body>
In the grabbed content I will have something like:
<div>
<form>
<input type="text" id="bla">
</form>
</div>
<script>$('#bla').datepicker({ somecodehere });</script>
The datepicker was included in the libs loaded in the main page, but will not work, no matter where I put this code.
Any hints?
P.S: the only way it DOES work is if I include - again - all the Javascript libs inside the new content, which of course is not a solution.

make sure you attach the listeners after the external content is loaded or use the on() event handler
http://api.jquery.com/on/
P.S. I now see your code is actually missing the document.ready and thus not waiting for the document to be loaded before executing. I'm not sure which of these applies to your actual code as you only posted an example. If you pull the content in via an ajax for example apply the first solution otherwise just wrap things up in a document ready

Solved.
Apparently it was my mistake all along. I was loading Jquery multiple times (different versions, also).
It seems that not all versions of jQuery can take care of this situation.

Related

HTML / jQuery: How to properly include external jQuery file

I am new to JS and programming in general and hope someone can help me with this.
I am currently working on building a website where every page has its separate HTML / PHP file.
jQuery and my global / general JS functions are included in the footer of all these pages through a separate includes file "footer.php".
So far everything works as intended.
Now I have some pages that will use specific jQuery functions so I want to load the corresponding JS only if such a page is loaded.
To do this I saved the corresponding codes in separate JS files (e.g. nameOfExternalJsFile.js) and wrapped everything in there in the following:
$(document).ready(function(){
// ...
});
I then made the following updates to the corresponding PHP pages (example):
<head>
<?php
require_once("includes/header.php");
?>
<!-- here I want to include the specific jQuery functions -->
<script src="includes/js/nameOfExternalJsFile.js"></script>
</head>
<!-- ... -->
<!-- here I include the main JS functions -->
<?php require_once("includes/footer.php"); ?>
I have two concerns with this:
I am not sure if this is the right way of including such files since
I need to have them available on document ready.
I include my main JS in the footer since I was told this improves
performance but can I then include jQuery functions in the header at all ?
Can someone let me know if this is correct or if I should change anything here ?
Many thanks for any help with this.
Wrapping the functions in $(document).ready automatically takes care of this concern. From the JQuery documentation on document.ready.
A page can't be manipulated safely until the document is "ready."
jQuery detects this state of readiness for you. Code included inside
$( document ).ready() will only run once the page Document Object
Model (DOM) is ready for JavaScript code to execute.
Technically it doesn't matter whether you include the scripts in the header or the footer, as long you load JQuery first and your script second.
That said, it's generally recommended that both scripts go just before the closing body tag to increase performance as you suggested. There are some articles that discuss this like this post from performance expert Steve Souders and this guide from the Yahoo! Exceptional Performance team.
You should load the $(document).ready(...) stuff only after you have loaded jQuery, that is, in the footer file, after the jQuery <script> tag, like this :
<script src="includes/js/jQuery.min.js"></script>
<script src="includes/js/nameOfExternalJsFile.js"></script>
It`s good practise to locate all the JS files in the end of the body
<html>
<head></head>
<body>
... Some HTML
<script>SomeScripts</script>
</body>
</html>
</pre>
If you want to be sure that your external scripts are loaded after page load use:
$(function(){
/* Your code from the scripts */
});
You can change the content of footer.php to include /nameOfExternalJsFile.js manually at the bottom of the page. That´s the safest way to do it because you may load jquery before loading others scripts.

AJAX doesn't override already loaded scripts?

I'm using a version of jquery-ui-widget, 1.10.3, that works well with ajax-loaded page fragment#1 but triggers an error with page fragment#2 if fragment#2 was loaded after fragment#1.
This is strange because even if I try and override 1.10.3 with 1.8.21 when ajax-loading fragment#2 (yes I realize this is a bad hack), the code that uses the widget factory still tries to use 1.10.3 and so causes an error.
Note that this is not a problem during normal page load as 1.8.21 is outside of my ajax div id="ajax_content" and so is loaded every time.
How can I override 1.10.3 during ajax?
<html>
<div id="ajax_content">
Page fragment #1 content
<script src="jquery-ui-widget.1.10.3.js"></script>
</div
<script src="jquery-ui-widget.1.8.21.js"></script>
</html>
VS.
<html>
<div id="ajax_content">
Page fragment #2 content
<script src="jquery-ui-widget.1.8.21.js"></script>
//having this script here or not has no effect if 1.10.3 was already loaded
</div>
<script src="jquery-ui-widget.1.8.21.js"></script>
</html>
version of jquery-ui-widget won't have an effect. Rather the cause of your problem is that the script added to the innerHTML of your div id="ajax_content" will not execute.
A script added dynamically (which maybe received as a response of an ajax request or that dynamically added to the innerHTML using js or jQuery) doesn't execute. Also it is not recommended as per #Kevin B's comment. I worked around the same problem by either of the two solutions below:
Load entire script initially
Load a new page with the script in the head tag
You may disagree with the second solution here saying that the question was about the script received as a ajax response while I am suggesting you to rework your approach and use a separate page instead. This may not be appropriate to do in your scenario due to various reasons but if the only reason preventing you from doing so is that this will cause code duplication then you may explore using something like jsp:include.

