Rails 3: Separate javascripts for each action? - javascript

I have an app where I keep track of different "Games". In the "show"-view, I would like to show the game information plus a select, which I can use to quick-jump to a game.
The quick-jump feature would obviously be some javascript but here's my problem: After some reading, I still don't get how I can have a separate javascript file for each action of a controller. I could add the code to the application.js but I think that would blow-up that file unnecessarily. Any link to a good basic guide for the interaction between Rails 3 and Javascript would also help very much. Thanks!

The answer to the following question spells this out a bit more specifically and with a helper method to make it a bit more elegant. Same idea though:
Rails 3.1 asset pipeline: how to load controller-specific scripts?

Just introduce separate javascript files per controller+action basis (e.g. CONTROLLERNAME_ACTIONNAME.js, replacing CONTROLLERNAME and ACTIONNAME with your actual names ;) ) and include them in your views with javascript_include_tag(CONTROLLERNAME_ACTIONNAME.js).


Whats the best way to manage JavaScript with Ruby on Rails 6?

I'm giving a try to RoR 6 (I'm coming from MEAN and I've not touched RoR from version 3) and I'm finding some troubles to find the best way to manage JavaScript code. Maybe because of my background.
I've read a lot about the topic (including official guides https://guides.rubyonrails.org/working_with_javascript_in_rails.html) but It seems official documentation is out of date.
According to documentation, when you generate a controller from cli it should create a .js file for that controller but it doesn't occur. Besides, right now Webpack has been added to RoR 6 and JavaScript is no longer managed by Asset Pipeline (Am I right?) but there's not any reference to this matter.
I want to find a way to write code JS for every view and keep that code isolated from the rest.
Where should I put all the JS code?
How can I get isolation for the JS code of every view?
I've added jQuery to the project due to Bootstrap (by using Yarn) and to Webpack this way but $ or jQuery is undefined:
const { environment } = require('#rails/webpacker')
const webpack = require("webpack")
environment.plugins.append("Provide", new webpack.ProvidePlugin({
$: 'jquery',
jQuery: 'jquery',
Popper: ['popper.js', 'default']
module.exports = environment
I'd appreciate some help.
I found what I was looking for --> https://stimulusjs.org
Stimulusjs, created by Basecamp, adds a JS layer to every HTML view and let us to keep order and clarity when writing JS code. It connects the JS file with the DOM and nothing more. Enough to add some JS to improve functionality.
It pairs perfectly with Turbolinks and is ready to be used with Webpack. Besides, it can be learned in 10 minutes (no more). Installation is also absurdly easy.
Anyway, if you need to get some knowledge about RoR and Webpack/Webpacker, you can visit these links:
And finally, if you don't wanna use a JS framework like Stimulus for managing JS code under RoR, you can always try these gems for specific page JS:
Paloma gem: https://github.com/gnclmorais/paloma (not checked)
Pagescript gem: https://github.com/maxcal/pagescript (not checked)
The change to Webpack is very new and the documentation has not quite caught up.
Generating asset files when running the generator was only done with the old assets pipeline and even then was a not really good idea. It relied on Sprockets special require_tree directive that would slurp up all the files in the directory and add them to the manifest. In alphabetical order, so you had no control over the order of execution.
It also fooled beginners into thinking that the js they put into users.js was only executed in their users controller when in fact it was all just slurped up into a single manifest.
With Webpack you explicitly import assets.
Where should I put all the JS code?
You're encouraged to place your actual application logic in a relevant structure within app/javascript.
How can I get isolation for the JS code of every view?
While you can use javascript_pack_tag in the view itself to require specific files this is not really a good idiom as it creates unnecessary HTTP requests and logic that is hard to follow.
If you want to ensure that code is executed when a particular view loads you can add data attributes to the body tag and create special events:
# app/layouts/application.html.erb
<body data-action="<%= action_name >" data-controller="<%= controller_name %>">
// fired when turbolinks changes pages.
$(document).on('turbolinks:load', ()=>{
let data = $(body).data();
// replace myns with whatever you want
$(this).trigger(`myns:${data.controller}`, data)
.trigger(`myns:${data.controller}#${data.action}`, data)
.trigger(`myns:#${data.action}`, data)
Then you can wrap functionality that should happen when a special page loads by listening for your custom events.
$(document).on('myns:users#show', ()=>{
console.log("We are on users#show");

