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d5bae0c2f0
The options passed to the render are partitioned into adapter options and serializer options. 'include' and 'root' are sent to the adapter, not sure what options would go directly to serializer, but leaving this in until I understand that better.
177 lines
4.5 KiB
Markdown
177 lines
4.5 KiB
Markdown
# ActiveModel::Serializers
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[](https://travis-ci.org/rails-api/active_model_serializers)
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ActiveModel::Serializers brings convention over configuration to your JSON generation.
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AMS does this through two components: **serializers** and **adapters**. Serializers describe which attributes and relationships should be serialized. Adapters describe how attributes and relationships should be serialized.
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# MAINTENANCE, PLEASE READ
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This is the master branch of AMS. It will become the `0.10.0` release when it's
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ready, but it's not. You probably don't want to use it yet.
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There are two released versions of AMS that you may want to use: `0.9.x` and
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`0.8.x`. `9` was recently `master`, so if you were using master, you probably want
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to use it. `8` was the version that was on RubyGems, so if you were using that,
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that's probably what you want.
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`0.10.x` will be based on the `0.8.0` code, but with a more flexible
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architecture. We'd love your help.
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For more, please see [the rails-api-core mailing list](https://groups.google.com/d/msg/rails-api-core/8zu1xjIOTAM/siZ0HySKgaAJ).
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Thanks!
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## Example
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Given two models, a `Post(title: string, body: text)` and a
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`Comment(name:string, body:text, post_id:integer)`, you will have two
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serializers:
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```ruby
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class PostSerializer < ActiveModel::Serializer
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attributes :title, :body
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has_many :comments
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url :post
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end
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```
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and
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```ruby
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class CommentSerializer < ActiveModel::Serializer
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attributes :name, :body
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belongs_to :post
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url [:post, :comment]
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end
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```
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Generally speaking, you as a user of AMS will write (or generate) these
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serializer classes. By default, they will use the JsonApiAdapter, implemented
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by AMS. If you want to use a different adapter, such as a HalAdapter, you can
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change this in an initializer:
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```ruby
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ActiveModel::Serializer.config.adapter = ActiveModel::Serializer::Adapter::HalAdapter
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```
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or
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```ruby
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ActiveModel::Serializer.config.adapter = :hal
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```
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You won't need to implement an adapter unless you wish to use a new format or
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media type with AMS.
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In your controllers, when you use `render :json`, Rails will now first search
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for a serializer for the object and use it if available.
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```ruby
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class PostsController < ApplicationController
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def show
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@post = Post.find(params[:id])
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render json: @post
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end
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end
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```
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In this case, Rails will look for a serializer named `PostSerializer`, and if
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it exists, use it to serialize the `Post`.
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### Built in Adapters
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The `:json_api` adapter will include the associated resources in the `"linked"`
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member when the resource names are included in the `include` option.
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```ruby
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render @posts, include: 'authors,comments'
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```
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## Installation
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Add this line to your application's Gemfile:
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```
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gem 'active_model_serializers'
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```
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And then execute:
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```
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$ bundle
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```
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## Creating a Serializer
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The easiest way to create a new serializer is to generate a new resource, which
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will generate a serializer at the same time:
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```
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$ rails g resource post title:string body:string
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```
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This will generate a serializer in `app/serializers/post_serializer.rb` for
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your new model. You can also generate a serializer for an existing model with
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the serializer generator:
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```
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$ rails g serializer post
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```
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The generated seralizer will contain basic `attributes` and
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`has_many`/`belongs_to` declarations, based on the model. For example:
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```ruby
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class PostSerializer < ActiveModel::Serializer
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attributes :title, :body
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has_many :comments
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url :post
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end
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```
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and
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```ruby
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class CommentSerializer < ActiveModel::Serializer
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attributes :name, :body
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belongs_to :post_id
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url [:post, :comment]
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end
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```
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The attribute names are a **whitelist** of attributes to be serialized.
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The `has_many` and `belongs_to` declarations describe relationships between
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resources. By default, when you serialize a `Post`, you will get its `Comment`s
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as well.
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The `url` declaration describes which named routes to use while generating URLs
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for your JSON. Not every adapter will require URLs.
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## Getting Help
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If you find a bug, please report an [Issue](https://github.com/rails-api/active_model_serializers/issues/new).
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If you have a question, please [post to Stack Overflow](http://stackoverflow.com/questions/tagged/active-model-serializers).
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Thanks!
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## Contributing
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1. Fork it ( https://github.com/rails-api/active_model_serializers/fork )
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2. Create your feature branch (`git checkout -b my-new-feature`)
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3. Commit your changes (`git commit -am 'Add some feature'`)
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4. Push to the branch (`git push origin my-new-feature`)
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5. Create a new Pull Request
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