Class: Occi::Core::Parsers::BaseParser Abstract

Inherits:
Object
  • Object
show all
Includes:
Helpers::ArgumentValidator, Helpers::ErrorHandler, Yell::Loggable
Defined in:
lib/occi/core/parsers/base_parser.rb

Overview

This class is abstract.

Not for direct use.

Implementes base components necessary to parse all renderings.

Author:

Direct Known Subclasses

JsonParser, TextParser

Constant Summary collapse

MEDIA_TYPES =

Media type constants

[].freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers::ErrorHandler

#handle, included

Constructor Details

#initialize(args = {}) ⇒ BaseParser

Constructs an instance of the parser that will use a particular model as the reference for every parsed instance. Only instances allowed by the model will be successfuly parsed. In case of ‘Occi::Core::Category` instances, only identifiers are parsed and existing instances from the model are returned.

Parameters:

  • args (Hash) (defaults to: {}) —

    constructor arguments in a Hash

Options Hash (args):

  • :model (Occi::Core::Model) —

    model to use as a primary reference point

  • :media_type (String) —

    type of content to parse



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# File 'lib/occi/core/parsers/base_parser.rb', line 29

def initialize(args = {})
  pre_initialize(args)
  default_args! args

  @model = args.fetch(:model)
  @media_type = args.fetch(:media_type)
  logger.debug { "Initializing parser for #{media_type.inspect}" }

  post_initialize(args)
end

Instance Attribute Details

#media_type ⇒ String

type of content to parse

Returns:

  • (String) —

    the current value of media_type



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# File 'lib/occi/core/parsers/base_parser.rb', line 11

def media_type
  @media_type
end

#model ⇒ Occi::Core::Model, Occi::Infrastructure::Model

model to use as a primary reference point

Returns:



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# File 'lib/occi/core/parsers/base_parser.rb', line 11

def model
  @model
end

Class Method Details

.media_types ⇒ Array

Returns a list of supported media types for this parser.

Returns:

  • (Array) —

    list of supported media types



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# File 'lib/occi/core/parsers/base_parser.rb', line 125

def media_types
  self::MEDIA_TYPES
end

.parses?(media_type) ⇒ TrueClass, FalseClass

Checks whether the given media type is supported by this parser.

Parameters:

  • media_type (String) —

    media type string as provided by the transport protocol

Returns:



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# File 'lib/occi/core/parsers/base_parser.rb', line 135

def parses?(media_type)
  media_types.include? media_type
end

Instance Method Details

#action_instances(_body, _headers) ⇒ Set

Parses action instances from the given body/headers. Only actions already declared in the model are allowed.

Parameters:

  • body (String) —

    raw ‘String`-like body as provided by the transport protocol

  • headers (Hash) —

    raw headers as provided by the transport protocol

Returns:

  • (Set) —

    set of parsed instances

Raises:



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# File 'lib/occi/core/parsers/base_parser.rb', line 67

def action_instances(_body, _headers)
  raise Occi::Core::Errors::ParserError, 'This method needs to be implemented in subclasses'
end

#actions(body, headers) ⇒ Object

See ‘#categories`.



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# File 'lib/occi/core/parsers/base_parser.rb', line 93

def actions(body, headers)
  categories body, headers, Occi::Core::Action
end

#categories(_body, _headers, _expectation = nil) ⇒ Set

Parses categories from the given body/headers and returns corresponding instances from the known model.

Parameters:

  • body (String) —

    raw ‘String`-like body as provided by the transport protocol

  • headers (Hash) —

    raw headers as provided by the transport protocol

  • expectation (Class) —

    expected class of the returned instance(s)

Returns:

  • (Set) —

    set of instances

Raises:



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# File 'lib/occi/core/parsers/base_parser.rb', line 78

def categories(_body, _headers, _expectation = nil)
  raise Occi::Core::Errors::ParserError, 'This method needs to be implemented in subclasses'
end

#entities(_body, _headers, _expectation = nil) ⇒ Set

Parses entities from the given body/headers. Only kinds, mixins, and actions already declared in the model are allowed.

Parameters:

  • body (String) —

    raw ‘String`-like body as provided by the transport protocol

  • headers (Hash) —

    raw headers as provided by the transport protocol

  • expectation (Class) —

    expected class of the returned instance(s)

Returns:

  • (Set) —

    set of instances

Raises:



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# File 'lib/occi/core/parsers/base_parser.rb', line 47

def entities(_body, _headers, _expectation = nil)
  raise Occi::Core::Errors::ParserError, 'This method needs to be implemented in subclasses'
end

#kinds(body, headers) ⇒ Object

See ‘#categories`.



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# File 'lib/occi/core/parsers/base_parser.rb', line 83

def kinds(body, headers)
  categories body, headers, Occi::Core::Kind
end

#links(body, headers) ⇒ Object

See ‘#entities`.



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# File 'lib/occi/core/parsers/base_parser.rb', line 57

def links(body, headers)
  entities body, headers, Occi::Core::Link
end

#lookup(identifier, klass) ⇒ Object

Looks up the given category identifier in the model. Unsuccessfull lookup will raise an error, as will an unexpected class of the found instance.

Parameters:

  • identifier (String) —

    category identifier to look up in the model

  • klass (Class) —

    expected class (raises error otherwise)

Returns:

  • (Object) —

    found instance



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# File 'lib/occi/core/parsers/base_parser.rb', line 113

def lookup(identifier, klass)
  found = handle(Occi::Core::Errors::ParsingError) { model.find_by_identifier!(identifier) }
  unless found.is_a?(klass)
    raise Occi::Core::Errors::ParsingError, "#{identifier.inspect} is not of expected class #{klass}"
  end
  found
end

#mixins(body, headers) ⇒ Object

See ‘#categories`.



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# File 'lib/occi/core/parsers/base_parser.rb', line 88

def mixins(body, headers)
  categories body, headers, Occi::Core::Mixin
end

#parses?(media_type) ⇒ TrueClass, FalseClass

Checks whether the given media type is supported by this parser instance.

Parameters:

  • media_type (String) —

    media type string as provided by the transport protocol

Returns:



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# File 'lib/occi/core/parsers/base_parser.rb', line 103

def parses?(media_type)
  self.media_type == media_type
end

#resources(body, headers) ⇒ Object

See ‘#entities`.



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# File 'lib/occi/core/parsers/base_parser.rb', line 52

def resources(body, headers)
  entities body, headers, Occi::Core::Resource
end