Class: ViewComponent::Base
- Inherits:
-
ActionView::Base
- Object
- ActionView::Base
- ViewComponent::Base
- Includes:
- InlineTemplate, Slotable, Translatable, UseHelpers, WithContentHelper
- Defined in:
- lib/view_component/base.rb
Direct Known Subclasses
DocsBuilderComponent, DocsBuilderComponent::ErrorKlassDoc, DocsBuilderComponent::MethodDoc
Constant Summary collapse
- RESERVED_PARAMETER =
:content
Constants included from Translatable
Translatable::HTML_SAFE_TRANSLATION_KEY, Translatable::TRANSLATION_EXTENSIONS
Constants included from Slotable
Class Attribute Summary collapse
Instance Attribute Summary collapse
-
#__vc_original_view_context ⇒ Object
Returns the value of attribute __vc_original_view_context.
Class Method Summary collapse
- .collection_counter_parameter ⇒ Object
- .collection_iteration_parameter ⇒ Object
- .collection_parameter ⇒ Object
-
.compile(raise_errors: false, force: false) ⇒ Object
Compile templates to instance methods, assuming they haven’t been compiled already.
- .compiled? ⇒ Boolean
- .compiler ⇒ Object
-
.config ⇒ ActiveSupport::OrderedOptions
Returns the current config.
- .counter_argument_present? ⇒ Boolean
- .ensure_compiled ⇒ Object
- .format ⇒ Object
- .identifier ⇒ Object
- .inherited(child) ⇒ Object
- .iteration_argument_present? ⇒ Boolean
-
.short_identifier ⇒ Object
Provide identifier for ActionView template annotations.
-
.sidecar_files(extensions) ⇒ Object
Find sidecar files for the given extensions.
-
.strip_trailing_whitespace(value = true) ⇒ Object
Strips trailing whitespace from templates before compiling them.
-
.strip_trailing_whitespace? ⇒ Boolean
Whether trailing whitespace will be stripped before compilation.
-
.type ⇒ Object
we’ll eventually want to update this to support other types.
-
.validate_collection_parameter!(validate_default: false) ⇒ Object
Ensure the component initializer accepts the collection parameter.
-
.validate_initialization_parameters! ⇒ Object
Ensure the component initializer doesn’t define invalid parameters that could override the framework’s methods.
-
.with_collection(collection, **args) ⇒ Object
Render a component for each element in a collection ([documentation](/guide/collections)):.
-
.with_collection_parameter(parameter) ⇒ Object
Set the parameter name used when rendering elements of a collection ([documentation](/guide/collections)):.
Instance Method Summary collapse
-
#before_render ⇒ void
Called before rendering the component.
-
#content ⇒ String
The content passed to the component instance as a block.
-
#content? ⇒ Boolean
Whether ‘content` has been passed to the component.
-
#controller ⇒ ActionController::Base
The current controller.
-
#format ⇒ Object
For caching, such as #cache_if.
-
#helpers ⇒ ActionView::Base
A proxy through which to access helpers.
-
#initialize ⇒ Base
constructor
A new instance of Base.
- #method_missing(method_name, *args) ⇒ Object
-
#output_postamble ⇒ String
Optional content to be returned after the rendered template.
-
#output_preamble ⇒ String
Optional content to be returned before the rendered template.
-
#render(options = {}, args = {}, &block) ⇒ Object
Re-use original view_context if we’re not rendering a component.
-
#render? ⇒ Boolean
Override to determine whether the ViewComponent should render.
-
#render_in(view_context, &block) ⇒ String
Entrypoint for rendering components.
-
#render_parent ⇒ Object
Subclass components that call ‘super` inside their template code will cause a double render if they emit the result.
-
#render_parent_to_string ⇒ Object
Renders the parent component to a string and returns it.
-
#request ⇒ ActionDispatch::Request
The current request.
-
#set_original_view_context(view_context) ⇒ void
Components render in their own view context.
-
#view_cache_dependencies ⇒ Object
For caching, such as #cache_if.
-
#virtual_path ⇒ Object
Exposes .virtual_path as an instance method.
