Class: ViewComponent::Base

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

Class Attribute Summary collapse

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 84

def initialize(*); end

Class Attribute Details

.source_location ⇒ Object

Returns the value of attribute source_location.



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# File 'lib/view_component/base.rb', line 144

def source_location
  @source_location
end

Class Method Details

.call_method_name(variant) ⇒ Object 



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# File 'lib/view_component/base.rb', line 159

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

.collection_parameter_name ⇒ Object 



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# File 'lib/view_component/base.rb', line 240

def collection_parameter_name
  (@with_collection_parameter || name.demodulize.underscore.chomp("_component")).to_sym
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 178

def compile(raise_template_errors: false)
  return if compiled?

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

  define_singleton_method(:variants) do
    templates.map { |template| template[:variant] } + variants_from_inline_calls(inline_calls)
  end

  # If template name annotations are turned on, a line is dynamically
  # added with a comment. In this case, we want to return a different
  # starting line number so errors that are raised will point to the
  # correct line in the component template.
  line_number =
    if ActionView::Base.respond_to?(:annotate_template_file_names) &&
      ActionView::Base.annotate_template_file_names
      -2
    else
      -1
    end

  templates.each do |template|
    class_eval <<-RUBY, template[:path], line_number
      def #{call_method_name(template[:variant])}
        @output_buffer = ActionView::OutputBuffer.new
        #{compiled_template(template[:path])}
      end
    RUBY
  end

  @compiled = true
end

.compile! ⇒ Object 



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# File 'lib/view_component/base.rb', line 171

def compile!
  compile(raise_template_errors: true)
end

.compiled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/view_component/base.rb', line 167

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

.format ⇒ Object 



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# File 'lib/view_component/base.rb', line 219

def format
  :html
end

.identifier ⇒ Object 



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# File 'lib/view_component/base.rb', line 223

def identifier
  source_location
end

.inherited(child) ⇒ Object 



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# File 'lib/view_component/base.rb', line 146

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

  super
end

.short_identifier ⇒ Object 



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# File 'lib/view_component/base.rb', line 80

def self.short_identifier
  @short_identifier ||= defined?(Rails.root) ? source_location.sub("#{Rails.root}/", "") : source_location
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 215

def type
  "text/html"
end

.with_collection(*args) ⇒ Object

Render a component collection.



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# File 'lib/view_component/base.rb', line 19

def self.with_collection(*args)
  Collection.new(self, *args)
end

.with_collection_parameter(param) ⇒ Object

Support overriding this component’s collection parameter name



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# File 'lib/view_component/base.rb', line 236

def with_collection_parameter(param)
  @with_collection_parameter = param
end

.with_content_areas(*areas) ⇒ Object 



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# File 'lib/view_component/base.rb', line 227

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 72

def before_render_check
  # noop
end

#controller ⇒ Object 



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

def controller
  @controller ||= view_context.controller
end

#format ⇒ Object

:nodoc:



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# File 'lib/view_component/base.rb', line 112

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 99

def helpers
  @helpers ||= view_context
end

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



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# File 'lib/view_component/base.rb', line 86

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 76

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 47

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 108

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 104

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 116

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