ViewComponent/view_component · error · ViewComponent::MissingCollectionArgumentError

The initializer for COMPONENT doesn't accept the parameter `

Error message

The initializer for COMPONENT doesn't accept the parameter `PARAMETER`, which is required to render it as a collection.

To fix this issue, update the initializer to accept `PARAMETER`.

See [the collections docs](https://viewcomponent.org/guide/collections.html) for more information on rendering collections.

What it means

Error "The initializer for COMPONENT doesn't accept the parameter `PARAMETER`, which is required to render it as a collection. To fix this issue, update the initializer to accept `PARAMETER`. See [the collections docs](https://viewcomponent.org/guide/collections.html) for more information on rendering collections." thrown in ViewComponent/view_component.

Source

Thrown at lib/view_component/base.rb:739

      #
      # @return [Boolean]
      def strip_trailing_whitespace?
        __vc_strip_trailing_whitespace
      end

      # 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.
      # @private
      def __vc_validate_collection_parameter!(validate_default: false)
        parameter = validate_default ? __vc_collection_parameter : __vc_provided_collection_parameter

        return unless parameter
        return if __vc_initialize_parameter_names.include?(parameter) || __vc_splatted_keyword_argument_present?

        raise MissingCollectionArgumentError.new(name, parameter)
      end

      # Ensure the component initializer doesn't define
      # invalid parameters that could override the framework's
      # methods.
      # @private
      def __vc_validate_initialization_parameters!
        return unless __vc_initialize_parameter_names.include?(:content)

        raise ReservedParameterError.new(name, :content)
      end

      # @private
      def __vc_collection_parameter
        @__vc_provided_collection_parameter ||= name && name.demodulize.underscore.chomp("_component").to_sym
      end

      # @private

View on GitHub (pinned to 9f22c36fa7)

Solutions

1. Add the missing parameter to the component's initializer, e.g. def initialize(parameter:) - the parameter name is the singular name derived from the collection variable.
2. If the collection item should use a different name, set `with_collection_parameter :custom_name` in the component and use that name in the initializer.

When it happens

Trigger: Thrown at lib/view_component/base.rb:739 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ViewComponent/view_component@9f22c36fa7 (2026-08-23). Data as JSON: /api/errors/1978421e1b81fa07. Report an issue: GitHub.