Methods included from WithContentHelper
Methods included from Translatable
Methods included from Slotable
#get_slot, #set_polymorphic_slot, #set_slot
Constructor Details
#initialize ⇒ Base
Returns a new instance of Base.
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# File 'lib/view_component/base.rb', line 192 def initialize(*) end |
Dynamic Method Handling
This class handles dynamic methods through the method_missing method
#method_missing(method_name, *args) ⇒ Object
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# File 'lib/view_component/base.rb', line 240 def method_missing(method_name, *args) # rubocop:disable Style/MissingRespondToMissing super rescue => e # rubocop:disable Style/RescueStandardError e.set_backtrace e.backtrace.tap(&:shift) raise e, <<~MESSAGE.chomp if view_context && e.is_a?(NameError) && helpers.respond_to?(method_name) #{e.} You may be trying to call a method provided as a view helper. Did you mean `helpers.#{method_name}'? MESSAGE raise end |
Class Attribute Details
.source_location ⇒ Object
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# File 'lib/view_component/base.rb', line 446 def source_location @source_location end |
.virtual_path ⇒ Object
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# File 'lib/view_component/base.rb', line 446 def virtual_path @virtual_path end |
Instance Attribute Details
#__vc_original_view_context ⇒ Object
Returns the value of attribute __vc_original_view_context.
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# File 'lib/view_component/base.rb', line 48 def __vc_original_view_context @__vc_original_view_context end |
Class Method Details
.collection_counter_parameter ⇒ Object
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# File 'lib/view_component/base.rb', line 672 def collection_counter_parameter :"#{collection_parameter}_counter" end |
.collection_iteration_parameter ⇒ Object
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# File 'lib/view_component/base.rb', line 682 def collection_iteration_parameter :"#{collection_parameter}_iteration" end |
.collection_parameter ⇒ Object
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# File 'lib/view_component/base.rb', line 667 def collection_parameter provided_collection_parameter || name && name.demodulize.underscore.chomp("_component").to_sym end |
.compile(raise_errors: false, force: false) ⇒ Object
Compile templates to instance methods, assuming they haven’t been compiled already.
Do as much work as possible in this step, as doing so reduces the amount of work done each time a component is rendered.
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# File 'lib/view_component/base.rb', line 577 def compile(raise_errors: false, force: false) compiler.compile(raise_errors: raise_errors, force: force) end |
.compiled? ⇒ Boolean
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# File 'lib/view_component/base.rb', line 563 def compiled? compiler.compiled? end |
.compiler ⇒ Object
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# File 'lib/view_component/base.rb', line 582 def compiler @__vc_compiler ||= Compiler.new(self) end |
.config ⇒ ActiveSupport::OrderedOptions
Returns the current config.
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# File 'lib/view_component/base.rb', line 25 def config ViewComponent::Config.current end |
.counter_argument_present? ⇒ Boolean
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# File 'lib/view_component/base.rb', line 677 def counter_argument_present? initialize_parameter_names.include?(collection_counter_parameter) end |
.ensure_compiled ⇒ Object
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# File 'lib/view_component/base.rb', line 568 def ensure_compiled compile unless compiled? end |
.format ⇒ Object
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# File 'lib/view_component/base.rb', line 593 def format :html end |
.identifier ⇒ Object
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# File 'lib/view_component/base.rb', line 598 def identifier source_location end |
.inherited(child) ⇒ Object
