active_model_serializers/lib/active_model/serializer/fieldset.rb
Benjamin Fleischer af99c0d9e6 Ensure inheritance hooks run
I was seeing transient failures where adapters may not be registered.

e.g. https://travis-ci.org/rails-api/active_model_serializers/builds/77735382

Since we're using the Adapter, JsonApi, and Json classes
as namespaces, some of the conventions we use for modules don't apply.
Basically, we don't want to define the class anywhere besides itself.
Otherwise, the inherited hooks may not run, and some adapters may not
be registered.

For example:

If we have a class Api `class Api; end`
And Api is also used as a namespace for `Api::Product`
And the classes are defined in different files.

In one file:

```ruby
class Api
  autoload :Product
  def self.inherited(subclass)
    puts
    p [:inherited, subclass.name]
    puts
  end
end
```

And in another:

```ruby
class Api
  class Product < Api
    def sell_sell_sell!
      # TODO: sell
    end
  end
end
```

If we load the Api class file first, the inherited hook will be defined on the class
so that when we load the Api::Product class, we'll see the output:

```plain
[ :inherited, Api::Product]
```

However, if we load the Api::Product class first, since it defines the `Api` class
and then inherited from it, the Api file was never loaded, the hook never defined,
and thus never run.

By defining the class as `class Api::Product < Api` We ensure the the Api class
MUST be defined, and thus, the hook will be defined and run and so sunshine and unicorns.

Appendix:

The below would work, but triggers a circular reference warning.
It's also not recommended to mix require with autoload.

```ruby
require 'api'
class Api
  class Product < Api
    def sell_sell_sell!
      # TODO: sell
    end
  end
end
```

This failure scenario was introduced by removing the circular reference warnings in
https://github.com/rails-api/active_model_serializers/pull/1067

Style note:

To make diffs on the adapters smalleer and easier to read, I've maintained the same
identention that was in the original file.  I've decided to prefer ease of reading
the diff over style, esp. since we may later return to the preferred class declaration style.

 with '#' will be ignored, and an empty message aborts the commit.
2015-09-09 08:55:20 -05:00

41 lines
955 B
Ruby

module ActiveModel
class Serializer
class Fieldset
def initialize(fields, root = nil)
@root = root
@raw_fields = fields
end
def fields
@fields ||= parsed_fields
end
def fields_for(serializer)
key = serializer.json_key
fields[key.to_sym] || fields[key.pluralize.to_sym]
end
private
ActiveModelSerializers.silence_warnings do
attr_reader :raw_fields, :root
end
def parsed_fields
if raw_fields.is_a?(Hash)
raw_fields.inject({}) { |h, (k, v)| h[k.to_sym] = v.map(&:to_sym); h }
elsif raw_fields.is_a?(Array)
if root.nil?
raise ArgumentError, 'The root argument must be specified if the fileds argument is an array.'
end
hash = {}
hash[root.to_sym] = raw_fields.map(&:to_sym)
hash
else
{}
end
end
end
end
end