module ViewComponent::SlotableV2
Public Instance Methods
get_slot(slot_name)
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# File lib/view_component/slotable_v2.rb, line 221 def get_slot(slot_name) content unless content_evaluated? # ensure content is loaded so slots will be defined slot = self.class.registered_slots[slot_name] @__vc_set_slots ||= {} if @__vc_set_slots[slot_name] return @__vc_set_slots[slot_name] end if slot[:collection] [] else nil end end
inherited(child)
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Clone slot configuration into child class see test_slots_pollution
Calls superclass method
# File lib/view_component/slotable_v2.rb, line 158 def inherited(child) child.registered_slots = self.registered_slots.clone super end
raise_if_slot_registered(slot_name)
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# File lib/view_component/slotable_v2.rb, line 210 def raise_if_slot_registered(slot_name) if self.registered_slots.key?(slot_name) # TODO remove? This breaks overriding slots when slots are inherited raise ArgumentError.new( "#{self} declares the #{slot_name} slot multiple times.\n\n" \ "To fix this issue, choose a different slot name." ) end end
register_slot(slot_name, collection:, callable:)
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# File lib/view_component/slotable_v2.rb, line 165 def register_slot(slot_name, collection:, callable:) # Setup basic slot data slot = { collection: collection, } # If callable responds to `render_in`, we set it on the slot as a renderable if callable && callable.respond_to?(:method_defined?) && callable.method_defined?(:render_in) slot[:renderable] = callable elsif callable.is_a?(String) # If callable is a string, we assume it's referencing an internal class slot[:renderable_class_name] = callable elsif callable # If slot does not respond to `render_in`, we assume it's a proc, # define a method, and save a reference to it to call when setting method_name = :"_call_#{slot_name}" define_method method_name, &callable slot[:renderable_function] = instance_method(method_name) end # Register the slot on the component self.registered_slots[slot_name] = slot end
renders_many(slot_name, callable = nil)
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Registers a collection sub-component
Example¶ ↑
render_many :items, -> (name:) { ItemComponent.new(name: name } # OR render_many :items, ItemComponent
Rendering sub-components¶ ↑
The component's sidecar template can access the slot by calling a helper method with the same name as the slot.
<h1> <% items.each do |item| %> <%= item %> <% end %> </h1>
Setting sub-component content¶ ↑
Consumers of the component can set the content of a slot by calling a helper method with the same name as the slot. The method can be called multiple times to append to the slot.
<%= render_inline(MyComponent.new) do |component| %> <% component.item(name: "Foo") do %> <p>One</p> <% end %> <% component.item(name: "Bar") do %> <p>two</p> <% end %> <% end %>
# File lib/view_component/slotable_v2.rb, line 118 def renders_many(slot_name, callable = nil) validate_plural_slot_name(slot_name) singular_name = ActiveSupport::Inflector.singularize(slot_name) # Define setter for singular names # e.g. `renders_many :items` allows fetching all tabs with # `component.tabs` and setting a tab with `component.tab` define_method singular_name do |*args, **kwargs, &block| set_slot(slot_name, *args, **kwargs, &block) end # Instantiates and and adds multiple slots forwarding the first # argument to each slot constructor define_method slot_name do |collection_args = nil, &block| if collection_args.nil? && block.nil? get_slot(slot_name) else collection_args.map do |args| set_slot(slot_name, **args, &block) end end end register_slot(slot_name, collection: true, callable: callable) end
renders_one(slot_name, callable = nil)
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Registers a sub-component
Example¶ ↑
renders_one :header -> (classes:) do HeaderComponent.new(classes: classes) end # OR renders_one :header, HeaderComponent where `HeaderComponent` is defined as: class HeaderComponent < ViewComponent::Base def initialize(classes:) @classes = classes end end and has the following template: <header class="<%= @classes %>"> <%= content %> </header>
Rendering sub-component content¶ ↑
The component's sidecar template can access the sub-component by calling a helper method with the same name as the sub-component.
<h1> <%= header do %> My header title <% end %> </h1>
Setting sub-component content¶ ↑
Consumers of the component can render a sub-component by calling a helper method with the same name as the slot.
<%= render_inline(MyComponent.new) do |component| %> <% component.header(classes: "Foo") do %> <p>Bar</p> <% end %> <% end %>
# File lib/view_component/slotable_v2.rb, line 67 def renders_one(slot_name, callable = nil) validate_singular_slot_name(slot_name) define_method slot_name do |*args, **kwargs, &block| if args.empty? && kwargs.empty? && block.nil? get_slot(slot_name) else set_slot(slot_name, *args, **kwargs, &block) end end register_slot(slot_name, collection: false, callable: callable) end
set_slot(slot_name, *args, **kwargs, &block)
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# File lib/view_component/slotable_v2.rb, line 238 def set_slot(slot_name, *args, **kwargs, &block) slot_definition = self.class.registered_slots[slot_name] slot = SlotV2.new(self) # Passing the block to the sub-component wrapper like this has two # benefits: # # 1. If this is a `content_area` style sub-component, we will render the # block via the `slot` # # 2. Since we have to pass block content to components when calling # `render`, evaluating the block here would require us to call # `view_context.capture` twice, which is slower slot.__vc_content_block = block if block_given? # If class if slot_definition[:renderable] slot.__vc_component_instance = slot_definition[:renderable].new(*args, **kwargs) # If class name as a string elsif slot_definition[:renderable_class_name] slot.__vc_component_instance = self.class.const_get(slot_definition[:renderable_class_name]).new(*args, **kwargs) # If passed a lambda elsif slot_definition[:renderable_function] # Use `bind(self)` to ensure lambda is executed in the context of the # current component. This is necessary to allow the lambda to access helper # methods like `content_tag` as well as parent component state. renderable_value = if block_given? slot_definition[:renderable_function].bind(self).call(*args, **kwargs) do |*args, **kwargs| view_context.capture(*args, **kwargs, &block) end else slot_definition[:renderable_function].bind(self).call(*args, **kwargs) end # Function calls can return components, so if it's a component handle it specially if renderable_value.respond_to?(:render_in) slot.__vc_component_instance = renderable_value else slot.__vc_content = renderable_value end end @__vc_set_slots ||= {} if slot_definition[:collection] @__vc_set_slots[slot_name] ||= [] @__vc_set_slots[slot_name].push(slot) else @__vc_set_slots[slot_name] = slot end slot end
slot_type(slot_name)
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# File lib/view_component/slotable_v2.rb, line 145 def slot_type(slot_name) registered_slot = registered_slots[slot_name] if registered_slot registered_slot[:collection] ? :collection : :single else plural_slot_name = ActiveSupport::Inflector.pluralize(slot_name).to_sym plural_registered_slot = registered_slots[plural_slot_name] plural_registered_slot&.fetch(:collection) ? :collection_item : nil end end
validate_plural_slot_name(slot_name)
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# File lib/view_component/slotable_v2.rb, line 188 def validate_plural_slot_name(slot_name) if slot_name.to_sym == :contents raise ArgumentError.new( "#{self} declares a slot named #{slot_name}, which is a reserved word in the ViewComponent framework.\n\n" \ "To fix this issue, choose a different name." ) end raise_if_slot_registered(slot_name) end
validate_singular_slot_name(slot_name)
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# File lib/view_component/slotable_v2.rb, line 199 def validate_singular_slot_name(slot_name) if slot_name.to_sym == :content raise ArgumentError.new( "#{self} declares a slot named #{slot_name}, which is a reserved word in the ViewComponent framework.\n\n" \ "To fix this issue, choose a different name." ) end raise_if_slot_registered(slot_name) end