Develop Reference

HTML anchor tag's onclick attribute does not call javascript function

We have a DotNetNuke module running in an instance of DotNetNuke 5.4.4, installed on "Server A", a Windows Server 2008 R2 Standard machine with IIS 6.1 and Internet Explorer 11.
We're accessing our DotNetNuke module from "Server B", running Windows Server 2008 Standard, with Internet Explorer 9.
The issue happens when we click an anchor html element that has an onclick attribute, while accessing our module on Server B.
The anchor with the onclick is like:
<a onclick='OpenWindow("/DotNetNuke/DesktopModules/Module/View.aspx?dt=%c2%b2%c2");return false;'
href="http://000.00.0.0/DotNetNuke/DesktopModules/Module/View.aspx?dt=%c2%b2%c2"
target='_blank'
jQuery1431968126278="42">Doc name (SSN-SS-SSNN)</a>
And the OpenWindow function is like this
function OpenWindow(url) {
window.open(url, '', 'top=15,scrollbars=yes,menubar=no,height=800,width=800,resizable=yes,toolbar=no,location=no,status=no');
}
As you can see we have an anchor element, with an onclick attribute, where it is supposed to call the OpenWindow javascript function, then return false, so the default action for clicking an anchor (browse to the href) does not happen.
When we click this link though (ONLY on server B), we get no popup window, no breakpoints in the OpenWindow function are hit, and the browser navigates to the href by opening a new tab (View.aspx). This suggests to me that the OpenWindow function referenced by the onclick attribute is not even running for some reason, even though it is on the anchor element, and works on any other server.
What I've tried
I compared the security settings, web.config files, and DotNetNuke settings between the Server A DotNetNuke and my local developer DotNetNuke instances, and found no differences in setup.
I compared the Server B Internet Explorer security settings to my security settings, and found no differences in setup.
On the advice of comments on this question, I tried changing the anchor tag to a span tag instead (removed href and target attributes), and I am seeing the same behavior. It works on Server A and Dev, but doesn't do anything on Server B now. I think the core issue is that either the onclick attribute is not being recognized, or is being blocked somehow.
I've now gone further and changed most of the <a>...</a> tags into <span>...</span> tags, with specific classes, that I then attach jQuery(...).live('click', ...) handlers to (using jQuery 1.4.2). That is allowing the clicks to work, but I still haven't resolved why the onclick attribute is being ignored.
What's weird..
If I open the developer tools (IE9), then click the "Edit" button to turn edit mode on and off again, all of the onclick attributes on anchor tags and img tags start working correctly, until I reload the page.
If I edit the onclick handler in any way manually through the developer tools, like say removing the return false; from the onclick handler, it will work, but if I put the return false; back to make it like I never changed anything, it stops working again.
What I'm trying to figure out
I am hitting a wall with what to check to figure out this issue. I can't reproduce it on my developer machine, and it works on Server A as well, so the code is working perfectly fine.
I'm thinking there must be a setting that I am overlooking somewhere, but where? I have no idea what else to check at this point, and I'm looking for ideas.

I don't have an exact answer, but I can give you the general idea of what is happening and why.
The two servers are not getting identical content -- perhaps they are pointed at different CDNs, perhaps one has an old file of a JavaScript file somewhere -- you'll have to walk through them one by one.
Something, somewhere, is applying an onclick handler to all of your anchor tags.
At first I thought it was something attached to the body element and targeting your links, but I ruled that out. The fact you can edit the HTML and save it and then the link works means you are detaching whatever was attached to that link element.
I would:
Save the entire web page from Site A
Save the entire web page from Site B
Run a diff tool against the two directories.

Have you tried to call window.open directly from the onclick attribute? It could be that the function is not loaded at the time the link is clicked, so it produce an error, so return false is not called, and the link proceed with its default behaviour (in this case open a tab).
If this is the case, look at the loading order of that function, or try placing it in a different part of your code (maybe within the onload event).
Check if you're showing JS errors in your Internet Options.

It might be a bit childish, but since you are opening a window as a Pop Up there can be issue that the URL from the site might be blocked from the browser. It should work at all times if you just replace
window.open(url, '', 'top=15,scrollbars=yes,menubar=no,height=800,width=800,resizable=yes,toolbar=no,location=no,status=no');
with
window.open(url);

Have you tried modifying your tag to:
<a href='javascript:MyFunction(this);' data-url='YourUrl'>Name</a>
MyFunction: function(obj) {
var element = $(obj);
window.open(element.data("YourUrl"));
}
Note that if the user's browser is configured to open Windows as tabs, there is not a workaround. target="_blank" is the best way that I know of to achieve this and enforcing browser behavior via GP.

Sounds like it's something not in the scope of the code you have provided. You mentioned opening the IE9 dev-tools makes it work, I suggest try adding console -polyfill, something like:
if(typeof(console)=="undefined") {
var console = {
log : function() {},
error : function() {},
debug : function() {}
};
}
Just in case some of your code is outputting things into the console and the JS code stops working after that event. Could be some external library, which after loading starts outputting things to the console - that might work differently on different servers because of caching settings and/or network latency.
NOTE: to test this properly, remember to add this into a SCRIPT tag before you load any JS code or import any external library.

Finding the root of a javascript function on a website

I would like to find the parent JavaScript file for a function, For Example If i was to inspect an element on this page and it has an
"onclick="poster(3459345_5453)"
how could i find out what JavaScript file the function "poster()" is in. So if there is 3 JavaScript files linked to this website, and i don't know which one of them has the function "poster()" how could i find it?
I have already tried right using Ctrl+f in the inspect element area of chrome and was unable to locate the function.

