Module: Roda::RodaPlugins::HostRouting

Defined in:
lib/roda/plugins/host_routing.rb

Overview

The host_routing plugin adds support for more routing requests based on the requested host. It also adds predicate methods for checking whether a request was requested with the given host.

When loading the plugin, you pass a block, which is used for configuring the plugin. For example, if you want to treat requests to api.example.com or api2.example.com as api requests, and treat other requests as www requests, you could use:

plugin :host_routing do |hosts|
  hosts.to :api, "api.example.com", "api2.example.com"
  hosts.default :www
end

With this configuration, in your routing tree, you can call the r.api and r.www methods for dispatching to routing blocks only for those types of requests:

route do |r|
  r.api do
    # requests to api.example.com or api2.example.com
  end

  r.www do
    # requests to other domains
  end
end

In addition to the routing methods, predicate methods are also added to the request object:

route do |r|
  "#{r.api?}-#{r.www?}"
end
# Requests to api.example.com or api2.example.com return "true-false"
# Other requests return "false-true"

If the :scope_predicates plugin option is given, predicate methods are also created in route block scope:

plugin :host_routing, scope_predicates: true do |hosts|
  hosts.to :api, "api.example.com"
  hosts.default :www
end

route do |r|
  "#{api?}-#{www?}"
end

To handle hosts that match a certain format (such as all subdomains), where the specific host names are not known up front, you can provide a block when calling hosts.default. This block is passed the host name, or an empty string if no host name is provided, and is evaluated in route block scope. When using this support, you should also call hosts.register to register host types that could be returned by the block. For example, to handle api subdomains differently:

plugin :host_routing do |hosts|
  hosts.to :api, "api.example.com"
  hosts.register :api_sub
  hosts.default :www do |host|
    :api_sub if host.end_with?(".api.example.com")
  end
end

This plugin uses the host method on the request to get the hostname (this method is defined by Rack).

Defined Under Namespace

Modules: InstanceMethods, RequestMethods

Class Method Summary collapse

Class Method Details

.configure(app, opts = OPTS, &block) ⇒ Object

Setup the host routing support. The block yields an object used to configure the plugin. Options:

:scope_predicates

Setup predicate methods in route block scope in addition to request scope.



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# File 'lib/roda/plugins/host_routing.rb', line 79

def self.configure(app, opts=OPTS, &block)
  hosts, host_hash, default_block, default_host = DSL.new.process(&block)
  app.opts[:host_routing_hash] = host_hash
  app.opts[:host_routing_default_host] = default_host

  app.send(:define_method, :_host_routing_default, &default_block) if default_block

  app::RodaRequest.class_exec do
    hosts.each do |host|
      host_sym = host.to_sym
      define_method(host_sym){|&blk| always(&blk) if _host_routing_host == host}
      alias_method host_sym, host_sym

      meth = :"#{host}?"
      define_method(meth){_host_routing_host == host}
      alias_method meth, meth
    end
  end

  if opts[:scope_predicates]
    app.class_exec do
      hosts.each do |host|
        meth = :"#{host}?"
        define_method(meth){@_request.send(meth)}
        alias_method meth, meth
      end
    end
  end
end