Class: Merb::Router

Inherits:
Object show all
Defined in:
lib/merb-core/dispatch/router.rb,
lib/merb-core/dispatch/router/route.rb,
lib/merb-core/dispatch/router/behavior.rb,
lib/merb-core/dispatch/router/resources.rb,
lib/merb-core/dispatch/router/cached_proc.rb

Overview

Router stores route definitions and finds the first route that matches the incoming request URL.

Then information from route is used by dispatcher to call action on the controller.

Routes compilation.

The most interesting method of Router (and heart of route matching machinery) is match method generated on the fly from routes definitions. It is called routes compilation. Generated match method body contains one if/elsif statement that picks the first matching route definition and sets values to named parameters of the route.

Compilation is synchronized by mutex.

Defined Under Namespace

Modules: Resources Classes: Behavior, CachedProc, GenerationError, NotCompiledError, ResourceBehavior, Route, RouteNotFound

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.around_matchObject

A block that will be run around route matching. This block must yield in order for the actual matching to happen.

:api: plugin


84
85
86
# File 'lib/merb-core/dispatch/router.rb', line 84

def around_match
  @around_match
end

.named_routesObject

A hash containing all the named application routes. The names are absolute (as in, all routes named in a namespace will contain the name of the namespace).

:api: private


49
50
51
# File 'lib/merb-core/dispatch/router.rb', line 49

def named_routes
  @named_routes
end

.resource_routesObject

A hash of all the application resource routes. The key of the hash is an array with each element containing the “path” for the resource for example, given the following resource routes:

resources :users do

resources :comments

end

The show comment route will have a key of [“User”, “Comment”]

:api: private


62
63
64
# File 'lib/merb-core/dispatch/router.rb', line 62

def resource_routes
  @resource_routes
end

.root_behaviorObject

The starting point for route definition. Any route defined in a Merb::Router.prepare block will defined in context of this behavior.

Examples

Merb::Router.root_behavior = Merb::Router.root_bavior.match(“/hello”)

In the previous example, all routes will have the path prefix /hello. It is important to note that this attribute must be set before any routes are defined in order for the behavior to be applied to the routes.

:api: plugin


78
79
80
# File 'lib/merb-core/dispatch/router.rb', line 78

def root_behavior
  @root_behavior
end

.routesObject

An array containing all the application routes in order of priority.

:api: private


42
43
44
# File 'lib/merb-core/dispatch/router.rb', line 42

def routes
  @routes
end

Class Method Details

.extensions(&block) ⇒ Object

Add functionality to the router. This can be in the form of including a new module or directly defining new methods.

Parameters

&block<Block>

A block of code used to extend the route builder with. This can be including a module or directly defining some new methods that should be available to building routes.

Returns

nil

Example

Merb::Router.extensions do
  def domain(name, domain, options={}, &block)
    match(:domain => domain).namespace(name, :path => nil, &block)
  end
end

In this case, a method 'domain' will be available to the route builder which will create namespaces around domains instead of path prefixes.

This can then be used as follows.

Merb::Router.prepare do
  domain(:admin, "my-admin.com") do
    # ... routes come here ...
  end
end

:api: public


310
311
312
# File 'lib/merb-core/dispatch/router.rb', line 310

def extensions(&block)
  Router::Behavior.class_eval(&block)
end

.match_before_compilation(request) ⇒ Object Also known as: match

A placeholder for the compiled match method.

Notes

This method is aliased as match but this method gets overridden with the actual match method (generated from the routes definitions) after being compiled. This method is only ever called before routes are compiled.

Raises

NotCompiledError

routes have not been compiled yet.

:api: private

Raises:


161
162
163
# File 'lib/merb-core/dispatch/router.rb', line 161

def match_before_compilation(request) #:nodoc:
  raise NotCompiledError, "The routes have not been compiled yet"
end

.prepare(first = [], last = [], &block) ⇒ Object

Creates a route building context and evaluates the block in it. A copy of root_behavior (and instance of Behavior) is copied as the context.

Parameters

first<Array>

An array containing routes that should be prepended to the routes defined in the block.

last<Array>

An array containing routes that should be appended to the routes defined in the block.

