Register an object that knows how to handle template files with the given
extensions.
This can be used to implement new template types. The handler must respond
to :call, which will be passed the template and should return the
rendered template as a String.
# File actionview/lib/action_view/template/handlers.rb, line 39
def register_template_handler(*extensions, handler)
params = if handler.is_a?(Proc)
handler.parameters
else
handler.method(:call).parameters
end
unless params.find_all { |type, _| type == :req || type == :opt }.length >= 2
ActiveSupport::Deprecation.warn <<~eowarn
Single arity template handlers are deprecated. Template handlers must
now accept two parameters, the view object and the source for the view object.
Change:
>> #{handler}.call(#{params.map(&:last).join(", ")})
To:
>> #{handler}.call(#{params.map(&:last).join(", ")}, source)
eowarn
handler = LegacyHandlerWrapper.new(handler)
end
raise(ArgumentError, "Extension is required") if extensions.empty?
extensions.each do |extension|
@@template_handlers[extension.to_sym] = handler
end
@@template_extensions = nil
end
# Opposite to register_template_handler.
def unregister_template_handler(*extensions)
extensions.each do |extension|
handler = @@template_handlers.delete extension.to_sym
@@default_template_handlers = nil if @@default_template_handlers == handler
end
@@template_extensions = nil
end
def template_handler_extensions
@@template_handlers.keys.map(&:to_s).sort
end
def registered_template_handler(extension)
extension && @@template_handlers[extension.to_sym]
end
def register_default_template_handler(extension, klass)
register_template_handler(extension, klass)
@@default_template_handlers = klass
end
def handler_for_extension(extension)
registered_template_handler(extension) || @@default_template_handlers
end
end