Use a different folder for assets - ruby-on-rails

For a Rails application I am making I want to be able to switch 'themes' using a configuration file. The theme does not need to switch dynamically (while running, but will be known when the application starts).
I moved my stylesheets directory out of my assets directory, to a folder called : /app/themes/[themename]/assets/stylesheets.
The idea is to have multiple folders in the /app/themes directory, which can be used by the application.
REMARK: I didn't move my javascripts folder from the assets folder, because I still want to use that globally.
In my layout I use the following code, to load controller specific stylesheets:
<%= stylesheet_link_tag "#{controller_name}" if MyApp::Application.assets.find_asset("#{controller_name}") %>
Of course, my application no longer knows where my assets are and it serves me a page, where the assets are not loading (because of the if check mentioned above).
I added the following code to my config/initializers/assets.rb to make sure it also loads the assets from the theme directory:
Dir.glob("#{Rails.root}/app/themes/#{Settings.site.theme}/assets/**/").each do |path|
Rails.application.config.assets.paths << path
end
Settings.site.theme is a string value which is filled correctly and now the stylesheets actually load on the website. So YAY!
But here is the thing, the minute I change the config.assets.compile to false, it all fails (so on test and production).
MyApp::Application.assets.find_asset("#{controller_name}") is throwing the exception undefined methodfind_asset' for nil:NilClass`.
I am on Rails 5.0.0.1.
Anyone got an idea how to fix this?

I think a simpler way would be to namespace the themes under the stylesheets. That is, have a folder structure like this:
- app
- assets
- stylesheets
- theme-blue
- application.scss
- theme-red
- application.scss
- javascripts
- application.js
And then, in your layout file, you just point the stylesheet_link_tag to theme-blue/application, like this:
<%= stylesheet_link_tag "theme-blue/application" %>
Another way to do this is have multiple layouts, one for theme-blue and another one for theme-red. In the controller, do
class BlueController < ApplicationController
layout "theme_blue"
end
And the file app/views/layouts/theme_blue.html.erb will require the right css file.
You might need to add the scss files to config/assets.rb, but Rails will tell you if you need that.

Related

Why rails loads all css files even when the page does not need that particular stylesheet?

New to Rails (Have used it for 3 weeks). I have several views and their corresponding scss file.
For example,
Views
view1.html.erb
view2.html.erb
view3.html.erb
Stylesheet
view1.scss
view2.scss
view3.scss
When I load view1.html inside <head> of the page all three stylesheet file are been loaded (I actually do now need view2.css and view3.css at this moment).
Is there a reason behind it? Why not just load the static file the current page need? For example, only load view1.css in page view1.html.
I do know in production environment all these will be combined into one single file. Is that because all these static assets will be cached by the browser so load a single file at the first time make the subsequent visit much faster?
The reason I ask this question is because I would like only include controller specific stylesheets in the page. I have tried code below but which cause non ppreprocess error.
<%= javascript_include_tag params[:controller] %>
<%= stylesheet_link_tag params[:controller] %>
I am still reading the doc at link below,
http://guides.rubyonrails.org/asset_pipeline.html#precompiling-assets
Thanks for your time viewing the question.
You can try achieve that in this way,
If you generate a controller named Userscontroller
Rails adds new files at app/assets/javascripts/users.js.coffee and another at app/assets/stylesheets/users.css.scss.
You should put any JavaScript or CSS unique to a controller inside their respective asset files, as these files can then be loaded just for these controllers with lines such as
<%= javascript_include_tag params[:controller] %>
or
<%= stylesheet_link_tag params[:controller] %>
First, disable the default loading of all stylesheets by removing any extra requires in the application.css manifest.
*= require_tree .
Remove this line or change to,
* require_tree . // removed '='
Tell Rails to compile our controller assets
By default, the asset pipeline only compiles application.js/.css and any files they require. Because we removed the require_tree . directive, we need to tell Rails about our controller-specific assets or they won’t get compiled.
Create a new initializer file called config/initializers/assets.rb and add the following (replacing the controller names with your own):
%w( controller_one controller_two controller_three ).each do |controller|
Rails.application.config.assets.precompile += ["#{controller}.js.coffee", "#{controller}.css.scss"]
end
Note: You can rename the css.scss to css also.
Check this link for details
Explicitly declare all controllers make me feel bad, therefore, we replace #Sravan 's solution to the code below,
Rails.application.config.assets.precompile << /(^[^_\/]|\/[^_])[^\/]*$/
Rails.application.config.assets.precompile += ["*.js.es6", "*.scss"]

