require 'lotus/view/rendering/registry' require 'lotus/view/rendering/scope' module Lotus module View # Rendering methods # # @since 0.1.0 # # @see Lotus::View::Rendering::InstanceMethods module Rendering def self.extended(base) base.class_eval do include InstanceMethods end end module InstanceMethods # Initialize a view # # @param template [Lotus::View::Template] the template to render # @param locals [Hash] a set of objects available during the rendering # process. # # @since 0.1.0 # # @see Lotus::View::Template # # @example # require 'lotus/view' # # class IndexView # include Lotus::View # end # # template = Lotus::View::Template.new('index.html.erb') # view = IndexView.new(template, {article: article}) def initialize(template, locals) @template = template @locals = locals @scope = Scope.new(self, @locals) end # Render the template by bounding the local scope. # If it uses a layout, it renders the template first and then the # control passes to the layout. # # Override this method for custom rendering policies. # For instance, when a serializer is used and there isn't the need of # a template. # # @return [String] the output of the rendering process # # @raise [Lotus::View::MissingTemplateError] if the template is nil # # @since 0.1.0 # # @see Lotus::View::Layout # # @example with template # require 'lotus/view' # # class IndexView # include Lotus::View # end # # template = Lotus::View::Template.new('index.html.erb') # view = IndexView.new(template, {article: article}) # # view.render # => <h1>Introducing Lotus::view</h1> ... # # @example with template and layout # require 'lotus/view' # # class ApplicationLayout # include Lotus::View::Layout # end # # class IndexView # include Lotus::View # layout :application # end # # template = Lotus::View::Template.new('index.html.erb') # view = IndexView.new(template, {article: article}) # # view.render # => <html> ... <h1>Introducing Lotus::view</h1> ... # # @example with custom rendering # require 'lotus/view' # # class IndexView # include Lotus::View # # def render # ArticleSerializer.new(article).render # end # end # # view = IndexView.new(nil, {article: article}) # # view.render # => {title: ...} def render layout.render end protected # The output of the template rendering process. # # @return [String] the rendering output # # @raise [Lotus::View::MissingTemplateError] if the template is nil # # @api private # @since 0.1.0 def rendered template.render @scope end # The layout. # # @return [Class, Lotus::View::Rendering::NullLayout] # # @see Lotus::View::Layout # @see Lotus::View.layout # @see Lotus::View::Dsl#layout # # @api private # @since 0.1.0 def layout @layout ||= self.class.layout.new(@scope, rendered) end # The template. # # @return [Lotus::View::Template] the template # # @raise [Lotus::View::MissingTemplateError] if the template is nil # # @api private # @since 0.1.0 def template @template or raise MissingTemplateError.new(self.class.template, @scope.format) end # A set of objects available during the rendering process. # # @return [Hash] # # @see Lotus::View#initialize # # @api private # @since 0.1.0 def locals @locals end # Delegates missing methods to the scope. # # @see Lotus::View::Rendering::Scope # # @api private # @since 0.1.0 # # @example # require 'lotus/view' # # class IndexView # include Lotus::View # end # # template = Lotus::View::Template.new('index.html.erb') # view = IndexView.new(template, {article: article}) # # view.article # => #<Article:0x007fb0bbd3b6e8> def method_missing(m) @scope.__send__ m end end # Render the given context and locals with the appropriate template. # If there are registered subclasses, it choose the right class, according # to the requested format. # # @param context [Hash] the context for the rendering process # @option context [Symbol] :format the requested format # # @return [String] the output of the rendering process # # @raise [Lotus::View::MissingTemplateError] if it can't find a template # for the given context # # @raise [Lotus::View::MissingFormatError] if the given context doesn't # have the :format key # # @since 0.1.0 # # @see Lotus::View#initialize # @see Lotus::View#render # # @example # require 'lotus/view' # # article = OpenStruct.new(title: 'Hello') # # module Articles # class Show # include Lotus::View # # def title # @title ||= article.title.upcase # end # end # # class JsonShow < Show # format :json # # def title # super.downcase # end # end # end # # Lotus::View.root = '/path/to/templates' # Lotus::View.load! # # Articles::Show.render(format: :html, article: article) # # => renders `articles/show.html.erb` # # Articles::Show.render(format: :json, article: article) # # => renders `articles/show.json.erb` # # Articles::Show.render(format: :xml, article: article) # # => raises Lotus::View::MissingTemplateError def render(context) registry.resolve(context).render end protected # Loading mechanism hook. # # @api private # @since 0.1.0 # # @see Lotus::View.load! def load! super registry.freeze end private # The registry that holds all the registered subclasses. # # @api private # @since 0.1.0 # # @see Lotus::View::Rendering::Registry def registry @@registry ||= Registry.new(self) end end end end