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How to avoid '#' sign expansion in `vega#3`

In an HTML script, a call to fetch a package ending in vega#n where n is a version number, is being incorrectly expanded and causing a 404 error. I'm trying to find out why, and to prevent this.
Apologies in advance for the long-winded explanation, but I'm not sure where the problem lies so I'm trying to be as specific as possible.
I'm following the user guide to try and load a vis into a jupyter notebook. This executes the script in-browser, I believe, but for some reason has support for requireJS, which means that global modules aren't correctly loaded when using the import method, which basically uses html's <script> tags to load the module.
This can be worked around by calling define, as described in a similar problem with D3, here: https://github.com/mpld3/mpld3/issues/33#issuecomment-32101013.
I've written this gist to show a working example:
https://gist.github.com/lJoublanc/439e2f687b7aedd6fbdea5adab5cee0f
However, for some reason (either requireJS or something else - my JS knowledge is limited), expands URLs of the form https://cdn.jsdelivr.net/npm/vega#3 into something like https://cdn.jsdelivr.net/npm/vega#3.js?v=20180324103700 which results in a 404 error.
Using the github URL (i.e. without the #3) works fine though.
Any idea if this is requireJS doing this, or the CDN? How would I work around it?

Why don't web workers work?

So, I'm trying to use a web worker in my project to run a long-running process that is currently tying up the UI. I've been to I don't know how many sites trying to get a worker to work, but to no avail.
All of my javascript is kept in separate files and referenced in the HTML file. As a test to get my feet wet, I created a test.js file and put the following code in it:
self.addEventListener('message', function(e) {
self.postMessage('return');},false);
Then, in the UI page's javascript file I placed this code in a function triggered by a button click event:
var w = new Worker('test.js');
w.addEventListener('message',function(e){
alert(e.data);},false);
w.postMessage('hi');
The code is derived from:
html5rocks.com/en/tutorials/workers/basics
Other websites I visited provided similar instructions on how to set up a worker.
For the life of me, I cannot get this to work. When I execute it does absolutely nothing and I seemingly get no errors. Stepping through the code, it appears to create the worker, but I don't see any evidence of the event listener being created and the 'postMessage' event doesn't do anything. I've tried IE11 and Chrome with the same results.
In my research, I came across a part of Chrome's developer tools that revealed the test.js file couldn't be found. Yet, the file is in the same folder as the page's js file. So, I tried adding in the relative directory information as I do in the page's HTML section. That didn't work either.
I then found claims that for security reasons you couldn't have one js file reference another js in the code. It's unclear whether this is a Chrome-only feature or part of some spec.
So, now I'm in a quandary. The worker requires a reference to a separate js file for the code to be executed, yet, the browser isn't allowed to reference another file? How is the worker supposed to work if you aren't allowed to do what it requires to work?
To now, I've successfully pissed away two days trying to get this one seemingly simple function to work. To say I'm mildly frustrated would be an understatement. Being a fairly novice programmer and not understanding every last little nuance about web programming I'm clearly missing a key part of this whole thing.
How the heck is one supposed to make web workers work?

Turns out browsers won't allow local files to be fetched via javascript. Because that means a website can read your personal files! So you need to develop and test your project using a web server. The easiest way to do this for me was to install:
docker-compose
and make sure it works. Then create a file named:
docker-compose.yml
inside root folder of my project with index.html file. Then put this inside the docker-compose.yml file:
version: '3'
services:
nginx:
image: nginx:alpine
volumes:
- .:/usr/share/nginx/html
ports:
- "80:80"
Then inside the root folder of my project run:
docker-compose up
And then in the browser go to:
http://localhost/
And it worked!

