Class: Jstreamer::RailsJson

Inherits:
BaseJson show all
Defined in:
lib/jstreamer/rails_json.rb

Overview

Rails extensions class - provides some helpers methods:

  • view methods delegation

  • view variables access

  • render helpers

Examples:

In controller

class MyApiController
  def show1
    SomeJson.render(model, view_context:)    # we always need to provide view_context for rails magic to work
  end

  def show2
    render(json: SomeJson.generate(model, view_context:)) # this is actually sugar equivalent of above
  end
end

In template

class SomeMyJson < RailsJson
  def render
    # all methods are automatically coming from view context

    prop(:about_path, about_path)               # view helpers
    prop(:user_id, current_user.id)             # controller methods

    view_context_get(:@notifications)           # variables are not magically added, they need a method
  end
end

Instance Attribute Summary

Attributes inherited from BaseJson

#current_model, #current_stream, #index, #options

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BaseJson

#array, #call, #call_collection, delegated_options, #encode_value, #from, generate, generate_collection, #initialize, #merge_json, #object, #partial, #prop, #to_s, #transform_key, #view?

Constructor Details

This class inherits a constructor from Jstreamer::BaseJson

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method) ⇒ Object (private)

Automatically delegates methods to view_context provided in options



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# File 'lib/jstreamer/rails_json.rb', line 62

def method_missing(method, ...)
  return super if view_context.nil? || !view_context.respond_to?(method)

  # TODO: analogue of self.class.delegate(method, to: :view_context)
  self.class.define_method(method) do |*args|
    view_context.__send__(method, *args)
  end

  public_send(method, ...)
end

Class Method Details

.render(obj = nil, **opts) ⇒ Object

Helper to call controller’s render method on a single object

Parameters:

  • obj (Object) (defaults to: nil) —

    data object

  • opts (kwargs) —

    options



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# File 'lib/jstreamer/rails_json.rb', line 33

def self.render(obj = nil, **opts)
  opts.fetch(:view_context).controller.render(json: generate(obj, **opts))
end

.render_collection(collection, **opts) ⇒ Object

Helper to call controller’s render method on a collection

Parameters:

  • collection (Array)
  • opts (kwargs) —

    options



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# File 'lib/jstreamer/rails_json.rb', line 40

def self.render_collection(collection, **opts)
  opts.fetch(:view_context).controller.render(json: generate_collection(collection, **opts))
end

Instance Method Details

#view_context ⇒ view_context

Returns view_context provided in options

Returns:



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# File 'lib/jstreamer/rails_json.rb', line 46

def view_context
  # NOTE: useful view_context injection discussion
  # https://github.com/drapergem/draper/issues/124
  options.fetch(:view_context)
end

#view_context_get(var_name) ⇒ Object

Gets instance variable value from view_context

Parameters:

  • var_name (Symbol) —

    variable name as :@abc

Returns:

  • variable value



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# File 'lib/jstreamer/rails_json.rb', line 55

def view_context_get(var_name)
  view_context.instance_variable_get(var_name)
end