module Roda::RodaPlugins::HashBranches

The hash_branches plugin allows for O(1) dispatch to multiple route tree branches, based on the next segment in the remaining path:

class App < Roda
  plugin :hash_branches

  hash_branch("a") do |r|
    # /a branch
  end

  hash_branch("b") do |r|
    # /b branch
  end

  route do |r|
    r.hash_branches
  end
end

With the above routing tree, the r.hash_branches call in the main routing tree will dispatch requests for the /a and /b branches of the tree to the appropriate routing blocks.

In this example, the hash branches for /a and /b are in the same file, but in larger applications, they are usually stored in separate files. This allows for easily splitting up the routing tree into a separate file per branch.

The hash_branch method supports namespaces, which allow for dispatching to sub-branches any level of the routing tree, fully supporting the needs of applications with large and deep routing branches:

class App < Roda
  plugin :hash_branches

  # Only one argument used, so the namespace defaults to '', and the argument
  # specifies the route name
  hash_branch("a") do |r|
    # No argument given, so uses the already matched path as the namespace,
    # which is '/a' in this case.
    r.hash_branches
  end

  hash_branch("b") do |r|
    # uses :b as the namespace when looking up routes, as that was explicitly specified
    r.hash_branches(:b)
  end

  # Two arguments used, so first specifies the namespace and the second specifies
  # the branch name
  hash_branch("/a", "b") do |r|
    # /a/b path
  end

  hash_branch("/a", "c") do |r|
    # /a/c path
  end

  hash_branch(:b, "b") do |r|
    # /b/b path
  end

  hash_branch(:b, "c") do |r|
    # /b/c path
  end

  route do |r|
    # No argument given, so uses '' as the namespace, as no part of the path has
    # been matched yet
    r.hash_branches
  end
end

With the above routing tree, requests for the /a and /b branches will be dispatched to the appropriate hash_branch block. Those blocks will the dispatch to the remaining hash_branch blocks, with the /a branch using the implicit namespace of /a, and the /b branch using the explicit namespace of :b.

It is best for performance to explicitly specify the namespace when calling r.hash_branches.

Methods

Public Class

1. configure

Classes and Modules

1. Roda::RodaPlugins::HashBranches::ClassMethods
2. Roda::RodaPlugins::HashBranches::RequestMethods