I suggest to use Firefox Firebug. Open Console and just type "poster". It will output function signature. You can hover on it to find out file or click on it to navigate to Script of Firebug. Check out screenshots.
https://blog.gaurangjadia.com/?attachment_id=835
https://blog.gaurangjadia.com/?attachment_id=836
Also, you can put breakpoints and debug your scripts. It is nice and powerful web development tool.
Example is at http://code.gaurangjadia.com/stackoverflow/18551051/

Editing Javascript using Chrome Developer Tools

I am trying to edit javascript on a site using Chrome's Developer Tools. I have read about 30 accounts of how to do this as well as watched a few videos. The fact is, when I go to the sources tab and open the file I want to edit, I can't do anything to it. Is there some step I am missing?
I can create break points, step through, etc... I just can't edit. Was this functionality removed recently?

I know this question is stale, but I just had a similar problem and found the solution.
If you have the file prettified, Chrome will not allow edits. I turned it off and was able to edit. Willing to bet this is/was your problem.

You can edit javascript in the developer tools on the "Sources" tab, BUT it will only allow you to edit javascript in its own file. Script embedded in an HTML (or PHP) file will remain read-only.

It has some limitations:
has to be a JS file. can't be embeded tags in a html page.
it cannot be prettified.

I don't know if you need this to save permanently, but if you need to just temporarily modify the js:
I can copy that javascript I want to modify into a text editor, edit it, then paste it in the console and it will redefine any functions or whatever that I need to be redefined.
for instance, if the page has:
<script>
var foo = function() { console.log("Hi"); }
</script>
I can take the content between the script, edit it, then enter it into the debugger like:
foo = function() { console.log("DO SOMETHING DIFFERENT"); }
and it will work for me.
Or if you have like,
function foo() {
doAThing();
}
You can just enter
function foo() {
doSomethingElse();
}
and foo will be redefined.
Probably not the best workaround, but it works. Will last until you reload the page.

I did search "chrome dev tool edit javascript". This page is the first search result. But it is too outdated, it does not help me.
I am using Chrome 73, this version of Chrome has "Enable Local Overrides" option. Using the function, I could edit a javascript and could run and debug.

My solution:
In the devtools preferences check the Enable local overrides.
Go to network tab, find the file you want to edit, rigth click on it and select Save for overrides (on the sources/overrides tab you need to add a local folder)
The file appears in a new tab on the Sources tab as local copy, so you can edit this file, and after site reload the new (and edited) override file will load on the site!

Multiple Javascript files creating alert boxes

I have been given a project - the one HTML page includes about 45 different javascript files. I am getting alert boxes when I click on some of the elements - which javascript file is making the alert? How do I determine this, preferably which line in the javascript file but I can start with which file...
If this can be done within the web browser (I dont care which web browser) please let me know how... I have looked at the resources tab in chrome but it did not help me.
Thank you.

Use a text editor to replace all
alert
by
console.log
And then use Chrome inspector to see where the logs are.

Include your own javascript file on top of the page and predefine alert with:
alert = function(msg) {
alert(msg); // put breakpoint here
}
Then use the debugger (Firebug in Firefox, or Developer Tools in Chrome) to put breakpoint as described above. The stack trace view in the debugger will show you which script line / file is creating the alert

Use the profiler in Firebug
Console -> Profile -> Click to enable. It will show which all functions are calling, search that function names, and add break points to debug.

How to view all JavaScript functions called in real time?

I want to figure out how a website reloads it's content using AJAX. Therefore i would like to see what JS functions are called in real time because I can't figure out what function is responsible for reloading the page dynamically. How to see all executed functions JS in real time in FF, Chrome, Opera or IE?

Maybe using the 'profile' button in the firebug console tab can give you an indication of the function(s) that are fired. Furthermore you can tell firebug's console to show xmlhttp requests (expand 'console' at the top of the firebug screen. After that, If an ajax request fires, it should be visible in the console. In the 'post' tab in such a request you may be able to infer the function triggering the request, looking at the parameters.

I think what you want is a feature in Chrome:
find the element that is being reloaded and right click,
choose inspect from context menu,
then right click the html of the element (in the bottom firebugish pane),
in the context menu there are options to:
break on subtree modifications
break on attributes modifications
break on node removal
in your case maybe set "break on subtree modifications" on the body tag would do it?
Article on awesome new dev features in chrome: http://www.elijahmanor.com/2011/08/7-chrome-tips-developers-designers-may.html

Install firebug in FF. Visit this link: http://getfirebug.com/

I would do a big search and replace on all the file using a regular expression that matches the function names (something like "function (.*)\((.*)\){") and use that to insert a console.log(functionName) at the beginning the function.
So you search for function (.*)\(.*\){ and replace it with function \1 (\2){ console.log("\1"); (Note: Regular expressions are most likely wrong as I didn't check them - you'll need some testing to get it right).
It seems a bit crazy but it should work. I've used that method to debug a Director Lingo project.
Obviously, make sure you backup the whole project before doing the replacement.

Following on the answer given in case you have access to the source code. With this regular expression you can do a console.log of all function calls:
search for:
function (.*){
replace with:
function \1 { console.log\(("\1")\);

I often using Firefox add-on JavaScript Deobfuscator
https://addons.mozilla.org/en-us/firefox/addon/javascript-deobfuscator/