Class: Vend::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/vend/base.rb

Overview

This Base class provides the basic mapping between Vend::Resource subclasses and the HTTP endpoints in the Vend API.

Not all CRUD actions are available for every resource, and at current there is no PUT endpoint and hence no update action

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, options = {}) ⇒ Base

:nodoc:



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# File 'lib/vend/base.rb', line 18

def initialize(client, options = {}) #:nodoc:
  @client = client
  @attrs = options[:attrs] || {}
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object

Overrides method_missing to query the attrs hash for the value stored at the specified key before proxying it to the object



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# File 'lib/vend/base.rb', line 173

def method_missing(method_name, *args, &block)
  if attrs.keys.include? method_name.to_s
    attribute_value_for(method_name)
  else
    super(method_name)
  end
end

Instance Attribute Details

#attrs ⇒ Object

Hash of attributes for this instance. Represents the data returned from the Vend API



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# File 'lib/vend/base.rb', line 16

def attrs
  @attrs
end

#client ⇒ Object (readonly)

Reference to the Vend::Client client object providing the HTTP interface to the API



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# File 'lib/vend/base.rb', line 12

def client
  @client
end

Class Method Details

.accepts_scope?(scope_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vend/base.rb', line 65

def self.accepts_scope?(scope_name)
  available_scopes.include?(scope_name)
end

.all(client) ⇒ Object

Returns a collection containing all of the specified resource objects. Will paginate.



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# File 'lib/vend/base.rb', line 51

def self.all(client)
  initialize_collection(client, collection_name)
end

.attribute_casts ⇒ Object 



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# File 'lib/vend/base.rb', line 27

def self.attribute_casts
  @attribute_casts ||= {}
end

.available_scopes ⇒ Object

Returns the list of URL parameter scopes that are available for this resource. For example, if the resource accepted URLs like:

/api/resources/since/YYYY-MM-DD HH:MM:SS/outlet_id/abc-1234-def

this method would return [:since, :outlet_id]



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# File 'lib/vend/base.rb', line 61

def self.available_scopes
  @available_scopes ||= []
end

.build(client, attrs) ⇒ Object

Builds a new instance of the described resource using the specified attributes.



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# File 'lib/vend/base.rb', line 113

def self.build(client, attrs)
  self.new(client, :attrs => attrs)
end

.build_from_json(client, json) ⇒ Object

Builds a collection of instances from a JSON response



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# File 'lib/vend/base.rb', line 118

def self.build_from_json(client, json)
  json[collection_name].map do |attrs|
    self.build(client, attrs)
  end
end

.cast_attribute(attribute_name, type) ⇒ Object 



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# File 'lib/vend/base.rb', line 23

def self.cast_attribute(attribute_name, type)
  attribute_casts[attribute_name] = type
end

.collection_name ⇒ Object

Returns the endpoint name for a collection of this resource



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# File 'lib/vend/base.rb', line 37

def self.collection_name
  endpoint_name.pluralize
end

.default_collection_request_args ⇒ Object

Override this with arguments that are required on every collection request. I.e, to default to 500 items per page:

def default_collection_request_args
  super.merge(:url_params => {:page_size => 500})
end



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# File 'lib/vend/base.rb', line 157

def self.default_collection_request_args
  {}
end

.endpoint_name ⇒ Object

Returns the endpoint name for the resource, used in API urls when making requests.



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# File 'lib/vend/base.rb', line 32

def self.endpoint_name
  self.name.split('::').last.underscore
end

.find(client, id) ⇒ Object

Attempts to pull a singular object from Vend through the singular GET endpoint.



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# File 'lib/vend/base.rb', line 138

def self.find(client, id)
  response = client.request(singular_name(id))
  initialize_singular(client, response)
end

.findable_by(field, options = {}) ⇒ Object 



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# File 'lib/vend/base.rb', line 94

def self.findable_by(field, options = {})
  
  (class << self ; self ; end).instance_eval do
    define_method("find_by_#{field}") do |client, *args|
      search(client, options[:as] || field, *args)
    end
  end
end

.initialize_collection(client, endpoint, args = {}) ⇒ Object

Will initialize a collection of Resources from the APIs JSON Response.



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# File 'lib/vend/base.rb', line 131

def self.initialize_collection(client, endpoint, args = {})
  ResourceCollection.new(client, self, endpoint, args)
end

.initialize_singular(client, json) ⇒ Object

Initializes a single object from a JSON response. Assumes the response is a JSON array with a single item.



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# File 'lib/vend/base.rb', line 126

def self.initialize_singular(client, json)
  self.build(client, json[collection_name].first)
end

.paginates? ⇒ Boolean

Whether or not this resource can be paginated, false by default. Override this method in specific classes to enable pagination for that resource.

Returns:

  • (Boolean) 


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# File 'lib/vend/base.rb', line 146

def self.paginates?
  false
end

.search(client, field, query) ⇒ Object

Sends a search request to the API and initializes a collection of Resources from the response. This method is only used internally by find_by_field methods.



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# File 'lib/vend/base.rb', line 105

def self.search(client, field, query)
  initialize_collection(
    client, collection_name,  :url_params => { field.to_sym => query }
  )
end

.singular_name(id) ⇒ Object 



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# File 'lib/vend/base.rb', line 45

def self.singular_name(id)
  "#{collection_name}/#{id}"
end

.url_scope(method_name) ⇒ Object

Creates a class method that allows access to a filtered collection of resources on the API. For example:

class MyResource << Vend::Base
  url_scope :since
end

Will create a class method:

client.MyResource.since(argument)

That will call the following URL on the Vend API:

/api/my_resources/since/:argument

And return the corresponding collection of resources



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# File 'lib/vend/base.rb', line 85

def self.url_scope(method_name)
  (class << self ; self ; end).instance_eval do
    define_method(method_name) do |client, arg|
      initialize_collection(client, collection_name).scope(method_name, arg)
    end
  end
  available_scopes << method_name
end

Instance Method Details

#delete ⇒ Object

Attempts to delete the resource. If an exception is thrown by delete!, it is caught and false is returned (typically when the resource is not a type which can be deleted).



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# File 'lib/vend/base.rb', line 184

def delete
  delete!
rescue Vend::Resource::IllegalAction
  false
end

#delete! ⇒ Object

Attempts to delete there resource. Will throw an exception when the attempt fails, otherwise will return true.

Raises:



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# File 'lib/vend/base.rb', line 192

def delete!
  raise(Vend::Resource::IllegalAction,
        "#{self.class.name} has no unique ID") unless attrs['id']
  client.request(singular_name, :method => :delete)
  true
end

#respond_to?(method_name) ⇒ Boolean

Overrides respond_to? to query the attrs hash for the key before proxying it to the object

Returns:

  • (Boolean) 


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# File 'lib/vend/base.rb', line 163

def respond_to?(method_name)
  if attrs.keys.include? method_name.to_s
    true
  else
    super(method_name)
  end
end

#singular_name ⇒ Object 



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# File 'lib/vend/base.rb', line 41

def singular_name
  self.class.singular_name(id)
end