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# File 'lib/view_component/base.rb', line 510 def inherited(child) # Compile so child will inherit compiled `call_*` template methods that # `compile` defines compile # Give the child its own personal #render_template_for to protect against the case when # eager loading is disabled and the parent component is rendered before the child. In # such a scenario, the parent will override ViewComponent::Base#render_template_for, # meaning it will not be called for any children and thus not compile their templates. if !child.instance_methods(false).include?(:render_template_for) && !child.compiled? child.class_eval <<~RUBY, __FILE__, __LINE__ + 1 def render_template_for(variant = nil) # Force compilation here so the compiler always redefines render_template_for. # This is mostly a safeguard to prevent infinite recursion. self.class.compile(raise_errors: true, force: true) # .compile replaces this method; call the new one render_template_for(variant) end RUBY end # If Rails application is loaded, add application url_helpers to the component context # we need to check this to use this gem as a dependency if defined?(Rails) && Rails.application && !(child < Rails.application.routes.url_helpers) child.include Rails.application.routes.url_helpers end # Derive the source location of the component Ruby file from the call stack. # We need to ignore `inherited` frames here as they indicate that `inherited` # has been re-defined by the consuming application, likely in ApplicationComponent. child.source_location = caller_locations(1, 10).reject { |l| l.label == "inherited" }[0].path # If Rails application is loaded, removes the first part of the path and the extension. if defined?(Rails) && Rails.application child.virtual_path = child.source_location.gsub( /(.*#{Regexp.quote(ViewComponent::Base.config.view_component_path)})|(\.rb)/, "" ) end # Set collection parameter to the extended component child.with_collection_parameter provided_collection_parameter if instance_methods(false).include?(:render_template_for) vc_ancestor_calls = defined?(@__vc_ancestor_calls) ? @__vc_ancestor_calls.dup : [] vc_ancestor_calls.unshift(instance_method(:render_template_for)) child.instance_variable_set(:@__vc_ancestor_calls, vc_ancestor_calls) end super end |
.iteration_argument_present? ⇒ Boolean
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# File 'lib/view_component/base.rb', line 687 def iteration_argument_present? initialize_parameter_names.include?(collection_iteration_parameter) end |
.short_identifier ⇒ Object
Provide identifier for ActionView template annotations
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# File 'lib/view_component/base.rb', line 505 def short_identifier @short_identifier ||= defined?(Rails.root) ? source_location.sub("#{Rails.root}/", "") : source_location end |
.sidecar_files(extensions) ⇒ Object
Find sidecar files for the given extensions.
The provided array of extensions is expected to contain strings starting without the dot, example: ‘[“erb”, “haml”]`.
For example, one might collect sidecar CSS files that need to be compiled.
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# File 'lib/view_component/base.rb', line 455 def sidecar_files(extensions) return [] unless source_location extensions = extensions.join(",") # view files in a directory named like the component directory = File.dirname(source_location) filename = File.basename(source_location, ".rb") component_name = name.demodulize.underscore # Add support for nested components defined in the same file. # # for example # # class MyComponent < ViewComponent::Base # class MyOtherComponent < ViewComponent::Base # end # end # # Without this, `MyOtherComponent` will not look for `my_component/my_other_component.html.erb` nested_component_files = if name.include?("::") && component_name != filename Dir["#{directory}/#{filename}/#{component_name}.*{#{extensions}}"] else [] end # view files in the same directory as the component sidecar_files = Dir["#{directory}/#{component_name}.*{#{extensions}}"] sidecar_directory_files = Dir["#{directory}/#{component_name}/#{filename}.*{#{extensions}}"] (sidecar_files - [source_location] + sidecar_directory_files + nested_component_files).uniq end |
.strip_trailing_whitespace(value = true) ⇒ Object
Strips trailing whitespace from templates before compiling them.
“‘ruby class MyComponent < ViewComponent::Base
strip_trailing_whitespace
end “‘
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# File 'lib/view_component/base.rb', line 623 def strip_trailing_whitespace(value = true) self.__vc_strip_trailing_whitespace = value end |
.strip_trailing_whitespace? ⇒ Boolean
Whether trailing whitespace will be stripped before compilation.
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# File 'lib/view_component/base.rb', line 630 def strip_trailing_whitespace? __vc_strip_trailing_whitespace end |
.type ⇒ Object
we’ll eventually want to update this to support other types
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# File 'lib/view_component/base.rb', line 588 def type "text/html" end |
.validate_collection_parameter!(validate_default: false) ⇒ Object
Ensure the component initializer accepts the collection parameter. By default, we don’t validate that the default parameter name is accepted, as support for collection rendering is optional.
