class Grape::API
The API class is the primary entry point for creating Grape APIs. Users should subclass this class in order to build an API.
Constants
- Boolean
- LOCK
A class-level lock to ensure the API is not compiled by multiple threads simultaneously within the same process.
Attributes
Public Class Methods
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.
# File lib/grape/api.rb, line 38 def call(env) LOCK.synchronize { compile } unless instance call!(env) end
A non-synchronized version of ::call.
# File lib/grape/api.rb, line 44 def call!(env) instance.call(env) end
(see cascade?)
# File lib/grape/api.rb, line 49 def cascade(value = nil) if value.nil? inheritable_setting.namespace_inheritable.keys.include?(:cascade) ? !namespace_inheritable(:cascade).nil? : true else namespace_inheritable(:cascade, value) end end
Wipe the compiled API so we can recompile after changes were made.
# File lib/grape/api.rb, line 30 def change! @instance = nil end
Parses the API's definition and compiles it into an instance of Grape::API.
# File lib/grape/api.rb, line 25 def compile @instance ||= new end
Builds the routes from the defined endpoints, effectively compiling this API into a usable form.
# File lib/grape/api.rb, line 106 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
see Grape::Router#recognize_path
# File lib/grape/api.rb, line 58 def recognize_path(path) LOCK.synchronize { compile } unless instance instance.router.recognize_path(path) end
Clears all defined routes, endpoints, etc., on this API.
# File lib/grape/api.rb, line 17 def reset! reset_endpoints! reset_routes! reset_validations! end
Protected Class Methods
# File lib/grape/api.rb, line 88 def inherit_settings(other_settings) top_level_setting.inherit_from other_settings.point_in_time_copy # Propagate any inherited params down to our endpoints, and reset any # compiled routes. endpoints.each do |e| e.inherit_settings(top_level_setting.namespace_stackable) e.reset_routes! end reset_routes! end
# File lib/grape/api.rb, line 83 def inherited(subclass) subclass.reset! subclass.logger = logger.clone end
Execute first the provided block, then each of the block passed in. Allows for simple 'before' setups of settings stack pushes.
# File lib/grape/api.rb, line 72 def nest(*blocks, &block) blocks.reject!(&:nil?) if blocks.any? instance_eval(&block) if block_given? blocks.each { |b| instance_eval(&b) } reset_validations! else instance_eval(&block) end end
# File lib/grape/api.rb, line 65 def prepare_routes endpoints.map(&:routes).flatten end
Public Instance Methods
Handle a request. See Rack documentation for what `env` is.
# File lib/grape/api.rb, line 118 def call(env) result = @router.call(env) result[1].delete(Grape::Http::Headers::X_CASCADE) unless cascade? result end
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.
# File lib/grape/api.rb, line 132 def cascade? return self.class.namespace_inheritable(:cascade) if self.class.inheritable_setting.namespace_inheritable.keys.include?(:cascade) return self.class.namespace_inheritable(:version_options)[:cascade] if self.class.namespace_inheritable(:version_options) && self.class.namespace_inheritable(:version_options).key?(:cascade) true end
Private Instance Methods
For every resource add a 'OPTIONS' route that returns an HTTP 204 response with a list of HTTP methods that can be called. Also add a route that will return an HTTP 405 response for any HTTP method that the resource cannot handle.
# File lib/grape/api.rb, line 146 def add_head_not_allowed_methods_and_options_methods routes_map = {} self.class.endpoints.each do |endpoint| routes = endpoint.routes routes.each do |route| # using the :any shorthand produces [nil] for route methods, substitute all manually route_key = route.pattern.to_regexp routes_map[route_key] ||= {} route_settings = routes_map[route_key] route_settings[:pattern] = route.pattern route_settings[:requirements] = route.requirements route_settings[:path] = route.origin route_settings[:methods] ||= [] route_settings[:methods] << route.request_method route_settings[:endpoint] = route.app # using the :any shorthand produces [nil] for route methods, substitute all manually route_settings[:methods] = %w[GET PUT POST DELETE PATCH HEAD OPTIONS] if route_settings[:methods].include?('*') end end # The paths we collected are prepared (cf. Path#prepare), so they # contain already versioning information when using path versioning. # Disable versioning so adding a route won't prepend versioning # informations again. without_root_prefix do without_versioning do routes_map.each do |_, config| methods = config[:methods] allowed_methods = methods.dup unless self.class.namespace_inheritable(:do_not_route_head) allowed_methods |= [Grape::Http::Headers::HEAD] if allowed_methods.include?(Grape::Http::Headers::GET) end allow_header = (self.class.namespace_inheritable(:do_not_route_options) ? allowed_methods : [Grape::Http::Headers::OPTIONS] | allowed_methods).join(', ') unless self.class.namespace_inheritable(:do_not_route_options) || allowed_methods.include?(Grape::Http::Headers::OPTIONS) config[:endpoint].options[:options_route_enabled] = true end attributes = config.merge(allowed_methods: allowed_methods, allow_header: allow_header) generate_not_allowed_method(config[:pattern], attributes) end end end end
Generate a route that returns an HTTP 405 response for a user defined path on methods not specified
# File lib/grape/api.rb, line 197 def generate_not_allowed_method(pattern, allowed_methods: [], **attributes) not_allowed_methods = %w[GET PUT POST DELETE PATCH HEAD] - allowed_methods not_allowed_methods << Grape::Http::Headers::OPTIONS if self.class.namespace_inheritable(:do_not_route_options) return if not_allowed_methods.empty? @router.associate_routes(pattern, not_allowed_methods: not_allowed_methods, **attributes) end
Allows definition of endpoints that ignore the root prefix used by the rest of your API.
# File lib/grape/api.rb, line 223 def without_root_prefix(&_block) old_prefix = self.class.namespace_inheritable(:root_prefix) self.class.namespace_inheritable_to_nil(:root_prefix) yield self.class.namespace_inheritable(:root_prefix, old_prefix) end
Allows definition of endpoints that ignore the versioning configuration used by the rest of your API.
# File lib/grape/api.rb, line 208 def without_versioning(&_block) old_version = self.class.namespace_inheritable(:version) old_version_options = self.class.namespace_inheritable(:version_options) self.class.namespace_inheritable_to_nil(:version) self.class.namespace_inheritable_to_nil(:version_options) yield self.class.namespace_inheritable(:version, old_version) self.class.namespace_inheritable(:version_options, old_version_options) end