Class: HalClient::Representation

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/hal_client/representation.rb

Overview

HAL representation of a single resource. Provides access to properties, links and embedded representations.

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Representation

Create a new Representation

options - name parameters

:parsed_json - A hash structure representing a single HAL
  document.
:href - The href of this representation.
:hal_client - The HalClient instance to use when navigating.



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# File 'lib/hal_client/representation.rb', line 21

def initialize(options)
  @raw = options[:parsed_json]
  @hal_client = options[:hal_client]
  @href = options[:href]

  (fail ArgumentError, "Either parsed_json or href must be provided") if
    @raw.nil? && @href.nil?

  (fail InvalidRepresentationError, "Invalid HAL representation: #{raw.inspect}") if
    @raw && ! hashish?(@raw)
end

Instance Method Details

#[](name_or_rel) ⇒ Object

Returns the value of the specified property or representations

of resources related via the specified link rel or nil

name_or_rel - The name of property or link rel of interest



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# File 'lib/hal_client/representation.rb', line 99

def [](name_or_rel)
  item_key = name_or_rel
  fetch(item_key, nil)
end

#fetch(name_or_rel, default = MISSING, &default_proc) ⇒ Object

Returns the value of the specified property or representations

of resources related via the specified link rel or the
specified default value.

name_or_rel - The name of property or link rel of interest default - an optional object that should be return if the

specified property or link does not exist

default_proc - an option proc that will be called with name

to produce default value if the specified property or link does not
exist

Raises KeyError if the specified property or link does not exist

and no default nor default_proc is provided.



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# File 'lib/hal_client/representation.rb', line 86

def fetch(name_or_rel, default=MISSING, &default_proc)
  item_key = name_or_rel
  default_proc ||= ->(_){default} if default != MISSING

  property(item_key) {
    related(item_key, &default_proc)
  }
end

#href ⇒ Object

Returns the URL of the resource this representation represents.



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# File 'lib/hal_client/representation.rb', line 69

def href
  @href ||= links.hrefs('self').first
end

#post(data, options = {}) ⇒ Object

Posts a Representation or String to this resource.

data - a String or an object that responds to #to_hal options - set of options to pass to ‘HalClient#post`



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# File 'lib/hal_client/representation.rb', line 37

def post(data, options={})
  @hal_client.post(href, data, options)
end

#property(name, default = MISSING, &default_proc) ⇒ Object

Returns The value of the specified property or the specified

default value.

name - The name of property of interest default - an optional object that should be return if the

specified property does not exist

default_proc - an option proc that will be called with name

to produce default value if the specified property does not
exist

Raises KeyError if the specified property does not exist

and no default nor default_proc is provided.



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# File 'lib/hal_client/representation.rb', line 62

def property(name, default=MISSING, &default_proc)
  default_proc ||= ->(_){ default} if default != MISSING

  raw.fetch(name.to_s, &default_proc)
end

#property?(name) ⇒ Boolean Also known as: has_property?

Returns true if this representation contains the specified property.

name - the name of the property to check

Returns:

  • (Boolean) 


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# File 'lib/hal_client/representation.rb', line 45

def property?(name)
  raw.key? name
end

#raw_related_hrefs(link_rel, &default_proc) ⇒ Object

Returns values of the href member of links and the URL of embedded representations related via the specified link rel. The only difference between this and #related_hrefs is that this method makes no attempt to expand templated links. For templated links the returned collection will include the template pattern as encoded in the HAL document.

link_rel - The link rel of interest default_proc - an option proc that will be called with name

to produce default value if the specified property or link does not
exist

Raises KeyError if the specified link does not exist

and no default_proc is provided.



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# File 'lib/hal_client/representation.rb', line 172

def raw_related_hrefs(link_rel, &default_proc)
  default_proc ||= ->(link_rel){
    raise KeyError, "No resources are related via `#{link_rel}`"
  }

  embedded = embedded(link_rel) { nil }
  linked = links.hrefs(link_rel) { nil }
  return default_proc.call(link_rel) if embedded.nil? and linked.nil?

  Array(linked) + Array(embedded).map(&:href)
end

#related(link_rel, options = {}, &default_proc) ⇒ Object

Returns representations of resources related via the specified

link rel or the specified default value.

link_rel - The link rel of interest options - optional keys and values with which to expand any

templated links that are encountered

default_proc - an option proc that will be called with name

to produce default value if the specified property or link does not
exist

Raises KeyError if the specified link does not exist

and no default_proc is provided.



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# File 'lib/hal_client/representation.rb', line 129

def related(link_rel, options = {}, &default_proc)
  default_proc ||= ->(link_rel){
    raise KeyError, "No resources are related via `#{link_rel}`"
  }

  embedded = embedded(link_rel) { nil }
  linked = linked(link_rel, options) { nil }
  return default_proc.call(link_rel) if embedded.nil? and linked.nil?

  RepresentationSet.new (Array(embedded) + Array(linked))
end

#related?(link_rel) ⇒ Boolean Also known as: has_related?

Returns true if this representation contains a link (including embedded links) whose rel is link_rel.

link_rel - The link rel of interest

Returns:

  • (Boolean) 


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# File 'lib/hal_client/representation.rb', line 108

def related?(link_rel)
  _ = related link_rel
  true

rescue KeyError
  false
end

#related_hrefs(link_rel, options = {}, &default_proc) ⇒ Object

Returns urls of resources related via the specified

link rel or the specified default value.

link_rel - The link rel of interest options - optional keys and values with which to expand any

templated links that are encountered

default_proc - an option proc that will be called with name

to produce default value if the specified property or link does not
exist

Raises KeyError if the specified link does not exist

and no default_proc is provided.



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# File 'lib/hal_client/representation.rb', line 153

def related_hrefs(link_rel, options={}, &default_proc)
  related(link_rel, options, &default_proc).
    map(&:href)
end

#to_json ⇒ Object

Returns the raw json representation of this representation



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# File 'lib/hal_client/representation.rb', line 191

def to_json
  raw.to_json
end

#to_s ⇒ Object

Returns a short human readable description of this representation.



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# File 'lib/hal_client/representation.rb', line 186

def to_s
  "#<" + self.class.name + ": " + href + ">"
end