I appear to have found a solution, though it escapes me why.
If I use:
var w = new Worker('js\test.js');
the worker doesn't work.
But, if I use:
var w = new Worker('js/test.js');
the worker does work.
I characteristically use the back slash throughout the project to delineate paths without issue. Why the forward slash must be used to set the worker's file location is a mystery. I have seen nothing in any documentation that even remotely addresses that tiny, yet seemingly critical detail.
Thank you, Mr. Starke, for your help!

jQuery on MTurk, why does Chrome report "Unsafe JavaScript attempt to access frame with URL"?

I'm doing a couple of things with jQuery in an MTurk HIT, and I'm guessing one of these is the culprit. I have no need to access the surrounding document from the iframe, so if I am, I'd like to know where that's happening and how to stop it!
Otherwise, MTurk may be doing something incorrect (they use the 5-character token & to separate URL arguments in the iframe URL, for example, so they DEFINITELY do incorrect things).
Here are the snippets that might be causing the problem. All of this is from within an iframe that's embedded in the MTurk HIT** (and related) page(s):
I'm embedding my JS in a $(window).load(). As I understand it, I need to use this instead of $(document).ready() because the latter won't wait for my iframe to load. Please correct me if I'm wrong.
I'm also running a RegExp.exec on window.location.href to extract the workerId.
I apologize in advance if this is a duplicate. Indeed - after writing this, SO seems to have a made a good guess at this: Debugging "unsafe javascript attempt to access frame with URL ... ". I'll answer this question if I figure it out before you do.
It'd be great to get a good high-level reference on where to learn about this kind of thing. It doesn't fit naturally into any topic that I know - maybe learn about cross-site scripting so I can avoid it?
** If you don't know, an MTurk HIT is the unit of work for folks doing tasks on MTurk. You can see what they look like pretty quick if you navigate to http://mturk.com and view a HIT.
I've traced the code to the following chunk run within jquery from the inject.js file:
try {
isHiddenIFrame = !isTopWindow && window.frameElement && window.frameElement.style.display === "none";
} catch(e) {}

I had a similar issue running jQuery in MechanicalTurk through Chrome.
The solution for me was to download the jQuery JS files I wanted, then upload them to the secure amazon S3 service.
Then, in my HIT, I called the .js files at their new home at https://s3.amazonaws.com.
Tips on how to make code 'secure' by chrome's standards are here:
http://developer.chrome.com/extensions/contentSecurityPolicy.html

This isn't a direct answer to your question, but our lab has been successful at circumventing (read hack) this problem by asking workers click on a button inside the iframe that opens a separate pop-up window. Within the pop-up window, you're free to use jQuery and any other standard JS resources you want without triggering any of AMT's security alarms. This method has the added benefit of allowing workers to view your task in a full-sized browser window instead of AMT's tiny embedded iframes.

'$ is not defined' in code following jQuery include

I'm getting the familiar '$ is not defined' error in my JavaScript for the following line in one of my javascript files...
$(document).ready(function() { … }
Normally this is because I've forgotten to include jQuery, but not this time! I have included it, and it is the first include in the page. This error happens in included JavaScript files, and also in any code within tags, all of which come after the jQuery include. It also doesn't happen all the time, maybe half the time when I refresh the page.
I've also used jQuery quite a lot and never seen this before, so I am quite confused.
Edit:
Looking at the Net tab in Firebug, jQuery is being requested and I get a 200 response but nothing is sent back in the response body. If I open the file directly in a new tab or whatever, I get an empty document. Firefox seems to think the file is cached but the data size is 0. Cache control is 'no-cache'. Confused.
Edit 2:
Opened jQuery file in VisualStudio, saved jQuery file with no modifications, everything works perfectly now. Still totally confused.

Are you sure that jQuery is actually being loaded into the browser? It sounds like it really isn't. You should use Firebug or Fiddler to check all the http requests to see if it is actually being downloaded.
Here's a screenshot of how you can check this using Firebug.

Are you using Wordpress or some sort of CMS? If so, their version of jQuery may have of code at the end which calls jQuery.noConflict(). You can read about this method here: http://api.jquery.com/jQuery.noConflict/
This means that whenever you want to use the $ function, you need to use jQuery instead.
For example...
Instead of
$("p").addClass("awesome");
You would do
jQuery("p").addClass("awesome").