How to structure app with Angular JS

I am trying to learn Angular JS and use it in my web app project and am looking for some guidance as well as answers to specific angular js questions. Tech stack I am using is MySQL db, Java w/ Spring Framework, HTML/CSS/Bootstrap/JS, etc..
The purpose of the app is basically a "social media craigslist" where it will have:
1. User accounts
2. Ability to create a "newsfeed-esque" post (one "view")
3. Ability to create a sale post (separate "view")
4. A view for an "inventory"
5. A view for a "wishlist"
(note: Items 2-5 are accessed via a nav bar of sorts that sits on the left side of my page and the idea was to have the main section of the page switch the content based on what nav item you clicked.. more later..)
What I was doing was writing a bunch of Javscript code to make calls to my web services (grabbing static content to populate drop downs, sending user login info for logging in, etc..) and the < script > tags were growing and all of this was living in my index.html page and I thought it might make more sense to use something like Angular JS and structure it a bit differently and "modularize" the code so it wasn't a giant mess in index page. I was also doing some manual .hide() and .show() JS stuff so I thought that it also might make more sense to switch out the content using something like AngularJS instead of having maximum ONE .show() active at once and then having to do as many .hide()'s as I would need to, to manually switch out the content. This is sounding like a SPA (single page app) right?
I have researched AngularJS StackOverflow posts and looked at w3schools and other helpful websites but am having trouble with how to structure this and use best practices not only with code efforts but organizational as well.
1) Am I correct in thinking Angular would make the hide and show of content easier?
2) I would like to make each "feature" of my website have its own controller and have Controller1.js, Controller2.js, etc.. but do I need to have a
var app = angular.module('myApp', []); ...
line at the top of each controller or do I need something like a main controller with that in there only once and then a call to each controller from a main controller? Or is this not even how I should go about it? Thought process was again to modularize and avoid having one giant beastly file with all my JS logic in it.
3) I assume that I need to use the ng-route stuff (is this correct?) in order to do that hide and show of html content? (items 2-5 listed above) But in what file should that live? a javascript controller file? index.html? other?
4) I read you can only have one ng-view per application. Does that mean that you can only switch/change the content for ONE < div > / section of your web app, OR can you have multiple different divs being changed?
5) fyi - my current file structure is pretty much this.. is this how it should be?
-Java Resources (java code)
-css (folder)
-js (folder with js files - controllers)
-lib (folder)
-views (folder)
A lot of my questions are just because I am new to AngularJS and not seasoned in JS itself so am trying to better understand. Thanks for any and all help in advance.
First of all, if you want to use multiple views per app then you should use angular-ui-router module instead of angular-route module.
Now, we come to the file handling. So, for that you can make as much file as you can to define controllers, config, services and factories for the app. There are three ways of doing this.
The first one is putting var app = angular.module("MyApp",[]); in first file and defining controllers and services like app.controller('ctrl', ControllerFunction) in each of the other files below the first one. But, personally i don't prefer to use this way as you are exposing your app as a global variable here.
The second way is to create a main module in first file using angular.module('MyApp',[]) and in other files you can get it and define controllers using angular.module('MyApp').controller('ctrl', ControllerFunction). This is the safer way than the previous one.
The third way is to create a different module in each of the files and using all the modules in a single main module as dependencies. Like below
in one file
in another file
and in the main file, the main module, which is to be bootstraped
This is the safest way to define services in different files. I personally advise this way of using multiple js files in single app. Because here you care not exposing a global variable or a single module, so anyone cannot inject some code using console easily.

