Class: CustomElementsManifestParser::Nodes::MixinDeclaration

Inherits:
BaseStruct
  • Object
show all
Includes:
Mixins::HasParentModule
Defined in:
lib/custom_elements_manifest_parser/nodes/mixin_declaration.rb

Overview

A description of a class mixin.

Mixins are functions which generate a new subclass of a given superclass. This interfaces describes the class and custom element features that are added by the mixin. As such, it extends the CustomElement interface and ClassLike interface.

Since mixins are functions, it also extends the FunctionLike interface. This means a mixin is callable, and has parameters and a return type.

The return type is often hard or impossible to accurately describe in type systems like TypeScript. It requires generics and an extends operator that TypeScript lacks. Therefore it's recommended that the return type is left empty. The most common form of a mixin function takes a single argument, so consumers of this interface should assume that the return type is the single argument subclassed by this declaration.

A mixin should not have a superclass. If a mixins composes other mixins, they should be listed in the mixins field.

See https://justinfagnani.com/2015/12/21/real-mixins-with-javascript-classes/ for more information on the classmixin pattern in JavaScript.

This JavaScript mixin declaration:

const MyMixin = (base) => class extends base {
  foo() { ... }
}

Is described by this JSON:

{
  "kind": "mixin",
  "name": "MyMixin",
  "parameters": [
    {
      "name": "base",
    }
  ],
  "members": [
    {
      "kind": "method",
      "name": "foo",
    }
  ]
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Mixins::HasParentModule

#parent_module

Instance Attribute Details

#kind ⇒ "mixin"

Returns:

  • ("mixin") 


78
 
# File 'lib/custom_elements_manifest_parser/nodes/mixin_declaration.rb', line 78

attribute :kind, Types.Value("mixin")

Class Method Details

.kind ⇒ "mixin"

Returns:

  • ("mixin") 


81
 
# File 'lib/custom_elements_manifest_parser/nodes/mixin_declaration.rb', line 81

def self.kind; 'mixin'; end

Instance Method Details

#visit(parser:) ⇒ Object 



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# File 'lib/custom_elements_manifest_parser/nodes/mixin_declaration.rb', line 83

def visit(parser:)
  hash = {}

  hash = hash.merge(
    # Structs::FunctionLikeStruct.build_hash(parser: parser, struct: self),
    Structs::CustomElementLikeStruct.build_hash(parser: parser, struct: self),
    Structs::DeclarableNodeStruct.build_hash(parser: parser, struct: self),
  )

  new(hash)
end