Develop Reference

Is .js extension needed for Javascript files in browser?

Can things like <script type="text/javascript" src="/actions/generateScript"></script> be used without troubles?
It's kinda hard and tricky to setup server for processing urls with extensions, so maybe I just don't need them.

No, it's not needed. Browser just tries to download resource from src and execute it as JS code.
I once have use .php file as CSS source and it worked fine

No, since you already have "script type="text/javascript" the browser knows you are attempting to load a .js file. In addition modern browsers will run javascript regardless.

How do I install ReactJS locally?

I've tried reading over the "guide" on their website, and none of it makes sense to me. I thought it'd be the same thing as JQuery, but apparently I'm missing something.
I have this appended in my html document (where it's appropriate of course):
<script src="respond.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://unpkg.com/react#latest/dist/react.js"></script>
<script src="https://unpkg.com/react-dom#latest/dist/react-dom.js"></script>
<script src="https://unpkg.com/babel-standalone#6.15.0/babel.min.js"></script>
<script src="app.js"></script>
<script type="text/babel" src="app_2.js"></script>
As you might have guessed, I'm using Adobe Dreamweaver to develop my webpage.
That is what the first script element is for. The second being for JQuery.
After running an "example" for ReactJS with JSX, I found the three following script elements in the html document. That, to me, tells me that all I had to do in order to get it working is link those in as well.
Long story short: it didn't work. I tested it on Firefox and Chrome.
The thing I'm still scratching my head over is the error I receive when trying to view the remote files for the ReactJS-related files (on DW):
Not found: package "filename%version"
Where filename is the name of the JS file and version is the version (I'm assuming).
This only occurs for those files and not for JQuery. DW still let's me know that the file is remote and cannot be altered, but I get nothing for the other remote files.
What gives?

I was able to get it working after some scrambling, reading, and random attempts.
Turns out I was getting in my own way.
Because of the tutorial I was learning react from, I had assumed I was required to always create a react object and react-dom object.
After removing those two declarations from my js file, I was able to then see the expected results in my browser.
The only thing I can think of as to why those declarations would cause an issue is either because one of the files I import already does so (which has to happen as I don't declare the "React" or "React-dom" instances anymore but am still able to use them) or it is no longer required explicitly. The tutorial I went through was a bit dated.
I'm gonna have so much fun with this!

Unable to have access to FTP to install a slider module, use external source?

Lets say my site is: example.com
I am unable to get access to edit css files and add additional files.
Lets say I install a module on exampleTWO.com...is it possible to use that site's slider for example.com?

Yes, you can link to external resources. I've seen this done most commonly with JQuery, but the same rules apply to other resources. See this link here for more info: http://encosia.com/3-reasons-why-you-should-let-google-host-jquery-for-you/
All you need to do is rather than have something like:
<script type="text/javascript" src="/js/sliderModule.js"></script>
You include the entire external address like so:
<script src="http://exampleTWO.com/js/sliderModule.js" ></script>
As far as CSS is concerned, I believe it will work the same way. I have never actually tested this though, so someone feel free to correct me if I am wrong in that assumption. If you cannot link to external CSS files, then simply include the CSS you'd like in the HTML between <style> tags.

CDN / and or Hosting js and css files on a server

so id like to link a refernce to a couple js files if possible, but im not sure i could go about doing this so i can use it
<script type=text/javascript src=http://mylinkedjs></script>
and call i from my jquery.
Anyone know how this is possible?

Let me try to rephrase your question.
I want to include some JavaScript files from another server on my page, and call functions from those files in my own jQuery code. Is this possible?
That’s certainly possible. Once you’ve included a JavaScript file on your web page (like you did in the question), the global variables it creates are accessible to any other JavaScript running on that page, regardless of which server the JavaScript file was loaded from.
This is often how jQuery itself is included on pages: by linking to a copy of jQuery on a big CDN, e.g.
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js"></script>
See http://docs.jquery.com/Downloading_jQuery#CDN_Hosted_jQuery

<script type="text/javascript" src="http://wherever.com/linked.js">

Use wildcard in src attribute of <script> tag?

Ok, stupid question and I don't think it's possible but, I have this markup at the top of my .aspx page...
<%--Third Party Libraries, Plugins, Extensions --%>
<script src="Libraries/Raphael/Raphael.js" type="text/javascript"></script>
<script src="AutoComplete/jquery.autocomplete.js" type="text/javascript"></script>
<script src="Libraries/jQuery/1.4.2/jquery.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.core.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.widget.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.mouse.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.draggable.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.droppable.js" type="text/javascript"></script>
Wouldn't it be nice if I could replace that with this...
<%--Third Party Libraries, Plugins, Extensions --%>
<script src="Libraries/Raphael/Raphael.js" type="text/javascript"></script>
<script src="AutoComplete/jquery.autocomplete.js" type="text/javascript"></script>
<script src="Libraries/jQuery/1.4.2/jquery.js" type="text/javascript"></script>
<script src="Libraries/jQuery/UI/1.8.4/jquery.ui.*.js" type="text/javascript"></script>
ie use the * as wildcard.
Obviously as this is JS I could just throw all those scripts into one big script and load that but I don't really fancy doing that.
Anyone else have a technique for tidying up masses of script refs? Or do we just live with it?

As far as I know this is not possible, simply because, the browser would need to know exactly what files to request.
The browser would essentially have to brute force your server with requests hoping to get lucky.
I'd suggest using Google's closure compiler to merge all similar, if not all, javascript files into a single file. It will be slightly large, but would cut down on http request.
With some profiling you could find a balance between which files are needed most commonly and speed.
UPDATE (from comments)
I'm generally reluctant to offer adding a new javascript library to solve the issue of too many javascript libraries :) Plus this just seemed like the more straight forward solution. Current we use the Google closure API to compress and merge all our javascript and CSS and build time with ANT. Works a charm. This can also be done to some extent direct with apache2 virtual host/htaccess (see html5boilerplate.com) for examples and limitations

Nope, not in the way you're thinking of. You could do something that's similar if you're using JavaScript loaders (e.g. RequireJS or LabJS), since you can then condense each file into an array and loop through them, or, if you're feeling ambitious cook up some protocol between the front and back ends to support this.
Nonetheless, this is not recommended as it's not easy to maintain. If your problem with combining the files into a single one is with the effort, then JS minifiers (e.g. UglifyJS or Closure Compiler) may solve your problem.

Actually, as somebody else may have mentioned, you could add your own script file in there and do something like add the paths to an array, loop through it calling getScript for each item.
$.getScript('ajax/test.js', function() {
alert('Load was performed.');
});

ie use the * as wildcard.
No. Well, not unless you want to configure your server to pass a URL which includes a * character through a script that resolves it and bundles up all the JS on the fly.
Obviously as this is JS I could just throw all those scripts into one big script and load that but I don't really fancy doing that.
It's a good solution. Generally you would want to do this as part of a build script for the site, and throw in a call to a minifier at the same time.

I would omit type="text/javascript"
The "type" attribute is required in HTML 4, but optional in HTML5.
But I still think that merging src is impossible (as of HTML5 and CSS3)

You could just copy the contents of all the jquery.ui.* files into one file. As an added bonus, your pages would load slightly faster.