Best way to use C#-Ressources (ResX Files) in Typescript?

our current project is in ASP.Net MVC with Razor.
We use ResX Files for a few thousend translations.
In C# and Asp.net Razor this is pretty easy with HTML:
Now when I wrote JavaScript I normaly did this within the cshtml files with razor like this:
Which works but seems a bit ugly...
A few weeks ago we starded with Typescript, and, of course excluding (nearly) all javascript code to ts-files.
The only solution we found here, to get the ressources from C# to Typescript is through a "hack":
We made a ressources.cshtml file in which we just include javascript variables:
var ressourceTest = "#Ressource.Local.Test";
We load this ressource.cshtml at first in our _layout.cshtml.
Additional, we have a self need a selfmade declarion for this variable to jump from javascript to typescript in our projectDeclarions.d.ts:
var ressourceTest:string;
And now we can use the ressource in our typescript file test.ts:
As you can see it is a working "hack" or "workaround" but it seems to likly kill us for a few thousend ressources... It's handmade, the maintain duration and work is high...
Any better ideas?
I have seen a few good ideas around this.
You could supply an JSON endpoint in your MVC application to give you chunks of translations. You would decide how granular you want to make it, but you would essentially JSON serialize a translation, or set of translations and send it back. This would avoid stuffing a big view with hundreds of the things.
Another alternative is to place translations in the view to make them available, but contextually. So if you had a button that you are using to trigger some AJAX call to the server and you need to say "Update Worked" or "Update Failed" you could put the attributes inline...
<button ... data-msg-success="Saved OK" data-msg-failed="A problem occurred" />
And you could populate these attributes with your resources.

Ruby on Rails with Unobtrusive JavaScript - Managing URLs

I'm using a modular system of JavaScript files when working in Rails - basically each view will have its own module in a .js file. My issue comes when I need a dynamic, Rails generated string within my JavaScript, for example translation strings and URLs.
Translations are nicely solved using babilu but I'm still stuck on the generation of URLs. I could write something that looked at the routes in the application and generate JavaScript methods which I could pass stuff like IDs of objects.
An alternative would be to pass in the already-generated URL to any functions I was calling, which sounds messy but could be the most flexible alternative.
I don't know that there's any truly pleasing way to do this, but one possibility is to have your server-side code write a small <script> block into the page to declare some variables that your packaged Javascript can discover and use.
var pageGlobals = {
interestingURL: <% ... url %>,
I've done this to keep track of things like image subdirectories that are determined by customer "syndicate" affiliation. The Javascript code just knows that whenever it needs that for a URL, it can just go look in a global object and pick out a standardized variable.
In my experience there tend to be only a small number of such things to communicate to the canned Javascript, so the <script> block tends not to get out of hand. I've buried mine in a page template so I don't even have to think about it with new pages.
Oldish question, but here's another way. The HTML 5 spec allows for custom data- attributes.
In your view:
<button id="myButton" data-url="<%= my_resource_path %>">Click me</button>
Then in your packaged js:
var myurl = $("#myButton").data("url");
See here also.
I don't like this either. The ideal solution to me would be javascript templates. Imagine in the .js file you could do:
var users_path = '<%= users_path %>';
But that would mean the .js files would have to be regenerated in every request (well, one could use caching just like with rails html).
Anyway, what you can also do is put the dynamic stuff in data- attributes. So you can do for example
<%= select_tag :select_something, select_options, 'data-url' => users_url %>
And then read that attribute out in the javascript file. I prefer this over the solution suggested by Pointy.
Edit: Well actually someone implemented the dynamic .js file idea. Seems straight forward enough, just create a javascripts controller and link to its actions via javascript_include_tag: dynamic javascript files

How do you organize your Javascript code?

