Develop Reference

basic javascript alert not working in Intel XDK code editor

I'm starting fresh with a new blank Intel project and I haven't even started coding yet. I'm just setting up my file tree and making sure the html and javascript pages are connected via the right anchors and script paths. My first .js file won't work though.
I've included a screen shot of test code and the errors. I know the syntax is correct because it works when I put it in <script> tags in the index.html file.
I'm getting "document not defined" and "alert not defined" errors or the js page though. I don't know what that means.
I've considered that my script tag src path in the index file is incorrect, but all the paths are relative in the commented out template script tags intel provides on the index page right out of the box, so why would I have to use an absolute path?
My path is: js/Test.js and it's the last script tag before the body.
Index.html file
*****UPDATE****
So I've tried a few things and it's still not working but I HAVE managed to get my errors down to just one inexplicable "missing semicolon", which will turn into an "unnecessary semicolon" error if I place it.
Any way as per the first screen shot you'll see that I wasn't placing the document object inside of an explicitly declared variable. Once I did that and accessed it through dot syntax instead of an equal sign then I stopped getting the error. I included this screenshot to show my work before I made the changes.
so the problem I went on to have is that unless every function or dom object was declared with "Var", I'd get an error. This includes the alert() function which I don't think I've ever seen needing to be declared that way, but I gave the code editor what it wanted and this last screenshot is the results. It's not working, BUT I'm not getting the errors I was before, except for the missing/unnecessary semicolon paradox. Removing it or including it throws an error.

JavaScript can be loaded before or after the HTML, however the way it is done is slightly different depending on how you do it.
For example if you wish to include your JavaScript files within the head of the HTML file then you must wrap your JavaScript code with either DOMContentLoaded or jQuery's $(document).ready().
The common misconception of using window.onload will not fix the issue where the elements have not loaded in correctly.
The Mozilla Developer Network states on this page:
The DOMContentLoaded event is fired when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading. A very different event - load - should be used only to detect a fully-loaded page. It is an incredibly popular mistake to use load where DOMContentLoaded would be much more appropriate, so be cautious.
That quote in itself should prove that onload should not be relied on if you want the full DOM to be loaded properly before you start manipulating it. Instead you should do the following:
Vanilla
document.addEventListener("DOMContentLoaded", function (e) {
/** DOM has been fully loaded here, so manipulation can begin. **/
/** Your code here. **/
});
jQuery
$(document).ready(function () {
/** DOM has been fully loaded here, so manipulation can begin. **/
/** Your code here. **/
});
Click this link to see the difference between vanilla and jQuery.
The second way you can load JavaScript is by having all the script tags within the body but after all the HTML, that way it is guaranteed to load after the HTML.
Example
Try this working example I quickly coded up.
HTML
Replace the content within the body tag of your HTML to the following:
<button id="myJsTest">Click Me!</button>
<div id="clickCounter">Click Count: 0</div>
Replace the contents of your JavaScript with the following:
JavaScript
document.addEventListener("DOMContentLoaded", function() {
var clickCount = 0;
document.getElementById("myJsTest").addEventListener("click", function() {
clickCount++;
document.getElementById("clickCounter").innerText = "Click Count: " + clickCount;
});
});
Then use the Emulate tab in Intel XDK to test it.
Additional Information
When I use Intel XDK and I have an error, I quickly load the file in to the browser and check the console. It can be a really helpful and effective way of squashing those pesky little bugs.
Try using window.alert as alert is defined in the window object.

The reason you're seeing all those "error" messages in the editor window is because you've got the various JSLint/Hint tools loaded in the editor. They're trying to keep you honest and save you lots of time in the debugger chasing potential syntax errors.
The editor inside the XDK is Brackets, it is using standard Brackets extensions to provide those JSLint/Hint tools. You can download it and run it standalone on your system and edit directly within it, you don't have to use the editor inside the XDK (or you can use any other editor you like).
Because the Lint/Hint tools only look at one file at a time, and because your app is normally spread over multiple files, they don't know much about about what's defined in your other files. Likewise, those hint/lint tools need to be told that you're using some of the standard global methods and properties that are expected to be found in a browser (but which may not be found in other JavaScript environments, because JavaScript is no longer limited to just a browser environment -- in fact, your XDK app, aka Cordova app, runs inside a "webview" not in a browser, but that's another story...)
So, you should follow some standard practice of setting up your JSHint/Lint directives at the top of your JS files. For example, this is a good starting point:
/*jslint browser:true, devel:true, white:true, vars:true */
/*global $:false, intel:false */
See the JSHint documentation for details... and see the "Blank Cordova Starter App" in the "Start a New Project" section of the Projects tab for a better blank template to start (there is no real difference between a blank template and a demo app, they are structured identically).
For a more complete and even more instructive app, see the "Hello, Cordova" sample app. Both of those apps can also be found on the Intel XDK GitHub repo.

