Class: Dommy::Attr

Inherits:
Object
  • Object
show all
Includes:
Bridge::Methods, EventTarget, Node
Defined in:
lib/dommy/attr.rb

Overview

Attr — wraps an HTML attribute as a Node-like object. In real DOM each attribute on an element is an Attr; el.getAttributeNode returns the instance, attr.value = "x" mutates the element's attribute, attr.ownerElement points back to the element.

We represent two states:

- "owned" — the Attr is attached to an Element. value reads/writes
go through the element's Makiri attribute slot.
- "detached" — created via `document.createAttribute(name)` but
not yet attached. Value is stored locally; `setAttributeNode`
transfers it to an element.

Constant Summary

Constants included from Node

Node::ATTRIBUTE_NODE, Node::CDATA_SECTION_NODE, Node::COMMENT_NODE, Node::DOCUMENT_FRAGMENT_NODE, Node::DOCUMENT_NODE, Node::DOCUMENT_POSITION_CONTAINED_BY, Node::DOCUMENT_POSITION_CONTAINS, Node::DOCUMENT_POSITION_DISCONNECTED, Node::DOCUMENT_POSITION_FOLLOWING, Node::DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, Node::DOCUMENT_POSITION_PRECEDING, Node::DOCUMENT_TYPE_NODE, Node::ELEMENT_NODE, Node::HTML_NAMESPACE, Node::PROCESSING_INSTRUCTION_NODE, Node::TEXT_NODE, Node::XMLNS_NAMESPACE, Node::XML_NAMESPACE

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Bridge::Methods

included

Methods included from EventTarget

#__dommy_dump_event_failure__, #__internal_deliver_event__, #__internal_process_event_handler_return__, #add_event_listener, capture_flag, #deliver_at, #dispatch_event, #event_name_from_on, #invoke_listener_isolated, js_truthy?, #on_handler, #remove_event_listener, #set_on_handler

Methods included from Node

#compare_document_position, #get_root_node, #is_default_namespace, #is_equal_node, #is_same_node, #lookup_namespace_uri, #lookup_prefix

Constructor Details

#initialize(name, owner: nil, value: "", namespace_uri: nil, prefix: nil, local_name: nil, document: nil) ⇒ Attr

Returns a new instance of Attr.



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# File 'lib/dommy/attr.rb', line 25

def initialize(name, owner: nil, value: "", namespace_uri: nil, prefix: nil, local_name: nil, document: nil)
  qname = name.to_s
  @owner = owner
  # The node document (for baseURI/ownerDocument when detached from an
  # element). Owned attrs derive it from their owner instead.
  @document = document
  @detached_value = value.to_s
  if namespace_uri && !namespace_uri.to_s.empty?
    # Namespaced attributes preserve case and carry prefix / localName.
    @name = qname
    @namespace_uri = namespace_uri.to_s
    @prefix = prefix
    @local_name = (local_name || qname.split(":", 2).last).to_s
  else
    # Null-namespace attribute: use the qualified name verbatim. The casing is
    # already decided by the caller — the backend stores `setAttribute` names
    # lower-cased (HTML) but preserves `setAttributeNS("", "FOO")` as "FOO",
    # and `createAttribute` lower-cases up front — so re-downcasing here would
    # wrongly fold a case-preserved null-namespace attribute.
    @name = qname
    @namespace_uri = nil
    @prefix = nil
    @local_name = local_name ? local_name.to_s : @name
  end
end

Instance Attribute Details

#local_name ⇒ Object (readonly)

Returns the value of attribute local_name.



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# File 'lib/dommy/attr.rb', line 19

def local_name
  @local_name
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/dommy/attr.rb', line 19

def name
  @name
end

#namespace_uri ⇒ Object (readonly)

Returns the value of attribute namespace_uri.



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# File 'lib/dommy/attr.rb', line 19

def namespace_uri
  @namespace_uri
end

#prefix ⇒ Object (readonly)

Returns the value of attribute prefix.



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# File 'lib/dommy/attr.rb', line 19

def prefix
  @prefix
end

Instance Method Details

#__internal_attach__(element) ⇒ Object

Internal: called by Element when the attr is being transferred to (or detached from) an Element.



