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 90

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 77

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

#has_related?(link_rel) ⇒ Boolean

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 99

def has_related?(link_rel)
  _ = related link_rel
  true

rescue KeyError
  false
end

#href ⇒ Object

Returns the URL of the resource this representation represents.



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# File 'lib/hal_client/representation.rb', line 60

def href
  @href ||= link_section.fetch("self").fetch("href")
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 53

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

  raw.fetch(name.to_s, &default_proc)
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 119

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

  embedded = embedded_or_nil(link_rel)
  linked = linked_or_nil(link_rel, options)

  if !embedded.nil? or !linked.nil?
    RepresentationSet.new (Array(embedded) + Array(linked))
  else
    default_proc.call link_rel
  end
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 146

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 158

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 153

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