How to help the debugger see my javascript, or how to best refactor my script to help make it debugger-friendly?

I have an ASP.NET MVC project that uses some simple AJAX functionality through jQuery's $.get method like so:
$.get(myUrl, null, function(result) {
$('#myselector').html(result);
});
The amount of content is relatively low here -- usually a single div with a short blurb of text. Sometimes, however, I am also injecting some javascript into the page. At some point when I dynamically include script into content that was itself dynamically added to the page, the script still runs, but it ceases to be available to the debugger. In VS2008, any breakpoints are ignored, and when I use the "debugger" statement, I get a messagebox saying that "no source code is available at this location." This fails both for the VS2008 debugger and the Firebug debugger in Firefox. I have tried both including the script inline in my dynamic content and also referencing a separate js file from this dynamic content -- both ways seemed to result in script that's unavailable to the debugger.
So, my question is twofold:
Is there any way to help the debugger recognize the existence of this script?
If not, what's the best way to include scripts that are used infrequently and in dynamically generated content in a way that is accessible to the debuggers?

I can not comment yet, but I can maybe help answer. As qwerty said, firefox console can be the way to go. I'd recommend going full bar and getting firebug. It hasn't ever missed code in my 3 years using it.
You could also change the way the injected javascript is added and see if that effects the debugger you're using. (I take it you're using Microsoft's IDE?).
In any case, I find the best way to inject javascript for IE is to put it as an appendChild in the head. In the case that isn't viable, the eval function (I hate using it as much as you do) can be used. Here is my AJAX IE fixer code I use. I use it for safari too since it has similar behavior. If you need that too just change the browser condition check (document.all for IE, Safari is navigator.userAgent.toLowerCase() == 'safari';).
function execajaxscripts(obj){
if(document.all){
var scripts = obj.getElementsByTagName('script');
for(var i=0; i<scripts.length; i++){
eval(scripts[i].innerHTML);
}
}
}
I've never used jquery, I preferred prototype then dojo but... I take it that it would look something like this:
$.get(myUrl, null, function(result) {
$('#myselector').html(result);
execajaxscripts(result);
});
The one problem is, eval debug errors may not be caught since it creates another instance of the interpreter. But it is worth trying.. and otherwise. Use a different debugger :D

This might be a long shot, but I don't have access to IE right now to test.
Try naming the anonymous function, e.g.:
$.get(myUrl, null, function anon_temp1(result) {
$('#myselector').html(result);
});
I'm surprised firebug is not catching the 'debugger' statement. I've never had any problems no matter how complicated the JS including method was

If this is javascript embedded within dynmically generated HTML, I can see where that might be a problem since the debugger would not see it in the initial load. I am surprised that you could put it into a seperate .js file and the debugger still failed to see the function.
It seems you could define a function in a seperate static file, nominally "get_and_show" (or whatever, possibly nested in a namespace of sorts) with a parameter of myUrl, and then call the function from the HTML. Why won't that trip the breakpoint (did you try something like this -- the question is unclear as to whether the reference to the .js in the dynamic HTML was just a func call, or the actual script/load reference as well)? Be sure to first load the external script file from a "hard coded" reference in the HTML file? (view source on roboprogs.com/index.html -- loads .js files, then runs a text insertion func)

We use firebug for debug javascript, profile requests, throw logs, etc.
You can download from http://getfirebug.com/
If firebug don't show your javascript source, post some url to test your example case.
I hope I've been of any help!

If you add // # sourceURL=foo.js to the end of the script that you're injecting then it should show up in the list of scripts in firebug and webkit inspector.
jQuery could be patched to do this automatically, but the ticket was rejected.
Here's a related question: Is possible to debug dynamic loading JavaScript by some debugger like WebKit, FireBug or IE8 Developer Tool?