You are adding the js file that is <script src="js/Test.js"></script> inside header tag.
So js will be first loaded and and it will attach all events to it. But when js is loaded button id="jsTest" is not present because DOM is not loaded.
Solutions :-You can follow either of the approach
Add your js files after DOM is ready
<body>
<button id ="js/Test.js">Test JS</button>
// other HTML tags
<script src = "js/Test.js></script>
</body>
Use window.onload
The load event fires at the end of the document loading process.
window.onload = testJsFile(){
//Your code goes here
}
I will prefer to use the first approach since that also address other issues like page loading time

Try to put the line outside your JS function
document.getElementById(......
inside your html page between
<script>HERE</script>
If this is still no working. Try to add onClick attribute to the button like this:
<button id="" onClick="testJsFile()">
Its also good to use google chrome element inspection while devlopping cuse it will give you error msg for all these things.

Code inside script tags not running in MVC3 Application (Razor View Engine)

The code inside the script tag in my application contains all the code that makes AJAX calls, validation and even a jqgrid. I started off with the problem - the jqgrid not rendering at all on the screen - and then I found that no method inside the script is getting called and if any method is called with a click event or something else, it throws an error telling that it's not a defined property. What could be my problem?
I am not using any layout page so I copied the references from the master page to the page under question itself. It didn't work.
All the other pages in the application also have jqgrid and they are all rendering properly.
SOLUTION:
The script's open tag had language="jscript" type="text/jscript". Once I changed both to javascript everything was fine.

Not sure if this applies, but are you waiting for the DOM to be rendered before running your script?
$( document ).ready() ?

Changes made from js files are not being rendered and cannot be debugged

I have a html page (inicio.html) which loads some js scripts. Then from a js script there is a navigation to another page in a different html file (test.html) and a different set of js files.
The problem is that when I do the changePage ($.mobile.changePage("test.html");) and the new page is loaded the new js files are kept in files like
http://localhost:8080/cdmWEB/resources/scripts/jquery/2.0.3/jquery-2.0.3.min.js/eval/seq/2
The js functions are being executed because the console.log messages in them are shown. But the changes the js scripts should do in the page are not rendered and the js cannot be debuged (using firebug).
I am loading the js scripts with the tag in the html file, but I have also tried the $.getScript function with the same result.
I am using jQuery 2.0.3 and jQuery-mobile 1.3.1.
From what I saw the reason why the js files are kept like that is because they are retrieved using ajax. Is there a way to prevent this and retrieve the file "normally"? or is there something I am missing (probably)?

Have a look here:
Jquery Mobile - $.mobile.changepage not loading external .JS files
You should consider loading the needed JS in the main page, and not in the page your changing to.

I ended up using window.open('test.html','_self','',true); to make the transition. This loads the new scripts when the transition is made and the jquery appends keep working fine.

Why would javascript work embedded in html page, but not in external script?

I am using a simple script, and when the script is embedded into the actual html page it works just fine, but when it is thrown into an external .js the script no longer works, i am not seeing any errors in the console, it is a jquery delegate function, and i know that the external script is working, because there are other scripts in it that are currently working just fine.
just wondering if there is a cause to this problem, or if anyone else has encountered this.

If you're embedding the script in the body of the HTML document, and if your script relies on the existance of elements before the script in the body, then that same script wouldn't work if loaded as an external resource since that code would be executed before the HTML DOM is built.
To make sure your scripts work in either case, wrap any startup code in a $(document).ready(...) method.

jQuery append doesn't work fully with <script> tag

Appending a script element using jquery rather than putting it in the html by hand seems to lead to very different results. For instance
snaphtml = '<script src="http:\/\/seadragon.com\/embed\/lxe.js?width=auto&height=400px"><\/script>';
$('#content').append(snaphtml);
destroys the layout of my page, but putting the script element in the page directly works fine.
I have posted a test case online:
Working example with script in html.
Broken example with script appended via jquery.
The second div should not be deleted / invisible once the silverlight object is added.
Ideas?

I would recommend you to use $.getScript method for loading external script files programmatically:
$.getScript('path/to/script.js', function() {
alert('Script loaded.');
});
The script load is made asynchronously, and as you see in the above example, you can specify a callback function that will be executed when your external file has been loaded and is ready to use.

Tristan, you will not be able to include the script you reference dynamically onto the page after it has finished loading. The external script is using document.write which will only work correctly when called before the page has finished loading. This is why your static implementation works fine, and your dynamic one tears the page apart.
You might want to put together a dummy HTML file that just has a basic HTML structure and this script in it already. Then dynamically add an iframe to your page that loads the HTML. There are even more dynamic ways to make it work with an iframe, but that would be the easiest.

Try to use $.getScript:
$.getScript("http://seadragon.com/embed/lxe.js?width=auto&height=400px");
Edit:
The provided script is using document.write, which is likely causing your problems: you cannot add it dynamically at the middle of the page. Try loading SeaDragon as shown here:
http://www.seadragon.com/developer/ajax/getting-started/

try to break script tag like
snaphtml = '</sc'+'ript>'