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What are the options for managing controller-specific javascript in symfony2?

I understand the general concept of assetic, which makes sense for site-wide script resources, but what about the javascript that is specific to one page or controller? How do you structure those, where would one keep them, and then how would they be added to the templates?

Typically what I do is create a 'controllers' folder inside my Resources\public\js folder and then create a file with the same name as the controller it's going to be used in. Then all you need to do in your twig template is include the file using the assetic <% javascripts %><% endjavascripts %> tag.

Is it possible to use Mojolicious tag helpers in external JS files?

I am currently working on cleaning up a little web app I've written in Mojolicious. As part of that cleanup I am separating out my javascript into the public directory from my html.ep files.
The problem I have though is I don't seem to be able to reference tag helpers any more, like 'url_for' or even referencing values in the stash such as '<% $stashvalue %>'.
Any idea's on how or if I can do this is very much appreciated.
cheers.

The stuff in the public directory is served statically, optimally by your webserver, not by Mojolicious or Plack, so that file does not get processed by Mojolicious, thus <% $stashvalue %> not meaning anything.
A solution would be to embed those parts of javascript that need to access server side variables in the mojo templates - rather ugly, but less code to be written.
Another one would be to make an ajax call from your javascript files, when they are loaded, and get the values sent by the server - more elegant, but more code to be written.
Another one that I can think of, would be to move those javascript files under a folder that gets processed by Mojolicious and include them parameterized - in your html.ep file that needs that js file, do :
<script type="text/javascript" src="http://example.com/url/served/by/mojo/?param1=<% $stashvalue %>&param2=<% $stashvalue2 %>"></script>
And, in the controller that responds to /url/served/by/mojo/, render that js file, with the params replaced by the ones from the query. As an alternative, you could store/receive those params also on the session
As usually in Perl, there is more than one way to do it.

What I typically do is encapsulate most of my javascript in function calls or objects in pure javascript files. Then in my templates I include those pure javascript files and use the api that I built in those files from the template, interpolating the server-side variables into the arguments of the functions. You can peruse the code for Galileo to see several examples.
For example, see how this template passes stash values to this pure javascript file's functionality.

How do you put ruby inside a javascript function, google maps?

I have a ruby on rails app that has a google map with a marker on it that when you click it it opens an info window using javascript. I want to put ruby var in this javascript fn that displays info from the database in the window.
So when the user clicks the marker they get dynamic info from database not just generic text from js fn.
If anyone has done this before I'd appreciate if you could tell me how you did it , thanks

You can put your javascript directly on your html.erb file using tag and run embedded ruby code within the javascript. Remember to escape_javascript because sometimes your variables will mess up your script by some special characters like apostrophes.
<script>
alert(<%= escape_javascript #variable %>);
</script>

Edward's solution of processing your Javascript files with erb will work (though you will have to remember to add .erb to the end of your JS file so that ERB knows to process it... ie maps.js.erb).
The thing is, this is contrary to the philosophy of the asset pipeline as I understand it. Rails purposely concatenates all your Javascript into one file to save on the overhead of HTTP requests. More importantly, however, browsers cache this file so they do not need to refetch it on every request. If you have a variable that changes the JS file depending on the request made, Rails needs to reprocess the JS file for every request, which is expensive. (Note that the same concept applies to CSS).
The best solution I have found is to put the variable value in the page somehow, since this is one file that needs to be dynamically processed on every request. Usually I see people putting them in hidden forms, as such:
<%= content_tag :input, nil, :type => 'hidden', :id => "map-name-field", :'data-name' => #map.name %>
One approach I have also used is to attach it to an element on the page which is unique to that page, such as a name or title:
<%= content_tag :h2, #map.name, :id => "map-name", :'data-name' => #map.name %>
Once it's on the page, you can fetch from within your JS function (but the key here is that the fetcher function is the same for all isntances of your map, and thus does not need to change or reprocess the JS file):
// Assuming jQuery
// For the hidden input approach:
var mapName = $('#map-name-field').value
// or for the data-attribute approach:
var mapName = $('#map-name').attr('data-name')

jquery/javascript in rails 3

I was under the impression that you could put javascript in a view template in Rails 3. For example, if I had this html in views/public/home.html.erb
<div id="block">click</div>
then in views/public/home.js.erb, I thought I could put the following javascript, and then click on html to trigger the javascript. However, when I tested it, I got no results. But if I put the javascript in assets/javascript/application.js, then everything worked fine...Shouldn't it also work if it was in a js template with the same name as the html view?
$(document).ready(function(){
test();
});
function test() {
$("#block").click(function() {
$('#block').hide();
});
}

Ummm. no. It just doesn't work that way. Only one of views/public/home.* will be rendered, depending on the responds type.

