Is it necessary to run the rake assets:precompile command? - ruby-on-rails

Is there a situation where it is not necessary to run this command? i.e. I don't have static images in the assets directory

Heroku includes asset precompilation as a step in the deploy process. As I see you're using Heroku, that means that you don't have to run rake assets:precompile before committing or pushing. Just make sure that the code that needs to be preprocessed is included in the commit that you're pushing (i.e. the files in /app/assets/(javascripts|stylesheets) etc are up to date).
If you're only deploying to Heroku and working locally in the "development" environment, then you might consider adding /public/assets to your .gitignore and deleting that folder.
See the Heroku docs on this.

Related

Do you always have to run rake assets:precompile locally?

I read the docs but can't seem to understand if you have to run rake assets:precompile locally each time you change scss file or any other assets? Isn't there an automatic way to do it? One of the things I have noticed is that I forget to run it sometimes and my heroku changes do not appear. There must be a way to set it up automatically in rails?
If I change
config.assets.compile = false
to true, will do that it? Is a disadvantage of doing that?
You don't have to precompile your assets for Heroku to serve them. Heroku will precompile your assets automatically if you have not already precompiled assets locally. Read this heroku doc regarding the asset pipeline in Rails 3 (even if you are already using Rails 4). Then read this doc regarding the asset pipeline in Rails 4 on heroku.
Pay particular attention to this part:
If a public/assets/manifest.yml is detected in your app, Heroku will
assume you are handling asset compilation yourself and will not
attempt to compile your assets. Rails 4 uses a file called
public/assets/manifest-.json instead. On both versions you
can generate this file by running $ rake assets:precompile locally and
checking the resultant files into Git.
rake assets:precompile must be run for production environment. Do not need to run the command for the development environment. The command is used to collect all files into one and so be lighter to serve in production. Under development the styles they are wanted in the assets folder. After running the command, the styles are placed in the public folder.
If you forget to run rake assets:precompile Heroku should do it automatically. One reason it may not be is if you have checked your public folder into git as then during slug compilation Heroku will assume you precompiled your assets and will not do it for you.
Setting config.assets.compile = true can slow down your application by a lot, which is why it is only used in development.

Rails assets precompile on development issue

I precompiled assets on my dev environment (by mistake!) now any changes done on js/css files are not reflecting on browsing site locally.
I removed assets folder from public directory but then no css/js was available.
How do I get rid of this?
As a temporary solution I just cloned project into new directory and it works.
The question is: why do you need asset precompilation in the development environment? It's not meant to work like this.
The asset pipeline allows working in development with the uncompressed, unminified versions of your JS files. It also reloads them each time you refresh your browser, so you can develop your application with ease.
In production, though, the asset pipeline precompiles the JS files / assets you have into one single, minified file. This allows for better performance on the client as the files are smaller and are fetched in one single request.
So precompiling assets in development makes no sense at all.
In case if I understood you correctly, generally, when you precompile by default assets directory is being created inside public directory. To get your assets back, you can precompile again.
There is also a cache in tmp directory that you might consider removing.
Later you could use a $ (bundle exec) rake assets:precompile in combination with $ (bundle exec) rake assets:clean instead of $ rm -r public/assets so that new assets would be in effect rake way.
A one line command to look at new changes after your commits in environment would be
$ RAILS_ENV=(environment) rake assets:clean assets:precompile
but generally in development assets are not meant to be served as in production mode, so running previous with RAILS_ENV=production and starting a local server in production mode would be considered as a way to check (but not to make sure) if your assets would be served upon deployment in real production.
I went into the exact same problem and resolved it following #dashi's advice: 'remove directory assets in public, then start server in development mode.' everything is back to normal.

Is it possible to skip the asset precompile step for a single git push on Heroku?

Every time I deploy my Rails 3.2 project to Heroku, rake assets:precompile is run:
$ git push heroku master
...
----> Preparing app for Rails asset pipeline
Running: rake assets:precompile
Asset precompilation completed (189.17s)
...
Sometimes I want to make a push that I know does not change any assets, such as a quick hotfix to a controller. Is it possible to skip the asset:precompile step for a single git push to Heroku?
Thanks.
Sure! You'll need to create a manifest.yml in your_app/pubilc/assets directory.
The file can be blank. But ideally, you precompile everything locally, so deploys to Heroku would be much faster.
Make sure that you also committed the manifest.yml file when you're pushing to Heroku. Something like git add -f your_app/pubilc/assets/manifest.yml and a git push heroku master should suffice.
This worked for me. manifest.yml did nothing for me on my rails 4 project.
https://gist.github.com/Geesu/d0b58488cfae51f361c6
Just precompile locally with rake assets: precompile, check in the resulting assets that are in public/assets, and push to heroku.
This will automatically create the manifest-.yml or json file in your public/assets directory; then heroku will detect that and report Detected manifest file, assuming assets were compiled locally.
Note 1: Some people have a line in development.rb that makes these go to public/dev-assets instead; if so, you need to rename dev-assets to just assets)
Note 2: Make sure your .gitignore file is not excluding the public/assets directory.
In rails 4, create the file manifest-<md5 hash>.json instead of manifest.yml

Heroku can't find files in my Ruby on Rails app - even though they are right there?