How to run scripts loaded dynamically with javascript

I was wondering if there is a way to execute script within a ajax dynamically loaded content.
I've searched the web and this forum also an find a lot of answers, like
[Running scripts in an ajax-loaded page fragment
[1]: Running scripts in an ajax-loaded page fragment [1]
But none of this seems to work fine for me.
I'm not experienced as the author of the quoted post, so maybe we can find a solution more simple and quite for everyone.
For now i've implemented a tricky turnaround that smell to much of an hard-coded solution that is:
//EXECUTE AJAX REQUEST LET'S SAY SUCCESSFULLY,
$ajax([..]) //THEN
.ajaxSuccess(function(){
// LOCATE ANY OBJECT PRE-MARKED WITH A SPECIFIC CLASS
$(".script_target").each(function()
{
//DO SOMETHING BASED ON A PRESET ATTRIBUTE OF THIS SPECIFIC ELEMENT
//EXAMPLE: <div class=".script_target" transition="drop_down">...</div>
//WILL FIRE A SCRIPT RELATED TO drop_down CASE.
});
});
I know this is an ugly solution but i didn't came up with nothing better than this.
Can you help to improve this method?
Maybe there's a way to let the browser fire script within the loaded page automatically?
PS. I'm not going to use the eval() method if it's not the last solution, cause both security leak and global slowdown, AND be aware that the script launched need to modify objects loaded in the same fragment of the script.
Thanks in advance.
If I understand you correctly :
you use "load" to retrieve html content from the server, and you add it to the page.
later, you do an ajax call, and on the return of the ajax call, you want to act on the markup you added earlier
but, depending on the markup retrieved, you want to do something different in the ajax callback
So another question : before you load the markup, do you know what logic will be behind it, or do you actually need to "read" the returned HTML to understand what it will be used for ?
Otherwise maybe something like this would work :
In the callback of the "$.load" function, use $.data() to attach more information to created dom object
In the ajax callback, you should be able to access the "added" markup (with a class like you did, or with an id if possible), and read to "data" to known which behavior you should have ?
Hopefully I got your problem right, it could help if you were able to create a jsfiddle or something, just to make sure we understand it.
Hoping this helps.
EDIT : After your comment, it might be related to the selector you use when calling $.load().
There is a "Script Execution" section in the $.load documentation : http://api.jquery.com/load/ , that explains that the scripts are not executed if you add a selector in the url, like this :
$('#b').load('article.html #target');
Could this be your issue ?
Also, if possible, you could try and change your site so that instead of having the js code of each "page" of the gallery inside the page, you put it inside a separate javascript file, that you load at runtime (for example with require js).
This way, "loading" a page would be something along the lines of :
$.load("url_of_a_page_markup.html", function () {
require(["url_of_the_javascript_module.js"], function (TheJsModuleForThePage) {
TheJsModuleForThePage.doSomething();
});
});
If you structure your JS modules in a consistent way, and you define a convention for the name of markup and js files, you can generalize things so that a "gallery" manager deals with all this code loading, and you'll end up with well isolated js modules for each page.
Hoping this helps.
If you want to run a script in a ajax loaded page fragment you can use try to use jQuery.load function.
Have you considered a module loader like require.js or Lab.js?
There are many other people asking similar questions:
does anyone knows good ajax script loader
Where are scripts loaded after an ajax call?
getting jQuery scripts and content through ajax dynamically
dynamic script loader in JS
Edit: I think I misread your question. Will try and come up with a better answer. Sorry!
Best of luck to you!
I came across this same issue when I dynamically loaded some HTML to use inside a JQuery UI dialog (a help function for my application).
$('#helpMessage')
.load('./help/' + helpFile, function () {...do stuff after loading});
To make things simple I wanted to combine the unique script related to the help page within the HTML fragment that I load. Using the examples on the JQuery UI page I created a dialog with a Jquery UI button element.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery UI Button - Icons</title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.10.4/themes/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.9.1.js"></script>
<script src="//code.jquery.com/ui/1.10.4/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css">
<script>
(function() {
$('#myButton') // My button element
.button() // Initialize it as a JQuery UI button object
.click(function (){ // Hook up the button click event
$('#correct')[0].play(); // to play a sound in an <audio> tag
});
});
</script>
</head>
<body>
This is my help file, this is my code. This is for reading, this is for fun.
<button id="myButton">Button Text</button>
</body>
</html>
The dialog would load and the HTML displayed, but the embedded script did not execute.
I realized that one simple change would fix it. The script is embedded in an anonymous function (a best practice and part of the JQuery UI demo code). By immediately invoking the anonymous function the script executed when I loaded the HTML fragment into my main page.
This:
<script>
(function() {
...
});
</script>
Became:
<script>
(function() {
...
})(); // Immediately invoke
</script>
Niceness.