Javascript shouldn't be added as a view file (bla.js.erb). They must be put in assets/javascripts or at least in lib or vendor directory.
You must also require them in your application.js file, if you already don't use require_tree.
In this way you won't need to reference the javascript in any way in your view (the application.js will include it for you). Otherwise, you need to specify a layout to insert javascript files in block, because views are rendered after tag.
There are a lot of reason not to put javascript directly in html (except for tests obviusly), read the rails asset pipeline for more information.
When you create a view with a different extension from html.erb that will be used only if your url specify a format with that extension, for example mywebsite/users.json will return eventually a index.json.erb.
For AJAX you would like to return a JSON object, not javascript which is definitely not a correct approach. Remember that you are using a framework and you should follow it's guidelines. If you want to live it's rails, it will be hard to work with it.

You can use javascript_include_tag
If you have the js files source1.js, source2.js in public/javascript then you can include them using
javascript_include_tag 'source1', 'source2'

Executing groovy statements in JavaScript sources in Grails

There are essentially 2 places to define JavaScript functions in Grails, directly in a element on the GSP, and within a separate javascript source file under /web-app/js (for example, application.js). We have defined a commonly reused javascript function within application.js, but we also need to be able to generate parts of the function dynamically using groovy code. Unfortunately, ${some groovy code} does not appear to be processed within separate javascript source files.
Is the only way to do this by defining the javascript function within a script tag on a GSP page, or is there a more general solution? Obviously we could define the javascript function in a script tag within a template GSP file which would be reused, but there is a lot of push to keep our javascript functions defined all together in one place (i.e. the external javascript source file). This has performance benefits as well (the javascript source files are usually just downloaded once by each client's browser, instead of reloading the same javascript functions within the source of every html page they visit). I have toyed around with the idea of breaking the function up into static and dynamic pieces, putting the static ones in the external source and putting the dynamic ones in the template GSP, then gluing them together, but this seems like an unnecessary hack.
Any ideas?
(edit: It may sound like the idea of dynamically generating parts of a JavaScript function, which is then downloaded once and used over and over again by the client, would be a bad idea. However, the piece which is "dynamic" only changes perhaps once a week or month, and then only very slightly. Mostly we just want this piece generated off the database, even if only once, instead of hard coded.)

An easy solution to keep your JavaScript unobtrusive is to create a JavaScriptController and map its actions "/js/*" by adding this to your UrlMappings.groovy file:
"/js/$action"{
controller = "javascript"
}
then just create an action for each dynamic JS file you want, include in in your layout <HEAD>, and presto, you've got a JS file that you can insert Grails snippets into! :)
Note: I've found that there's currently a bug in Grails that doesn't map file extensions to content-types properly, so you'll need to include <%# page contentType="text/javascript; UTF-8" %> at the top of your view files.

This is a great solution. I would like to offer a suggestion to use somthing other then a mapping of "/js/$action" because this is no longer going to allow you to access you javascript files in /web-app/js/. All your javascript files would have to be moved to a the directory your controller would point to.
I would use something like
"/dynjs/$action"
This way you still can point to files in the /web-app/js/ files with out conflict and enjoy the benifits of gsp tags in javascript files
Please correct me if I'm wrong.

Or this... have a tag/service/dynamic method that lets tags write out their JS+CSS+whatever else, to a "cache" which is used to build the JS+CSS resources by a different controller.
Full concept here: [http://www.anyware.co.uk/2005/2009/01/19/an-idea-to-give-grails-tags-esp/][1]

If you want to use models created by the controller (that rendered HTML page which reference the Javascript in which you intend to use groovy code) in the Javascript code, then you can use this technique:
This technique does not need to change URL mappings and does not require you to create extra controller.
In your view GSP add javascript as follows:
<script type="text/javascript">
<g:render template="/javascript/yourJavascriptFile"/>
</script>
In views folder create a "javascript" folder. And create a file named:
_yourJavascriptFile.gsp
You can not only use all the GSP code in your _yourJavascriptFile.gsp file, but you can also use all the models created in your controller (that is rendering the view).
NOTE: There is nothing special about javascript folder. You can name it anything you want OR use an existing view folder. This is just a matter of organizing and identifying your HTML spitting GSP from Javascript spitting GSPs. Alternatively, you can use some naming conventions like: _something.js.gsp etc.

Name your scripts like this
/wherever/the/js/files/are/thescript.js.gsp
The gsp code inside will be rendered correctly by grails. This works, but I have no idea if it's considered a Good Idea or not.

There is another way - pass in the generated code into a function that expects closures. Those closures is generated by the program of course. The generated code is of course inlined/script-tagged in the gsp page.
it may or may not work depending on the nature of the code being generated. But i suspect it will work, and if it doesnt, minor tweaking to the coding style of your javascript will definitely make it work. Though, if these 'generated' code doesnt change much, this quite overkill imo.