Class: Praxis::Renderer

Inherits:
Object
  • Object
show all
Defined in:
lib/praxis/renderer.rb

Defined Under Namespace

Classes: CircularRenderingError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(include_nil: false) ⇒ Renderer

Returns a new instance of Renderer.



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# File 'lib/praxis/renderer.rb', line 21

def initialize(include_nil: false)
  @cache = Hash.new do |hash, key|
    hash[key] = {}
  end

  @include_nil = include_nil
end

Instance Attribute Details

#cache ⇒ Object (readonly)

Returns the value of attribute cache.



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# File 'lib/praxis/renderer.rb', line 5

def cache
  @cache
end

#include_nil ⇒ Object (readonly)

Returns the value of attribute include_nil.



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# File 'lib/praxis/renderer.rb', line 5

def include_nil
  @include_nil
end

Instance Method Details

#_render(object, fields, context: Attributor::DEFAULT_ROOT_CONTEXT) ⇒ Object 



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# File 'lib/praxis/renderer.rb', line 48

def _render(object, fields, context: Attributor::DEFAULT_ROOT_CONTEXT)
  if fields == true
    return case object
           when Attributor::Dumpable
             object.dump
           else
             object
           end
  end

  fields.each_with_object({}) do |(key, subfields), hash|
    begin
      value = object._get_attr(key)
    rescue StandardError => e
      raise Attributor::DumpError.new(context: context, name: key, type: object.class, original_exception: e)
    end

    if value.nil?
      hash[key] = nil if include_nil
      next
    end

    if subfields == true
      hash[key] = case value
                  when Attributor::Dumpable
                    value.dump
                  else
                    value
                  end
    else
      new_context = context + [key]
      hash[key] = render(value, subfields, context: new_context)
    end
  end
end

#render(object, fields, context: Attributor::DEFAULT_ROOT_CONTEXT) ⇒ Object

Renders an object using a given list of fields.

Parameters:

  • object (Object) —

    the object to render

  • fields (Hash) —

    the correct set of fields, as from FieldExpander



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# File 'lib/praxis/renderer.rb', line 33

def render(object, fields, context: Attributor::DEFAULT_ROOT_CONTEXT)
  if object.is_a? Praxis::Blueprint
    @cache[object._cache_key][fields] ||= _render(object, fields, context: context)
  elsif object.class < Attributor::Collection
    object.each_with_index.collect do |sub_object, i|
      sub_context = context + ["at(#{i})"]
      render(sub_object, fields, context: sub_context)
    end
  else
    _render(object, fields, context: context)
  end
rescue SystemStackError
  raise CircularRenderingError.new(object, context)
end