Class: Grape::API::Instance

Inherits:
Object
  • Object
show all
Includes:
DSL::API
Defined in:
lib/grape/api/instance.rb,
lib/grape/api.rb

Overview

The API Instance class, is the engine behind Grape::API. Each class that inherits from this will represent a different API instance

Constant Summary collapse

Boolean = 
Grape::API::Boolean
LOCK =

A class-level lock to ensure the API is not compiled by multiple threads simultaneously within the same process.

Mutex.new

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Instance

Builds the routes from the defined endpoints, effectively compiling this API into a usable form.



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# File 'lib/grape/api/instance.rb', line 151

def initialize
  @router = Router.new
  add_head_not_allowed_methods_and_options_methods
  self.class.endpoints.each do |endpoint|
    endpoint.mount_in(@router)
  end

  @router.compile!
  @router.freeze
end

Class Attribute Details

.base ⇒ Object

Returns the value of attribute base.



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# File 'lib/grape/api/instance.rb', line 11

def base
  @base
end

.configuration ⇒ Object

Returns the value of attribute configuration.



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# File 'lib/grape/api/instance.rb', line 12

def configuration
  @configuration
end

.instance ⇒ Object (readonly)

Returns the value of attribute instance.



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# File 'lib/grape/api/instance.rb', line 11

def instance
  @instance
end

Instance Attribute Details

#router ⇒ Object (readonly)

Returns the value of attribute router.



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# File 'lib/grape/api/instance.rb', line 147

def router
  @router
end

Class Method Details

.base_instance? ⇒ Boolean

Returns:



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# File 'lib/grape/api/instance.rb', line 31

def base_instance?
  self == base.base_instance
end

.call(env) ⇒ Object

This is the interface point between Rack and Grape; it accepts a request from Rack and ultimately returns an array of three values: the status, the headers, and the body. See [the rack specification] (www.rubydoc.info/github/rack/rack/master/file/SPEC) for more.



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# File 'lib/grape/api/instance.rb', line 61

def call(env)
  compile!
  call!(env)
end

.call!(env) ⇒ Object

A non-synchronized version of ::call.



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# File 'lib/grape/api/instance.rb', line 67

def call!(env)
  instance.call(env)
end

.cascade(value = nil) ⇒ Object

Some requests may return a HTTP 404 error if grape cannot find a matching route. In this case, Grape::Router adds a X-Cascade header to the response and sets it to ‘pass’, indicating to grape’s parents they should keep looking for a matching route on other resources.

In some applications (e.g. mounting grape on rails), one might need to trap errors from reaching upstream. This is effectivelly done by unsetting X-Cascade. Default :cascade is true.



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# File 'lib/grape/api/instance.rb', line 72

def cascade(value = nil)
  if value.nil?
    inheritable_setting.namespace_inheritable.key?(:cascade) ? !namespace_inheritable(:cascade).nil? : true
  else
    namespace_inheritable(:cascade, value)
  end
end

.change! ⇒ Object

Wipe the compiled API so we can recompile after changes were made.



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# File 'lib/grape/api/instance.rb', line 53

def change!
  @instance = nil
end

.compile ⇒ Object

Parses the API’s definition and compiles it into an instance of Grape::API.



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# File 'lib/grape/api/instance.rb', line 48

def compile
  @instance ||= new # rubocop:disable Naming/MemoizedInstanceVariableName
end

.compile! ⇒ Object 



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# File 'lib/grape/api/instance.rb', line 80

def compile!
  return if instance

  LOCK.synchronize { compile unless instance }
end

.given(conditional_option, &block) ⇒ Object 



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# File 'lib/grape/api/instance.rb', line 14

def given(conditional_option, &block)
  evaluate_as_instance_with_configuration(block, lazy: true) if conditional_option && block
end

.mounted(&block) ⇒ Object 



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# File 'lib/grape/api/instance.rb', line 18

def mounted(&block)
  evaluate_as_instance_with_configuration(block, lazy: true)
end

.recognize_path(path) ⇒ Object

see Grape::Router#recognize_path



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# File 'lib/grape/api/instance.rb', line 87

def recognize_path(path)
  compile!
  instance.router.recognize_path(path)
end

.reset! ⇒ Object

Clears all defined routes, endpoints, etc., on this API.



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# File 'lib/grape/api/instance.rb', line 40

def reset!
  reset_endpoints!
  reset_routes!
  reset_validations!
end

.to_s ⇒ Object 



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# File 'lib/grape/api/instance.rb', line 27

def to_s
  base&.to_s || super
end

Instance Method Details

#call(env) ⇒ Object

Handle a request. See Rack documentation for what ‘env` is.



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# File 'lib/grape/api/instance.rb', line 163

def call(env)
  status, headers, response = @router.call(env)
  unless cascade?
    headers = Grape::Util::Header.new.merge(headers)
    headers.delete(Grape::Http::Headers::X_CASCADE)
  end

  [status, headers, response]
end

#cascade? ⇒ Boolean

Some requests may return a HTTP 404 error if grape cannot find a matching route. In this case, Grape::Router adds a X-Cascade header to the response and sets it to ‘pass’, indicating to grape’s parents they should keep looking for a matching route on other resources.

In some applications (e.g. mounting grape on rails), one might need to trap errors from reaching upstream. This is effectivelly done by unsetting X-Cascade. Default :cascade is true.

Returns:



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# File 'lib/grape/api/instance.rb', line 181

def cascade?
  return self.class.namespace_inheritable(:cascade) if self.class.inheritable_setting.namespace_inheritable.key?(:cascade)
  return self.class.namespace_inheritable(:version_options)[:cascade] if self.class.namespace_inheritable(:version_options)&.key?(:cascade)

  true
end