Class: ViewComponent::Base

Inherits:
ActionView::Base
  • Object
show all
Includes:
ActiveSupport::Configurable, Previewable
Defined in:
lib/view_component/base.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Base

Returns a new instance of Base.



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# File 'lib/view_component/base.rb', line 74

def initialize(*); end

Class Method Details

.call_method_name(variant) ⇒ Object 



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# File 'lib/view_component/base.rb', line 142

def call_method_name(variant)
  if variant.present? && variants.include?(variant)
    "call_#{variant}"
  else
    "call"
  end
end

.compile(raise_template_errors: false) ⇒ Object

Compile templates to instance methods, assuming they haven’t been compiled already. We could in theory do this on app boot, at least in production environments. Right now this just compiles the first time the component is rendered.



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# File 'lib/view_component/base.rb', line 175

def compile(raise_template_errors: false)
  return if compiled? || inlined?

  if template_errors.present?
    raise ViewComponent::TemplateError.new(template_errors) if raise_template_errors
    return false
  end

  templates.each do |template|
    class_eval "      def \#{call_method_name(template[:variant])}\n        @output_buffer = ActionView::OutputBuffer.new\n        \#{compiled_template(template[:path])}\n      end\n    RUBY\n  end\n\n  @compiled = true\nend\n", template[:path], -1

.compile! ⇒ Object 



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# File 'lib/view_component/base.rb', line 168

def compile!
  compile(raise_template_errors: true)
end

.compiled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/view_component/base.rb', line 160

def compiled?
  @compiled && ActionView::Base.cache_template_loading
end

.identifier ⇒ Object 



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# File 'lib/view_component/base.rb', line 204

def identifier
  source_location
end

.inherited(child) ⇒ Object 



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# File 'lib/view_component/base.rb', line 134

def inherited(child)
  if defined?(Rails)
    child.include Rails.application.routes.url_helpers unless child < Rails.application.routes.url_helpers
  end

  super
end

.inlined? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/view_component/base.rb', line 164

def inlined?
  instance_methods(false).grep(/^call/).present? && templates.empty?
end

.source_location ⇒ Object 



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# File 'lib/view_component/base.rb', line 150

def source_location
  @source_location ||=
    begin
      # Require `#initialize` to be defined so that we can use `method#source_location`
      # to look up the filename of the component.
      initialize_method = instance_method(:initialize)
      initialize_method.source_location[0] if initialize_method.owner == self
    end
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 200

def type
  "text/html"
end

.variants ⇒ Object 



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# File 'lib/view_component/base.rb', line 195

def variants
  templates.map { |template| template[:variant] }
end

.with_content_areas(*areas) ⇒ Object 



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# File 'lib/view_component/base.rb', line 208

def with_content_areas(*areas)
  if areas.include?(:content)
    raise ArgumentError.new ":content is a reserved content area name. Please use another name, such as ':body'"
  end
  attr_reader *areas
  self.content_areas = areas
end

Instance Method Details

#before_render_check ⇒ Object 



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# File 'lib/view_component/base.rb', line 66

def before_render_check
  # noop
end

#controller ⇒ Object 



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# File 'lib/view_component/base.rb', line 84

def controller
  @controller ||= view_context.controller
end

#format ⇒ Object

:nodoc:



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# File 'lib/view_component/base.rb', line 102

def format # :nodoc:
  @variant
end

#helpers ⇒ Object

Provides a proxy to access helper methods through



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# File 'lib/view_component/base.rb', line 89

def helpers
  @helpers ||= view_context
end

#render(options = {}, args = {}, &block) ⇒ Object 



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# File 'lib/view_component/base.rb', line 76

def render(options = {}, args = {}, &block)
  if options.is_a?(String) || (options.is_a?(Hash) && options.has_key?(:partial))
    view_context.render(options, args, &block)
  else
    super
  end
end

#render? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/view_component/base.rb', line 70

def render?
  true
end

#render_in(view_context, &block) ⇒ Object

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

Example subclass:

app/components/my_component.rb: class MyComponent < ViewComponent::Base

def initialize(title:)
  @title = title
end

end

app/components/my_component.html.erb <span title=“<%= @title %>”>Hello, <%= content %>!</span>

In use: <%= render MyComponent.new(title: “greeting”) do %>world<% end %> returns: <span title=“greeting”>Hello, world!</span>



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# File 'lib/view_component/base.rb', line 41

def render_in(view_context, &block)
  self.class.compile!
  @view_context = view_context
  @view_renderer ||= view_context.view_renderer
  @lookup_context ||= view_context.lookup_context
  @view_flow ||= view_context.view_flow
  @virtual_path ||= virtual_path
  @variant = @lookup_context.variants.first

  old_current_template = @current_template
  @current_template = self

  @content = view_context.capture(self, &block) if block_given?

  before_render_check

  if render?
    send(self.class.call_method_name(@variant))
  else
    ""
  end
ensure
  @current_template = old_current_template
end

#view_cache_dependencies ⇒ Object 



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# File 'lib/view_component/base.rb', line 98

def view_cache_dependencies
  []
end

#virtual_path ⇒ Object

Removes the first part of the path and the extension.



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# File 'lib/view_component/base.rb', line 94

def virtual_path
  self.class.source_location.gsub(%r{(.*app/components)|(\.rb)}, "")
end

#with(area, content = nil, &block) ⇒ Object 



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# File 'lib/view_component/base.rb', line 106

def with(area, content = nil, &block)
  unless content_areas.include?(area)
    raise ArgumentError.new "Unknown content_area '#{area}' - expected one of '#{content_areas}'"
  end

  if block_given?
    content = view_context.capture(&block)
  end

  instance_variable_set("@#{area}".to_sym, content)
  nil
end