asp.net 2.0 site and location of <script/> tags causing problems/conflicting

I have no idea how to describe this accurately/intelligently because it seems to be completely impossible, yet there must some reason for it.
I am trying to leverage jquery, jquery-ui, qtip (tooltip for jquery) and highcharts (javascript charting), but for purpose of post I could just as easily been only using jQuery and jQuery-UI.
If I include my <script/> tags at the bottom of my <head/> element I get an error trying to call the .slider() extension to configure my sliders. But if I put the <script/> tags right before the closing of my <body/> element then everything works. To illustrate, the following will not work (obviously some pseudo code below):
<head>
<script jquery.js/>
<script jquery-ui.js/>
</head>
<body>
... html ...
<script type="text/javascript">
$(document).ready(function () {
$(".slider").slider( { .. options .. } );
} )
</script>
... more html *including* the .slider elements
</body>
However, if I move the two jQuery script tags to be right above the </body> closing element things work. When the script tags are in the head element and I debug my application, basically the page does appear to have completely loaded and Visual Studio highlights the line calling the .slider() function saying it doesn't know what slider() is. Looking at the call stack, it appears to be correctly calling it from the document ready function...the mark up all appears to be there as well, making me believe the document truly is ready.
Now I didn't include things that are required by asp.net 1.1/2.0 site in my pseudo code, namely a <form/> element with runat="server' and the use of a <asp:ScriptManager/> tag (we needed that for parsing monetary values from different cultures leveraging Microsoft Ajax). I can't believe they would be causing the problem, but maybe they are. Additionally, asp.net injects several of its own script sections (i.e. for validation, post back, etc.)
Regarding the form tag...all the html and document.ready markup would be inside the form tag, while the script tags are always outside of the form tag (either above it, in the head or below it at the bottom of the body).
Obviously I could leave the script tags at the bottom, and I very well may end up doing that, but I am trying to get a clean 'template site' of which to use when creating new client sites and it just feels wrong that I have a restriction forcing me to put those tags at the bottom of the html. I'm sure our framework code (or maybe asp.net's) is simply inserting something that is causing problems/conflicts with jQuery, but I don't really know how to go about debugging/diagnosing what that problem is. So if anyone has any suggestions I'd greatly appreciate it.
It looks like jQuery 1.3.2 is being loaded by ASP.NET (see your second WebResource.axd). The two library versions are overwriting each other. Thus the reason it works when you load 1.6.2 at the end of the page.

Loading a script in the <body> section

I have a javascript for a specific page that I do not wish to be loaded in my header section. Is it possible to load it in the section of the HTML.
Currently I have all my js code inside the but I want to remove it to a seperate js file that I can load.
I tried using this but it did not work.
<script type="text/javascript" src="<?php echo base_url();?>js/jquery-1.5.1.min.js"></script>
Thanks
Q1 : I have a javascript for a specific page that I do not wish to be loaded in my header section. Is it possible to load it in the section of the HTML.
-Yes you can load javascript any where you want, if writing inline code then make sure you add script tag around your code.
-also you can request files like in body
Q2: Currently I have all my js code inside the but I want to remove it to a seperate js file that I can load.
-- no problem in that, thats even better practice.
Q3 Requesting external file
to request external files you write below written fashion
<script src="http://file_name.js" type="text/javascript"></script>
It's not only possible (ref), it's frequently a good idea.
Putting your scripts as late in the page as possible, which frequently means just before the closing </body> tag, means the browser can parse and display your content before stopping to go download your JavaScript file(s) (if external) and fire up the JavaScript interpreter to run the script (inline or external).
Putting scripts "at the bottom" is a fairly standard recommendation for speeding up the apparent load time of your page.
Yes it is possible. Try and see.
For debugging, hardcode the jquery full path.
It is sometime recommended to load it at the end of the of the body, to make the main content of the page load faster.
Is it possible to load it in the section of the HTML.
Yes.
From the spec:
<!ELEMENT BODY O O (%block;|SCRIPT)+ +(INS|DEL) -- document body -->
SCRIPT is among the elements that may be a child of the BODY elements. Numerous other elements may also have SCRIPT children.
<script type="text/javascript" src="<?php echo base_url();?>js/jquery-1.5.1.min.js"></script>
When I run echo base_url() I get my the hostname of my server. This would result in a URL such as example.comjs/query-1.5.1.min.js. You probably should drop that PHP snippet entirely and just use: src="/js/jquery-1.5.1.min.js" which would resolve to http://example.com/s/query-1.5.1.min.js.
Yahoo engineers recommendation for higher performance is to include your scripts at the end of your HTML, just before </body> tag. Therefore, it's even better.
To see where the problem is, you gotta first make sure that your js file is loading. User Firebug and go to scripts tab. Do you see your script? If not, then something is wrong with your path.
it should work...
Did you try to view the generated source and see if the PHP code indeed generated the right path?
beside that, it is recommended to load jQuery from a CDN such as google's :
https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js

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