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diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md index 805b0f0d62..bf046a3341 100644 --- a/guides/source/asset_pipeline.md +++ b/guides/source/asset_pipeline.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON https://guides.rubyonrails.org.** The Asset Pipeline ================== @@ -20,10 +20,9 @@ What is the Asset Pipeline? The asset pipeline provides a framework to concatenate and minify or compress JavaScript and CSS assets. It also adds the ability to write these assets in -other languages and pre-processors such as CoffeeScript, Sass and ERB. +other languages and pre-processors such as CoffeeScript, Sass, and ERB. It allows assets in your application to be automatically combined with assets -from other gems. For example, jquery-rails includes a copy of jquery.js -and enables AJAX features in Rails. +from other gems. The asset pipeline is implemented by the [sprockets-rails](https://github.com/rails/sprockets-rails) gem, @@ -35,7 +34,7 @@ rails new appname --skip-sprockets ``` Rails automatically adds the `sass-rails`, `coffee-rails` and `uglifier` -gems to your Gemfile, which are used by Sprockets for asset compression: +gems to your `Gemfile`, which are used by Sprockets for asset compression: ```ruby gem 'sass-rails' @@ -44,8 +43,8 @@ gem 'coffee-rails' ``` Using the `--skip-sprockets` option will prevent Rails from adding -them to your Gemfile, so if you later want to enable -the asset pipeline you will have to add those gems to your Gemfile. Also, +them to your `Gemfile`, so if you later want to enable +the asset pipeline you will have to add those gems to your `Gemfile`. Also, creating an application with the `--skip-sprockets` option will generate a slightly different `config/application.rb` file, with a require statement for the sprockets railtie that is commented-out. You will have to remove @@ -225,7 +224,7 @@ Pipeline assets can be placed inside an application in one of three locations: `app/assets`, `lib/assets` or `vendor/assets`. * `app/assets` is for assets that are owned by the application, such as custom -images, JavaScript files or stylesheets. +images, JavaScript files, or stylesheets. * `lib/assets` is for your own libraries' code that doesn't really fit into the scope of the application or those libraries which are shared across applications. @@ -435,7 +434,7 @@ Sprockets uses manifest files to determine which assets to include and serve. These manifest files contain _directives_ - instructions that tell Sprockets which files to require in order to build a single CSS or JavaScript file. With these directives, Sprockets loads the files specified, processes them if -necessary, concatenates them into one single file and then compresses them +necessary, concatenates them into one single file, and then compresses them (based on value of `Rails.application.config.assets.js_compressor`). By serving one file rather than many, the load time of pages can be greatly reduced because the browser makes fewer requests. Compression also reduces file size, enabling @@ -674,20 +673,20 @@ content changes. ### Precompiling Assets -Rails comes bundled with a task to compile the asset manifests and other +Rails comes bundled with a command to compile the asset manifests and other files in the pipeline. Compiled assets are written to the location specified in `config.assets.prefix`. By default, this is the `/assets` directory. -You can call this task on the server during deployment to create compiled +You can call this command on the server during deployment to create compiled versions of your assets directly on the server. See the next section for information on compiling locally. -The task is: +The command is: ```bash -$ RAILS_ENV=production bin/rails assets:precompile +$ RAILS_ENV=production rails assets:precompile ``` Capistrano (v2.15.1 and above) includes a recipe to handle this in deployment. @@ -699,7 +698,7 @@ load 'deploy/assets' This links the folder specified in `config.assets.prefix` to `shared/assets`. If you already use this shared folder you'll need to write your own deployment -task. +command. It is important that this folder is shared between deployments so that remotely cached pages referencing the old compiled assets still work for the life of @@ -729,8 +728,8 @@ Rails.application.config.assets.precompile += %w( admin.js admin.css ) NOTE. Always specify an expected compiled filename that ends with `.js` or `.css`, even if you want to add Sass or CoffeeScript files to the precompile array. -The task also generates a `.sprockets-manifest-md5hash.json` (where `md5hash` is -an MD5 hash) that contains a list with all your assets and their respective +The command also generates a `.sprockets-manifest-randomhex.json` (where `randomhex` is +a 16-byte random hex string) that contains a list with all your assets and their respective fingerprints. This is used by the Rails helper methods to avoid handing the mapping requests back to Sprockets. A typical manifest file looks like: @@ -846,11 +845,11 @@ signals all caches between your server and the client browser that this content number of requests for this asset from your server; the asset has a good chance of being in the local browser cache or some intermediate cache. -This mode uses more memory, performs more poorly than the default and is not +This mode uses more memory, performs more poorly than the default, and is not recommended. If you are deploying a production application to a system without any -pre-existing JavaScript runtimes, you may want to add one to your Gemfile: +pre-existing JavaScript runtimes, you may want to add one to your `Gemfile`: ```ruby group :production do @@ -918,7 +917,7 @@ config.action_controller.asset_host = ENV['CDN_HOST'] -Note: You would need to set `CDN_HOST` on your server to `mycdnsubdomain +NOTE: You would need to set `CDN_HOST` on your server to `mycdnsubdomain .fictional-cdn.com` for this to work. Once you have configured your server and your CDN when you serve a webpage that @@ -1205,10 +1204,10 @@ Adding Assets to Your Gems Assets can also come from external sources in the form of gems. -A good example of this is the `jquery-rails` gem which comes with Rails as the -standard JavaScript library gem. This gem contains an engine class which -inherits from `Rails::Engine`. By doing this, Rails is informed that the -directory for this gem may contain assets and the `app/assets`, `lib/assets` and +A good example of this is the `jquery-rails` gem. +This gem contains an engine class which inherits from `Rails::Engine`. +By doing this, Rails is informed that the directory for this +gem may contain assets and the `app/assets`, `lib/assets` and `vendor/assets` directories of this engine are added to the search path of Sprockets. @@ -1244,11 +1243,7 @@ moving the files from `public/` to the new locations. See [Asset Organization](#asset-organization) above for guidance on the correct locations for different file types. -Next will be avoiding duplicate JavaScript files. Since jQuery is the default -JavaScript library from Rails 3.1 onwards, you don't need to copy `jquery.js` -into `app/assets` and it will be included automatically. - -The third is updating the various environment files with the correct default +Next is updating the various environment files with the correct default options. In `application.rb`: |