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.

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.

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.

Change innerHTML of a php DOMElement

In fact during a JS script I change the innerHTML attribute of a DIV, and
this content itself contains JS code.
The problem: This code is not executed js on the page.

If you want to execute some javascript after the page loads, you need to insert it in the head of the document:
var script = document.creatElement('script');
script.src = "path to some script";
script.type = "text/javascript";
document.getElementsByTagName('head')[0].appendChild(script);
or to use eval()

Adding dynamic script resource to a page

In the application I'm developing I need to include some javascript files dynamically after the page is loaded. How to acheive this?

You can load a script resource dynamically using the following function
function loadScript(src){
var script = document.createElement("script");
script.src = src;
document.body.appendChild(script);
}
Here we are creating a script element dynamically and add that to the DOM structure of the page.
If you are using jQuery, you can use the getScript() method to fetch a script resource dynamically.

Add dynamic script resource to a page
function loadScript(src){
var script = document.createElement("script");
script.src = src;
document.body.appendChild(script);
}