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# File 'lib/view_component/base.rb', line 640 def validate_collection_parameter!(validate_default: false) parameter = validate_default ? collection_parameter : provided_collection_parameter return unless parameter return if initialize_parameter_names.include?(parameter) || splatted_keyword_argument_present? # If Ruby can't parse the component class, then the initialize # parameters will be empty and ViewComponent will not be able to render # the component. if initialize_parameters.empty? raise EmptyOrInvalidInitializerError.new(name, parameter) end raise MissingCollectionArgumentError.new(name, parameter) end |
.validate_initialization_parameters! ⇒ Object
Ensure the component initializer doesn’t define invalid parameters that could override the framework’s methods.
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# File 'lib/view_component/base.rb', line 660 def validate_initialization_parameters! return unless initialize_parameter_names.include?(RESERVED_PARAMETER) raise ReservedParameterError.new(name, RESERVED_PARAMETER) end |
.with_collection(collection, **args) ⇒ Object
Render a component for each element in a collection ([documentation](/guide/collections)):
“‘ruby render(ProductsComponent.with_collection(@products, foo: :bar)) “`
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# File 'lib/view_component/base.rb', line 498 def with_collection(collection, **args) Collection.new(self, collection, **args) end |
.with_collection_parameter(parameter) ⇒ Object
Set the parameter name used when rendering elements of a collection ([documentation](/guide/collections)):
“‘ruby with_collection_parameter :item “`
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# File 'lib/view_component/base.rb', line 609 def with_collection_parameter(parameter) @provided_collection_parameter = parameter @initialize_parameters = nil end |
Instance Method Details
#before_render ⇒ void
This method returns an undefined value.
Called before rendering the component. Override to perform operations that depend on having access to the view context, such as helpers.
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# File 'lib/view_component/base.rb', line 180 def before_render # noop end |
#content ⇒ String
The content passed to the component instance as a block.
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# File 'lib/view_component/base.rb', line 285 def content @__vc_content_evaluated = true return @__vc_content if defined?(@__vc_content) @__vc_content = if __vc_render_in_block_provided? view_context.capture(self, &@__vc_render_in_block) elsif __vc_content_set_by_with_content_defined? @__vc_content_set_by_with_content end end |
#content? ⇒ Boolean
Whether ‘content` has been passed to the component.
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# File 'lib/view_component/base.rb', line 300 def content? __vc_render_in_block_provided? || __vc_content_set_by_with_content_defined? end |
#controller ⇒ ActionController::Base
The current controller. Use sparingly as doing so introduces coupling that inhibits encapsulation & reuse, often making testing difficult.
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# File 'lib/view_component/base.rb', line 215 def controller raise ControllerCalledBeforeRenderError if view_context.nil? @__vc_controller ||= view_context.controller end |
#format ⇒ Object
For caching, such as #cache_if
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# File 'lib/view_component/base.rb', line 270 def format @__vc_variant if defined?(@__vc_variant) end |
#helpers ⇒ ActionView::Base
A proxy through which to access helpers. Use sparingly as doing so introduces coupling that inhibits encapsulation & reuse, often making testing difficult.
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# File 'lib/view_component/base.rb', line 225 def helpers raise HelpersCalledBeforeRenderError if view_context.nil? # Attempt to re-use the original view_context passed to the first # component rendered in the rendering pipeline. This prevents the # instantiation of a new view_context via `controller.view_context` which # always returns a new instance of the view context class. # # This allows ivars to remain persisted when using the same helper via # `helpers` across multiple components and partials. @__vc_helpers ||= __vc_original_view_context || controller.view_context end |
#output_postamble ⇒ String
Optional content to be returned after the rendered template.
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# File 'lib/view_component/base.rb', line 172 def output_postamble @@default_output_postamble ||= "".html_safe end |
#output_preamble ⇒ String
Optional content to be returned before the rendered template.
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# File 'lib/view_component/base.rb', line 165 def output_preamble @@default_output_preamble ||= "".html_safe end |
#render(options = {}, args = {}, &block) ⇒ Object
Re-use original view_context if we’re not rendering a component.
This prevents an exception when rendering a partial inside of a component that has also been rendered outside of the component. This is due to the partials compiled template method existing in the parent ‘view_context`,
and not the component's `view_context`.
