Develop Reference

Javascript onclick event call to a webservice

Is it possible to call the below script on button click?
<script type="text/javascript" src="https://www.mypaga.com/paga-web/epay/ePay-button.paga?k=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx&e=false"> </script>
I want to use a custom button.

It depends on the logic in script but basically yes you can. See example code below. Then you have to add click event to your button with this function.
function addscript() {
var head = document.getElementsByTagName("head")[0];
script = document.createElement('script');
script.id = 'uploadScript';
script.type = 'text/javascript';
script.src = "upload.js";
head.appendChild(script);
}

It appears you are using the Paga Service api. If you plan on submitting with your custom button, then after the script is loaded, you need to trigger $('#__paga_btn').click() which is can be found from Using the chrome dev tools to inspect element and get the id of the link. #__paga_btn, NB, the script is required to be loaded after the form element. Something like this would suffice for your case
function addscript() {
var head = document.getElementsByClassName("pagalink")[0];
script = document.createElement('script');
script.id = 'uploadScript';
script.type = 'text/javascript';
script.src = "https://www.mypaga.com/paga-web/epay/ePay-button.paga?k=xxxxxxxxxxxxxxxxxxxx&e=false&layout=V";
head.appendChild(script); //Figure out a way to detect when script has loaded.
$('#__paga_btn').click(); // needs to be called after the script as loaded to submit the form.
}
the pagalink node need to be placed below the form element on the page. Since that is where you would actually put the script. The script isn't really customizable since it modifies the dom on load.

Adding javascript to an HTML file and using document ready

So I have a static HTML page that I cannot edit and I need to add jQuery to it and then do some div manipulation (height) on document ready. I found this post which describes how to insert it into a page, which works great. I added that to my javascript file and it inserts it into the page. The problem is that I need to perform some actions on $(document).ready() on that same page, but it says that $ is undefined.
What I would like to do is something like this:
var script = document.createElement('script');
script.src = 'http://jqueryjs.googlecode.com/files/jquery-1.2.6.min.js';
script.type = 'text/javascript';
document.getElementsByTagName('head')[0].appendChild(script);
$(document).ready(function() {
// Resize my div's to the browser window
});
But I can't seem to get it to work. Is this possible? How?

var script = document.createElement('script');
script.src = 'http://jqueryjs.googlecode.com/files/jquery-1.2.6.min.js';
script.type = 'text/javascript';
script.onload = resize; //most browsers
script.onreadystatechange = function() { //ie
if (this.readyState == 'complete') {
resize();
}
}
document.getElementsByTagName('head')[0].appendChild(script);
function resize() {
//code goes here
}

This is due to the ready event firing before the JS jQuery file has loaded. Here is a good tutorial on how to do it.
http://www.ejeliot.com/blog/109
This isn't going to help your page performance though to load your jQuery like this. You should really try to minimize your JS and use as few requests as possible for the best user experience.
Also, you don't need to write
$(document).ready(function() { });
You can just write
$(function() { });

Add jquery script via script file

I have script (myscript.js) which create div and animate div in any HTML page. my script is using Jquery animation function
I am currently using following code (it's sample snippet)
<script src="jquery.js"><script>
<script src="myscript.js"><script>
But is this possible to use only following code which can automatically add JQuery library also?
<script src="myscript.js"><script>

Insert this on top of your myscript.js
var h=document.getElementsByTagName('head')[0];
var s=document.createElement('script');
s.type='text/javascript';
s.src='http://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js';
h.appendChild(s);
but you will have to wait until script loaded using waitforload function
function w4l(){
if (typeof jQuery != "function"){
setTimeout("w4l()", 1000);
return;
}else{
//Do Jquery thing
}
}
w4l();
or just simply copy all jquery.js code file into your myscript.js, AKA merge 2 file into one

To make sure that the rest of myscript.js doesn't get executed before jQuery is loaded, use something like this:
function dostuff() {
//animate elements, etc.
}
var head = document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = 'jquery.js';
script.onreadystatechange = dostuff;
script.onload = dostuff;
head.appendChild(script);
Note: it's a bit unclear why you wouldn't want to explicitly add the jQuery part in your head.

Chrome extension : jQuery.js conflicts in background file conflics with plugins in websites

I am including jQuery in background_page like this,
<script type="text/javascript" src="libs/jquery.js"></script>
Here's the problem:
In websites, where jQuery plugins are used (with jQuery.extend method), they do not work when my extension is installed.
I guess this is because I had my jQuery.js over 'their' jQuery.js' file and all .extend do not work.
So, I thought of adding jQuery.js only when its not avaialable. So, I tried adding jQuery like this,
<script type="text/javascript">
if (typeof jQuery == 'undefined') {
var script = document.createElement('script');
script.type = "text/javascript";
script.src = "libs/jquery.js";
document.getElementsByTagName('head')[0].appendChild(script);
}
</script>
But no luck.
Can someone suggest me a good way to add jQuery.js file in background page.

I really like your approach here, but I would recommend enwrapping your declaration inside of a load event listener:
if (window.addEventListener) {
window.addEventListener('load', init, false);
} else if (window.attachEvent) { // for IE8 and below
window.attachEvent('onload', init);
}
function init() {
if (typeof jQuery === 'undefined') {
var script = document.createElement('script');
script.type = "text/javascript";
script.src = "libs/jquery.js";
document.getElementsByTagName('head')[0].appendChild(script);
}
}
I think the issue may be that at the time you're asking if jQuery is an object, that the DOM hasn't loaded yet.
Alternatively, you can load jQuery via your Manifest File under content_scripts: http://code.google.com/chrome/extensions/dev/content_scripts.html

Found an answer later,
Doing
jQuery.nocConflict
jQ = jQuery.noConflict
and replacing $ with jQ everywhere, solved the problem.
Conclusion: content_scripts can also interfere with webpage javascripts.

Executing a javascript that is injected as a script element via bookmarklet?

I am using bookmarklet to inject a element in document with a custom JS script file. I did it like this:
var newscript = document.createElement('script');
newscript.type = 'text/javascript';
newscript.async = true;
newscript.src = 'http://www.myurl.com/my_js_script.js';
var oldscript = document.getElementsByTagName('script')[0];
oldscript.parentNode.insertBefore(newscript, oldscript);
But I can't figure out how to actually execute it. Can someone tell me how can I execute that JS file?
Note: Since this can be a Greasemonkey script as well, I am tagging this question for Greasemonkey as well.

Script tags are automatically downloaded and executed when they're added to the document. Note, however, that the script you're using may fail if the document you're injecting into doesn't already contain any <script> tags, as oldscript will be undefined.