Adding page-specific CSS to Rails Asset Pipeline

This is a question that several people have asked before, but none of the questions were quite asked or answered in a way that I found helpful, so I'm writing the question and answer that I would have found helpful.
I have a Rails 3.1+ app using the asset pipeline. There's one specific action that I want to have use different CSS. (In my specific case, I have a page that is intended to be printed, so it truly needs completely different CSS and does not need any Javascript.) Currently, I have only one application-specific CSS file. How do I add the new CSS file and direct the asset pipeline to use my file?
For example, right now, my app/assets looks like
app/assets
/javascript
application.js
custom.js.coffee
/css
application.css
custom.css.scss
I want to add a print.css file that is used by the view of a specific action. This view will not use the application.css file. How do I add print.css?
I found this blog post to be very helpful: http://blog.seancarpenter.net/2012/11/05/page-specific-javascript-with-the-asset-pipeline/. My answer paraphrases what this blogger already wrote and fills in a few missing details.
First, it's important that you've read and understood the Rails Guide to the Asset Pipeline. Unfortunately, this guide doesn't clearly explain how to add action-specific assets, but it does cover some concepts you need to know. Made sure you understand these ideas:
That the asset pipeline compiles Javascript, CSS, and other assets so that Rails servers can cache assets for better performance.
That manifest files use commands like require, require_tree, and require_self to indicate which files are compiled together.
That in order for the asset pipeline to work properly in production, you need to manually run rake assets:precompile to produce the compiled, minified assets in the public directory.
These ideas are the minimum "need-to-know" pieces of information about the asset pipeline. If you don't already understand these ideas, you don't have an "expert or enthusiast" level of knowledge about the pipeline, and unfortunately, SO isn't the right place to learn this stuff. Fortunately, the the Rails Guide to the Asset Pipeline is a short 15-minute read and can get you up to speed quickly if you need it.
Second, these are the changes you need to make in order to ensure that the asset pipeline correctly sees and handles your new print.css file.
Follow these steps:
Add your print.css file to app/assets/css.
You'll need to create a manifest file that will show Rails where to find print.css. You need to do this, even though you only have a single CSS file you're adding. This is an easy step:
Add a file called print.js to app/assets/javascript.
Add this line to print.js:
//= require print
This will be the only line in the entire print.js file. If I understand correctly, Rails expects manifest files to have the file extension .js, which is why we aren't using print.css as the manifest file.
We now need to instruct Rails to find and use the print.js manifest. Add the following line in your config/application.rb file:
config.assets.precompile += %w( print.js )
We're almost finished! However, the already-present application.js manifest includes the line //= require_tree . which means that it will include your print.css file. This will cause your print.css styling to affect your entire site, not just the single view. There are two ways of dealing with this:
If application.js and print.js do not share any assets, you can use the stub command in your application.js to exclude the assets used in print.js. What this does is instruct application.js to remove any of the assets that print.js references from its own list of referenced files. Our modified application.js looks like:
(snip...)
require_tree .
stub print
See this answer for more information.
If your print.js and application.js files share some assets, you'll need to move all of the assets used by application.js into subdirectories. I didn't do this myself, so I'm not the most help in this area. Look at this answer for instructions.
Now we have included print.css in the asset pipeline. We now need to direct Rails to use print.css in your specific view.
Let's say your action is in the reports controller, and that the action is named print_reports. This means we have a reports_controller.rb file and a print_reports.html.erb (or .haml) file. We need to make several changes to these files.
To start, add a new layout in app/views/layouts. Perhaps call it print.html.erb. We'll use this new layout for your print_reports.html.erb file. Set it up as you desire. For a page intended to be printed, this will likely be very simple, such as
<html>
<head>
<title="Print">
</head>
<body>
<%= yield %>
</body>
</html>
Using a separate layout the disadvantage that it's difficult to keep this layout and the layout used by the rest of the application in sync, but if you are using separate CSS files for the action, it's unlikely that you want the layout to be the same anyway.
Add a stylesheet_link_tag in the layout's header pointing to your print.css:
<html>
<head>
<title="Print"/>
<%= stylesheet_link_tag "print" %>
</head>
<body>
<%= yield %>
</body>
</html>
In the controller, we'll tell Rails to use our new layout for the action. Add the line layout 'print', only: [:print_reports] to your controller:
class reports_controller < ApplicationController
layout 'print', only: [:print_reports]
#snip
See this question for more information and a few different approaches.
At this point, when you run the app, your print_reports action should be using print.css correctly!
Remember to run rake assets:precompile before deploying on the server.
Official Solution
It is documented in the official Rails Guides here: http://guides.rubyonrails.org/asset_pipeline.html#controller-specific-assets
Actually you can leave out the require_tree directive (located in application.css and application.js) then use this in your template:
For controller specific JavaScript:
<%= javascript_include_tag params[:controller] %>
For controller specific CSS:
<%= stylesheet_link_tag params[:controller] %>
All of you are putting very complicated answers.
1 Go to app/assets/stylesheets
2.Make a file with the extension .css
3.Go to config/initializers/assets.rb
4.Put this line of of code Rails.application.config.assets.precompile += %w( file.css )
5.Replace file.css with the file you created
6.Go to your html.erb file
7.Type this in the <head>, <%= stylesheet_link_tag "file" %>
8.Replace file with the filename(no extension in the name)
Good Job you linked the file!
There's one specific action that I want to have use different CSS.
Here's an alternative way to accomplish what you're looking for:
Add the controller name and action name to the app body in your /views/layouts/application.html.rb:
<body class="<%= controller_name %>-<%= action_name %>">
<%= yield %>
</body>
Then in your .scss file:
.controller_name-action_name {
// your css goes here
}
So if your controller was static_pages and your action was home:
.static_pages-home {
// your css goes here
}
Tada! Your css only appears for that specific action.
In your layout
<head>
// ...
<%= yield :stylesheets %>
</head>
In your view
<%= provide :stylesheets do %>
// your page-specific css
<% end %>

