Merge pull request #273 from Netflix/release-1.3

Release 1.3

Author: shishirmk

README.md

@@ -30,6 +30,9 @@ Fast JSON API serialized 250 records in 3.01 ms
   * [Collection Serialization](#collection-serialization)
   * [Caching](#caching)
   * [Params](#params)
+  * [Conditional Attributes](#conditional-attributes)
+  * [Conditional Relationships](#conditional-relationships)
+  * [Sparse Fieldsets](#sparse-fieldsets)
 * [Contributing](#contributing)
 
 
@@ -205,6 +208,18 @@ class MovieSerializer
 end
 ```
 
+Attributes can also use a different name by passing the original method or accessor with a proc shortcut:
+
+```ruby
+class MovieSerializer
+  include FastJsonapi::ObjectSerializer
+
+  attributes :name
+
+  attribute :released_in_year, &:year
+end
+```
+
 ### Links Per Object
 Links are defined in FastJsonapi using the `link` method. By default, link are read directly from the model property of the same name.In this example, `public_url` is expected to be a property of the object being serialized.
 
@@ -259,6 +274,26 @@ hash = MovieSerializer.new([movie, movie], options).serializable_hash
 json_string = MovieSerializer.new([movie, movie], options).serialized_json
 ```
 
+#### Control Over Collection Serialization
+
+You can use `is_collection` option to have better control over collection serialization.
+
+If this option is not provided or `nil` autedetect logic is used to try understand
+if provided resource is a single object or collection.
+
+Autodetect logic is compatible with most DB toolkits (ActiveRecord, Sequel, etc.) but
+**cannot** guarantee that single vs collection will be always detected properly.
+
+```ruby
+options[:is_collection]
+```
+
+was introduced to be able to have precise control this behavior
+
+- `nil` or not provided: will try to autodetect single vs collection (please, see notes above)
+- `true` will always treat input resource as *collection*
+- `false` will always treat input resource as *single object*
+
 ### Caching
 Requires a `cache_key` method be defined on model:
 