When I try to access my site, then check my Heroku logs, I see this error:
ActionView::Template::Error (couldn't find file 'reset'
2012-06-13T02:31:43+00:00 app[web.1]: (in
/app/app/assets/stylesheets/application.css:4)):
(application.css contains the line *= require reset)
Then I thought to run "heroku run bundle exec rake assets:precompile:all" but this gives a similar error:
-----> Preparing app for Rails asset pipeline
Running: rake assets:precompile
rake aborted!
couldn't find file 'main/first.js.coffee'
(in /tmp/build_3428u21sggsoc/app/assets/javascripts/application.js:1)
Tasks: TOP => assets:precompile:primary
(That file is the first one required from my application.js, which has first line "//= require main/first.js.coffee")
In summary: my application runs fine locally, but when I deploy to Heroku, the files can no longer be found. Any ideas why?
Edit: here is the project tree. (There is one more directory before the app one, and that is the main project directory that also contains config, db, log, etc)
Another edit: there is no problem with .gitignore, or .slugignore.
At first, I would suggest you to run your application in production mode on your local computer. There are some errors (in assets but I also found some in routing) which can have impact only for production environment so you can test and fix them locally instead of having to do it from the production server.
About the asset precompilation on Heroku, the solution given by akjoe should result in compiled assets tracked in git repo : with this option, you should disable the asset precompilation which happen on Heroku and let Rails serve you assets (set config.serve_static_assets = true in your production.rb file) but this is not the best way to deal with the asset pipeline as you lost one of his major benefice which is freeing your rails application of request for asset.
To make it working properly, you should setup something like heroku explain : Using Rack::Cache with Memcached for Static Asset Caching in Rails 3.1+
I would also suggest you to try the assets precompilation locally in production environment RAILS_ENV=production bundle exec rake assets:precompile. To see if you got any error.
Finally you may want to check this different links to find useful information :
Rails 3.1+ Asset Pipeline on Heroku Cedar
Railscasts : #279 Understanding the Asset Pipeline
Rails Guide
I've had almost exactly the same problem and similar errors with stylesheets edits not taking effect... I found that I would edit css (or as in your case references to css files) which seemed to be ignored by Heroku. Turns out Heroku was ONLY referencing the stylesheets in the public/assets directory. I cleared this directory and was able to get it working.
I later found that you need to precompile your assets directory BEFORE you checkin to git. You would do this as follows:
Precompile assets directory: rake assets:precompile
Add the project files to the current Git repository: git add .
Checkin the file changes to the current Git repository: git commit
-am "description goes here"
Push the files to Heroku: git push heroku master (substitute
'master' for the branch you wish to push to Heroku).
Hope that helps!

Confusion about rake assets:clean / cleanup on the asset pipeline in rails

Could somebody explain to me what the command rake assets:clean really does? Unfortunately the Rails Guides dont mention it. There is also the command rake assets:cleanup. Whats the difference?
Furthermore could somebody tell me when do I have to run rake assets:precompile in production. Do I run it on the server console after I deployed all my application files to my production server? Or do I precompile on my local machine and then do a deploy of all files?
Thanks all
Note: This answer is rails 3 specific. For rails 4 and later, look at other answers here.
If you precompile on your local machine, then you can commit these generated assets into the repository and proceed with deployment. No need to compile them on production machine.
But it introduces a problem: now when you change source files (coffescript / scss), the app won't pick up the changes, because it will serve precompiled files instead. rake assets:clean deletes these precompiled files.
In my projects assets are precompiled as a part of deployment. Capistrano makes it very easy.
Also, I never heard of rake assets:cleanup.
Run rake assets:clobber to actually clean the assets.
http://www.dixis.com/?p=735
Sergio's answer was completely correct in Rails 3. rake assets:clean deleted all assets that had been previously precompiled into the public/assets directory.
In Rails 4, you run rake assets:clobber to do the same thing.
If you run rake assets:precompile with the following config (by default turned on in staging and production):
# config/environments/production.rb
config.assets.digest = true
You compiled assets get timestamped. This means you can compile your new assets while leaving the old assets in place. You usually want to do this in production so you website will still access the old files while your running precompile to create your new files (because you've added new css/javascript). You now want to get rid of the old files that are no longer in use. The clean it removes the old versions of the precompiled assets while leaving the new assets in place.
rake assets:clean removes compiled assets. It is run by cap deploy:assets:clean to remove compiled assets, generally from a remote server.
cap deploy:clean removes old releases, generally from a remote server. It is not rake assets:clean
rake != cap
rake assets:clean is now run by cap deploy:cleanup_assets. Add require 'capistrano/rails/assets' to your Capfile and you get this cap-task. My capistrano version is v3.2.1.
clean up those untracked files with git clean -f for files and git clean -f -d for directories

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