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# File 'lib/view_component/base.rb', line 202 def render( = {}, args = {}, &block) if .respond_to?(:set_original_view_context) .set_original_view_context(self.__vc_original_view_context) super else __vc_original_view_context.render(, args, &block) end end |
#render? ⇒ Boolean
Override to determine whether the ViewComponent should render.
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# File 'lib/view_component/base.rb', line 187 def render? true end |
#render_in(view_context, &block) ⇒ String
Entrypoint for rendering components.
-
‘view_context`: ActionView context from calling view
-
‘block`: optional block to be captured within the view context
Returns HTML that has been escaped by the respective template handler.
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# File 'lib/view_component/base.rb', line 71 def render_in(view_context, &block) self.class.compile(raise_errors: true) @view_context = view_context self.__vc_original_view_context ||= view_context @output_buffer = ActionView::OutputBuffer.new @lookup_context ||= view_context.lookup_context # required for path helpers in older Rails versions @view_renderer ||= view_context.view_renderer # For content_for @view_flow ||= view_context.view_flow # For i18n @virtual_path ||= virtual_path # For template variants (+phone, +desktop, etc.) @__vc_variant ||= @lookup_context.variants.first # For caching, such as #cache_if @current_template = nil unless defined?(@current_template) old_current_template = @current_template @current_template = self if block && defined?(@__vc_content_set_by_with_content) raise DuplicateContentError.new(self.class.name) end @__vc_content_evaluated = false @__vc_render_in_block = block before_render if render? # Avoid allocating new string when output_preamble and output_postamble are blank rendered_template = safe_render_template_for(@__vc_variant).to_s if output_preamble.blank? && output_postamble.blank? rendered_template else safe_output_preamble + rendered_template + safe_output_postamble end else "" end ensure @current_template = old_current_template end |
#render_parent ⇒ Object
Subclass components that call ‘super` inside their template code will cause a double render if they emit the result.
“‘erb <%= super %> # double-renders <% super %> # doesn’t double-render “‘
‘super` also doesn’t consider the current variant. ‘render_parent` renders the parent template considering the current variant and emits the result without double-rendering.
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# File 'lib/view_component/base.rb', line 134 def render_parent render_parent_to_string nil end |
#render_parent_to_string ⇒ Object
Renders the parent component to a string and returns it. This method is meant to be used inside custom #call methods when a string result is desired, eg.
“‘ruby def call
"<div>#{render_parent_to_string}</div>"
end “‘
When rendering the parent inside an .erb template, use ‘#render_parent` instead.
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# File 'lib/view_component/base.rb', line 149 def render_parent_to_string @__vc_parent_render_level ||= 0 # ensure a good starting value begin target_render = self.class.instance_variable_get(:@__vc_ancestor_calls)[@__vc_parent_render_level] @__vc_parent_render_level += 1 target_render.bind_call(self, @__vc_variant) ensure @__vc_parent_render_level -= 1 end end |
#request ⇒ ActionDispatch::Request
The current request. Use sparingly as doing so introduces coupling that inhibits encapsulation & reuse, often making testing difficult.
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# File 'lib/view_component/base.rb', line 278 def request @request ||= controller.request if controller.respond_to?(:request) end |
#set_original_view_context(view_context) ⇒ void
This method returns an undefined value.
Components render in their own view context. Helpers and other functionality require a reference to the original Rails view context, an instance of ‘ActionView::Base`. Use this method to set a reference to the original view context. Objects that implement this method will render in the component’s view context, while objects that don’t will render in the original view context so helpers, etc work as expected.
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# File 'lib/view_component/base.rb', line 59 def set_original_view_context(view_context) self.__vc_original_view_context = view_context end |
#view_cache_dependencies ⇒ Object
For caching, such as #cache_if
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# File 'lib/view_component/base.rb', line 263 def view_cache_dependencies [] end |
#virtual_path ⇒ Object
Exposes .virtual_path as an instance method
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# File 'lib/view_component/base.rb', line 257 def virtual_path self.class.virtual_path end |