@@ -284,7 +319,6 @@ block you opt-in to using params by adding it as a block parameter.
 
 ```ruby
 class MovieSerializer
-  class MovieSerializer
   include FastJsonapi::ObjectSerializer
 
   attributes :name, :year
@@ -308,6 +342,68 @@ serializer.serializable_hash
 Custom attributes and relationships that only receive the resource are still possible by defining
 the block to only receive one argument.
 
+### Conditional Attributes
+
+Conditional attributes can be defined by passing a Proc to the `if` key on the `attribute` method. Return `true` if the attribute should be serialized, and `false` if not. The record and any params passed to the serializer are available inside the Proc as the first and second parameters, respectively.
+
+```ruby
+class MovieSerializer
+  include FastJsonapi::ObjectSerializer
+
+  attributes :name, :year
+  attribute :release_year, if: Proc.new do |record|
+    # Release year will only be serialized if it's greater than 1990
+    record.release_year > 1990
+  end
+
+  attribute :director, if: Proc.new do |record, params|
+    # The director will be serialized only if the :admin key of params is true
+    params && params[:admin] == true
+  end
+end
+
+# ...
+current_user = User.find(cookies[:current_user_id])
+serializer = MovieSerializer.new(movie, { params: { admin: current_user.admin? }})
+serializer.serializable_hash
+```
+
+### Conditional Relationships
+
+Conditional relationships can be defined by passing a Proc to the `if` key. Return `true` if the relationship should be serialized, and `false` if not. The record and any params passed to the serializer are available inside the Proc as the first and second parameters, respectively.
+
+```ruby
+class MovieSerializer
+  include FastJsonapi::ObjectSerializer
+
+  # Actors will only be serialized if the record has any associated actors
+  has_many :actors, if: Proc.new { |record| record.actors.any? }
+
+  # Owner will only be serialized if the :admin key of params is true
+  belongs_to :owner, if: Proc.new { |record, params| params && params[:admin] == true }
+end
+
+# ...
+current_user = User.find(cookies[:current_user_id])
+serializer = MovieSerializer.new(movie, { params: { admin: current_user.admin? }})
+serializer.serializable_hash
+```
+
+### Sparse Fieldsets
+
+Attributes and relationships can be selectively returned per record type by using the `fields` option.
+
+```ruby
+class MovieSerializer
+  include FastJsonapi::ObjectSerializer
+
+  attributes :name, :year
+end
+
+serializer = MovieSerializer.new(movie, { fields: { movie: [:name] } })
+serializer.serializable_hash
+```
+
 ### Customizable Options
 
 Option | Purpose | Example

lib/extensions/has_one.rb

@@ -1,20 +1,18 @@
 # frozen_string_literal: true
 
-if defined?(::ActiveRecord)
-  ::ActiveRecord::Associations::Builder::HasOne.class_eval do
-    # Based on
-    # https://github.com/rails/rails/blob/master/activerecord/lib/active_record/associations/builder/collection_association.rb#L50
-    # https://github.com/rails/rails/blob/master/activerecord/lib/active_record/associations/builder/singular_association.rb#L11
-    def self.define_accessors(mixin, reflection)
-      super
-      name = reflection.name
-      mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
-        def #{name}_id
-          # if an attribute is already defined with this methods name we should just use it
-          return read_attribute(__method__) if has_attribute?(__method__)
-          association(:#{name}).reader.try(:id)
-        end
-      CODE
-    end
+::ActiveRecord::Associations::Builder::HasOne.class_eval do
+  # Based on
+  # https://github.com/rails/rails/blob/master/activerecord/lib/active_record/associations/builder/collection_association.rb#L50
+  # https://github.com/rails/rails/blob/master/activerecord/lib/active_record/associations/builder/singular_association.rb#L11
+  def self.define_accessors(mixin, reflection)
+    super
+    name = reflection.name
+    mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
+      def #{name}_id
+        # if an attribute is already defined with this methods name we should just use it
+        return read_attribute(__method__) if has_attribute?(__method__)
+        association(:#{name}).reader.try(:id)
+      end
+    CODE
   end
 end

lib/fast_jsonapi.rb

@@ -2,5 +2,9 @@
 
 module FastJsonapi
   require 'fast_jsonapi/object_serializer'
-  require 'extensions/has_one'
+  if defined?(::Rails)
+    require 'fast_jsonapi/railtie'
+  elsif defined?(::ActiveRecord)
+    require 'extensions/has_one'
+  end
 end

lib/fast_jsonapi/attribute.rb

@@ -0,0 +1,29 @@
+module FastJsonapi
+  class Attribute
+    attr_reader :key, :method, :conditional_proc
+
+    def initialize(key:, method:, options: {})
+      @key = key
+      @method = method
+      @conditional_proc = options[:if]
+    end
+
+    def serialize(record, serialization_params, output_hash)
+      if include_attribute?(record, serialization_params)
+        output_hash[key] = if method.is_a?(Proc)
+          method.arity.abs == 1 ? method.call(record) : method.call(record, serialization_params)
+        else
+          record.public_send(method)
+        end
+      end
+    end
+
+    def include_attribute?(record, serialization_params)
+      if conditional_proc.present?
+        conditional_proc.call(record, serialization_params)
+      else
+        true
+      end
+    end
+  end
+end

lib/fast_jsonapi/link.rb

@@ -0,0 +1,18 @@
+module FastJsonapi
+  class Link
+    attr_reader :key, :method
+
+    def initialize(key:, method:)
+      @key = key
+      @method = method
+    end
+
+    def serialize(record, serialization_params, output_hash)
+      output_hash[key] = if method.is_a?(Proc)
+        method.arity == 1 ? method.call(record) : method.call(record, serialization_params)
+      else
+        record.public_send(method)
+      end
+    end
+  end
+end