Rails - Assets loaded on all pages

So I'm kinda lost here. All my CSS/SCSS files are loaded everywhere on my app. But I have two different design (front and back) that I want to separate. How can I achieve that ?
Plus it's kinda useless that all js/css are loaded, even where they are not used. How can I control that ?
What you're wanting to do is control your layouts.
As your question is currently it's too broad for someone to give you a decent specific answer, it's like saying 'tell me about astrophysics, I don't understand how to launch a rocket right now'.
I would suggest to start with the rails guides relating to layouts and then come back with a more specific question once you have a better understanding.
http://guides.rubyonrails.org/layouts_and_rendering.html
There is also a great 11 minute video on RailsCasts which will help you understand and control the assets pipeline: http://railscasts.com/episodes/279-understanding-the-asset-pipeline
Where you are heading is say your app was about managing projects.
Make a copy of the application.css file called say project-manifest.css and use the same structure as that application.css for loading just the stylesheets you want.
Make a copy of views/layouts/application.html.erb to say projects-layout.html.erb
In the new projecs-layout file, update the reference to the css to point to project-manifest.css
Point your controller code to use your new layout
say you have:
# app/controllers/ProjectsController.rb
def show
# code here
# rails does a default render layout: 'application', its overwritten by adding an explict render
render layout: 'project-layout'
end
In your application.js and application.css there is a directive by default: require_tree. It will load all your js and css files to be precompiled later. This is done to make the clients to download the assets packet only once (as it will be cached by the browser) and make the app faster.
If you want to load specific javascript or stylesheet files for each controller, remove the require_tree directive and include them in their respective controller:
<%= javascript_include_tag params[:controller] %> or <%= stylesheet_link_tag params[:controller] %>
Check this out: http://guides.rubyonrails.org/asset_pipeline.html#controller-specific-assets