When I first started with Javascript, I usually just put whatever I needed into functions and called them when I needed them. That was then.
Now, as I am building more and more complex web applications with Javascript; taking advantage of its more responsive user interaction, I am realizing that I need to make my code more readable - not only by me, but anyone who replaces me. Besides that, I would like the reduce the moments of 'what the heck, why did I do this' when I read my own code months later (yes, I am being honest here, I do have what the heck was I thinking moments myself, although I try to avoid such cases)
A couple weeks ago, I got into Joose, and so far, it has been good, but I am wondering what the rest do to make their chunk their codes into meaningful segments and readable by the next programmer.
Besides making it readable, what are your steps in making your HTML separated from your code logic? Say you need to create dynamic table rows with data. Do you include that in your Javascript code, appending the td element to the string or do you do anything else. I am looking for real world solutions and ideas, not some theoretical ideas posed by some expert.
So, in case you didnt't understand the above, do you use OOP practices. If you don't what do you use?
For really JS-heavy applications, you should try to mimic Java.
Have as little JS in your HTML as possible (preferably - just the call to the bootstrap function)
Break the code into logical units, keep them all in separate files
Use a script to concatenate/minify the files into a single bundle which you will serve as part of your app
Use JS namespaces to avoid cluttering up the global namespace:
var myapp = {};
myapp.FirstClass = function() { ... };
myapp.FirstClass.prototype.method = function() { ... };
myapp.SecondClass = function() { ... };
Using all these techniques together will yield a very manageable project, even if you are not using any frameworks.
I use unobtrusive javascript, so, outside of the script tags I don't keep any javascript in the html.
The two are completely separated.
A javascript function will start when the DOM tree is completed, which will go through the html and add the javascript events, and whatever else needs to be changed.
In order to organize, I tend to have some javascript files that are named similar to the html pages that they use, and then for common functions I tend to group them by what they do, and pick a name that explains that.
So, for example, if I have UI functions then I may call them: myapp_ui_functions.js
I try to put the name of the application in the filename, unless there is some javascript that is common to several projects, such as strings.js.
I have (usually) one file that contains a bunch of functions and that's it. That is included in every page that uses Javascript. In the pages themselves, I'll make the calls to the functions like:
$(function() {
where delete_user() and new_user() are defined in the external file.
I too use unobtrusive Javascript, which for me means jQuery (there are other libraries that are unobtrusive).
You don't want a separate file for each page. That just means more unnecessary external HTTP requests. With one file—assuming you've cached it effectively—it'll be downloaded once and that's it (until it changes).
If I have a large amount of Javascript or the site is effectively split into multiple areas then I may split the Javascript but that's not often the case.
Also, in terms of my source code, I may have multiple JS files but I'll often end up combining them into one download for the client (to reduce HTTP requests).
More at Multiple javascript/css files: best practices? and Supercharging Javascript in PHP.
I've been rewriting a lot of my reusable code as jQuery plugins. I moved to jQuery from Prototype when I started doing ASP.NET MVC. Overtime I've migrated a lot my reusable code, or at least the ideas, from Prototype-based OO to jQuery-style plugins. Most of these are stored in their own JS files (mainly intranet apps so page load speed is pretty high anyway despite the extra requests). I suppose I could add a build step that coalesces these if I needed to.
I've also settled on a MasterPage approach that uses a ContentPlaceHolder for scripts that is right before the closing body tag. The standard jQuery/jQuery UI loads, and any other common JS goes right before the script placeholder in the MasterPage. I have tiny bit of JS at the top of the MasterPage that defines an array that holds any functions that partial views need to run on page load. These functions are run from the base document.ready() function in the MasterPage.
All of my JS is completely separate from my mark up. Some JS may exist in partial views -- these are encapsulated when the partial may be included more than once to make it specific to that instance of the view -- but generally not. Typically only included in the placeholders so that it's loaded at the bottom of the page.
Also, if you want to go OO heavy, check out mochikit: http://www.mochikit.com/
I find that developing your javascript using OO methodology is the way to go if you want it to be clean, readable and even somewhat secure. I posted the following question
Cleanest format for writing javascript objects
And got some fantastic responses on how to write my javascript code well. If you follow these basic principles you can use almost any library, such as yui, jquery and prototype, with ease.