Returns

Merb::Router

Returns self to allow chaining of methods.

:api: public


103
104
105
106
107
108
109
# File 'lib/merb-core/dispatch/router.rb', line 103

def prepare(first = [], last = [], &block)
  @routes = []
  root_behavior._with_proxy(&block)
  @routes = first + @routes + last
  compile
  self
end

.reset!Object

Clears the routing table. Route generation and request matching won't work anymore until a new routing table is built.

:api: private


115
116
117
118
119
120
# File 'lib/merb-core/dispatch/router.rb', line 115

def reset!
  class << self
    alias_method :match, :match_before_compilation
  end
  self.routes, self.named_routes, self.resource_routes = [], {}, {}
end

.resource(*args) ⇒ Object

Generates a URL from the resource(s)

Parameters

resources<Symbol,Object>

The identifiers for the resource route to generate. These can either be symbols or objects. Symbols denote resource collection routes and objects denote the members.

params<Hash>

Any extra parameters needed to generate the route.

Returns

String

The generated URL

:api: plugin


255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
# File 'lib/merb-core/dispatch/router.rb', line 255

def resource(*args)
  defaults = args.pop
  options  = extract_options_from_args!(args) || {}
  key      = []
  params   = []
  
  args.each do |arg|
    if arg.is_a?(Symbol) || arg.is_a?(String)
      key << arg.to_s
    else
      key << arg.class.to_s
      params << arg
    end
  end
  
  unless route = Merb::Router.resource_routes[key]
    raise Merb::Router::GenerationError, "Resource route not found: #{args.inspect}"
  end

  params << options
  
  route.generate(params, defaults, true)
end

.route_for(request) ⇒ Object

Finds route matching URI of the request and returns a tuple of [route index, route params]. This method is called by the dispatcher and isn't as useful in applications.

Parameters

request<Merb::Request>

request to match.

Returns

Array[Integer, Hash]

Two-tuple: route index and route parameters. Route parameters are :controller, :action and all the named segments of the route.

:api: private


135
136
137
138
139
140
141
142
143
144
145
146
147
# File 'lib/merb-core/dispatch/router.rb', line 135

def route_for(request)
  index, params = if @around_match
    send(@around_match, request) { match(request) }
  else
    match(request)
  end
  route = routes[index] if index
  if !route
    raise ControllerExceptions::NotFound, 
      "No routes match the request: #{request.uri}"
  end
  [route, params]
end

.url(name, *args) ⇒ Object

There are three possible ways to use this method. First, if you have a named route, you can specify the route as the first parameter as a symbol and any paramters in a hash. Second, you can generate the default route by just passing the params hash, just passing the params hash. Finally, you can use the anonymous parameters. This allows you to specify the parameters to a named route in the order they appear in the router.

Parameters(Named Route)

name<Symbol>

The name of the route.

args<Hash>

Parameters for the route generation.

Parameters(Default Route)

args<Hash>

Parameters for the route generation. This route will use the default route.

Parameters(Anonymous Parameters)

name<Symbol>

The name of the route.

args<Array>

An array of anonymous parameters to generate the route with. These parameters are assigned to the route parameters in the order that they are passed.

Returns

String

The generated URL.

Examples

Named Route

Merb::Router.prepare do

match("/articles/:title").to(:controller => :articles, :action => :show).name("articles")

end

url(:articles, :title => “new_article”)

Default Route

Merb::Router.prepare do

default_routes

end

url(:controller => “articles”, :action => “new”)

Anonymous Paramters

Merb::Router.prepare do

match("/articles/:year/:month/:title").to(:controller => :articles, :action => :show).name("articles")

end

url(:articles, 2008, 10, “test_article”)

:api: plugin


221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
# File 'lib/merb-core/dispatch/router.rb', line 221

def url(name, *args)
  if name.is_a?(Route)
    route = name
  else
    unless name.is_a?(Symbol)
      args.unshift(name)
      name = :default
    end

    unless route = Merb::Router.named_routes[name]
      raise Merb::Router::GenerationError, "Named route not found: #{name}"
    end
  end
  
  defaults = args.pop
  
  route.generate(args, defaults)
end