# Inch CI

Register a block as simple hash transformation that runs before expanding the pattern.
@return [Mustermann::Expander] the expander

@overload cast
  Register a block as simple hash transformation that runs before expanding the pattern for all entries.

  @example casting everything that implements to_param to param
    expander.cast { |o| o.to_param if o.respond_to? :to_param }

  @yield every key/value pair
  @yieldparam key [Symbol] omitted if block takes less than 2
  @yieldparam value [Object] omitted if block takes no arguments
  @yieldreturn [Hash{Symbol: Object}] will replace key/value pair with returned hash
  @yieldreturn [nil, false] will keep key/value pair in hash
  @yieldreturn [Object] will replace value with returned object

@overload cast(*type_matchers)
  Register a block as simple hash transformation that runs before expanding the pattern for certain entries.

  @example convert user to user_id
    expander = Mustermann::Expander.new('/users/:user_id')
    expand.cast(:user) { |user| { user_id: user.id } }

    expand.expand(user: User.current) # => "/users/42"

  @example convert user, page, image to user_id, page_id, image_id
    expander = Mustermann::Expander.new('/users/:user_id', '/pages/:page_id', '/:image_id.jpg')
    expand.cast(:user, :page, :image) { |key, value| { "#{key}_id".to_sym => value.id } }

    expand.expand(user: User.current) # => "/users/42"

  @example casting to multiple key/value pairs
    expander = Mustermann::Expander.new('/users/:user_id/:image_id.:format')
    expander.cast(:image) { |i| { user_id: i.owner.id, image_id: i.id, format: i.format } }

    expander.expander(image: User.current.avatar) # => "/users/42/avatar.jpg"

  @example casting all ActiveRecord objects to param
    expander.cast(ActiveRecord::Base, &:to_param)

  @param [Array<Symbol, Regexp, #===>] type_matchers
    To identify key/value pairs to match against.
    Regexps and Symbols match against key, everything else matches against value.

  @yield every key/value pair
  @yieldparam key [Symbol] omitted if block takes less than 2
  @yieldparam value [Object] omitted if block takes no arguments
  @yieldreturn [Hash{Symbol: Object}] will replace key/value pair with returned hash
  @yieldreturn [nil, false] will keep key/value pair in hash
  @yieldreturn [Object] will replace value with returned object

@overload cast(*cast_objects)

  @param [Array<#cast>] cast_objects
    Before expanding, will call #cast on these objects for each key/value pair.
    Return value will be treated same as block return values described above.