Rails asset pipleline: compile to multiple stylesheets

Due to a specific setup, I would like to split the compiled stylesheets in two files. This is because (a part of) the CSS is needed for a Java application which can parse the CSS, but it is a bit buggy and can't handle some css-(hack)-syntax. Because I am unable to modify this Java application, I want to feed it only the CSS which it needs and of which I can make sure it is correct.
So, normally the assets pipeline would produce just one '/assets/application-[..].css' file. It would to let it also generate '/assets/custom-[..].css', based on a file selection I make. This still can be pre-compiled.
Is there a way to do this? Although I understand this is not the ideal setup..
To tell rails about additional files you wish to have precompiled, you can add them to the config.assets.precompile setting.
config.assets.precompile += ["other_application.css"]
You only see application.css in your HTML because that's the only file you're including
<%= stylesheet_link_tag "application" %>
If you have some custom.css.scss in your apps/assets/stylesheets directory, it will be compiled just like application.css.
For example, I might have
- _common.css.scss
- application.css.erb.scss
- other_application.css.erb.scss
in app/assets/stylesheets. In the top of the non-partial files I will put
#import "common";
to include _common.css.scss. I can now reference either stylesheet independent of one another in a layout.
<%= stylesheet_link_tag "application" %>
# or
<%= stylesheet_link_tag "other_application" %>

How do I use CSS with a ruby on rails application?

How do I use CSS with RoR? When I link externally, I'm never able to see the files. I cp'd the .css file to every folder I could think of...views, controller, template, and nothing seems to work.
What do I need to do to enable external CSS files with a rails application? I'm new to rails, so forgive me if this is basic.
Put the CSS files in public/stylesheets and then use:
<%= stylesheet_link_tag "filename" %>
to link to the stylesheet in your layouts or erb files in your views.
Similarly you put images in public/images and javascript files in public/javascripts.
If you are using rails > 3 version, then there is a concept called asset pipeline. You could add your CSS to
app/assets/stylesheets
then it will automatically be picked up by the app. (this is useful as rails will automatically compress the CSS files)
read more here about the asset pipeline
Use the rails style sheet tag to link your main.css like this
<%= stylesheet_link_tag "main" %>
Go to
config/initializers/assets.rb
Once inside the assets.rb add the following code snippet just below the Rails.application.config.assets.version = '1.0'
Rails.application.config.assets.version = '1.0'
Rails.application.config.assets.precompile += %w( main.css )
Restart your server.
I did the following...
place your css file in the app/assets/stylesheets folder.
Add the stylesheet link <%= stylesheet_link_tag "filename" %> in your default layouts file (most likely application.html.erb)
I recommend this over using your public folder. You can also reference the stylesheet inline, such as in your index page.
The original post might have been true back in 2009, but now it is actually incorrect now, and no linking is even required for the stylesheet as I see mentioned in some of the other responses. Rails will now do this for you by default.
Place any new sheet .css (or other) in app/assets/stylesheets
Test your server with rails-root/scripts/rails server and you'll see the link is added by rails itself.
You can test this with a path in your browser like testserverpath:3000/assets/filename_to_test.css?body=1
To add to the above, the most obvious place to add stylesheet_link_tag is in your global application layout - application.html.erb.
With Rails 6.0.0, create your "stylesheet.css" stylesheet at app/assets/stylesheets.
Have you tried putting it in your public folder? Whenever I have images or the like that I need to reference externally, I put it all there.

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