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# File 'lib/dommy/attr.rb', line 184

def __internal_attach__(element)
  @owner = element
  @detached_value = ""
  nil
end

#__internal_detach__ ⇒ Object 



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# File 'lib/dommy/attr.rb', line 190

def __internal_detach__
  cached = value
  @owner = nil
  @detached_value = cached
  nil
end

#__internal_event_parent__ ⇒ Object 



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# File 'lib/dommy/attr.rb', line 21

def __internal_event_parent__
  nil
end

#__js_call__(method, args) ⇒ Object 



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# File 'lib/dommy/attr.rb', line 147

def __js_call__(method, args)
  case method
  when "lookupNamespaceURI"
    lookup_namespace_uri(args[0])
  when "lookupPrefix"
    lookup_prefix(args[0])
  when "isDefaultNamespace"
    is_default_namespace(args[0])
  when "cloneNode"
    Attr.new(@name, owner: nil, value: value,
                    namespace_uri: @namespace_uri, prefix: @prefix, local_name: @local_name,
                    document: @document || (@owner.respond_to?(:document) ? @owner.document : nil))
  when "isSameNode"
    is_same_node(args[0])
  when "getRootNode"
    get_root_node(args[0])
  when "compareDocumentPosition"
    compare_document_position(args[0])
  when "appendChild", "insertBefore"
    raise DOMException::HierarchyRequestError, "an Attr may not have children"
  when "removeChild", "replaceChild"
    raise DOMException::NotFoundError, "the node to be removed is not a child of this node"
  when "hasChildNodes"
    false
  when "normalize"
    nil
  when "addEventListener"
    add_event_listener(args[0], args[1], args[2])
  when "removeEventListener"
    remove_event_listener(args[0], args[1], args[2])
  when "dispatchEvent"
    dispatch_event(args[0])
  end
end

#__js_get__(key) ⇒ Object 



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# File 'lib/dommy/attr.rb', line 96

def __js_get__(key)
  case key
  when "name"
    @name
  when "value"
    value
  when "nodeName"
    @name
  when "nodeValue"
    value
  when "textContent"
    # Node.textContent for an Attr returns its value (WHATWG DOM).
    value
  when "ownerElement"
    @owner
  when "ownerDocument"
    owner_document
  when "localName"
    @local_name
  when "namespaceURI"
    @namespace_uri
  when "prefix"
    @prefix
  when "nodeType"
    2
  when "baseURI"
    base_uri
  when "specified"
    # Legacy/useless attribute — always true (WHATWG DOM).
    true
  else
    Bridge::ABSENT
  end
end

#__js_set__(key, val) ⇒ Object 



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# File 'lib/dommy/attr.rb', line 131

def __js_set__(key, val)
  case key
  when "value", "nodeValue", "textContent"
    self.value = val
  else
    return Bridge::UNHANDLED
  end

  nil
end

#base_uri ⇒ Object

Node.baseURI — the node document's base URL. Derived from the owner element when attached, else the document the attr was created in.



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# File 'lib/dommy/attr.rb', line 58

def base_uri
  return @owner.base_uri if @owner.respond_to?(:base_uri)

  @document&.base_uri
end

#owner_document ⇒ Object

Node.ownerDocument — the owner element's current document when attached (so it follows the element across adoptNode), else the creation document.



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# File 'lib/dommy/attr.rb', line 66

def owner_document
  return @owner.document if @owner.respond_to?(:document)

  @document
end

#owner_element ⇒ Object

The Element this attr is on, or nil if detached.



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# File 'lib/dommy/attr.rb', line 52

def owner_element
  @owner
end

#value ⇒ Object 



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# File 'lib/dommy/attr.rb', line 72

def value
  if @owner
    if @namespace_uri
      Backend.get_attribute_ns(@owner.__dommy_backend_node__, @namespace_uri, @local_name).to_s
    else
      @owner.__dommy_backend_node__[@name].to_s
    end
  else
    @detached_value
  end
end

#value=(new_value) ⇒ Object 



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# File 'lib/dommy/attr.rb', line 84

def value=(new_value)
  if @owner
    if @namespace_uri
      @owner.set_attribute_ns(@namespace_uri, @name, new_value.to_s)
    else
      @owner.set_attribute(@name, new_value.to_s)
    end
  else
    @detached_value = new_value.to_s
  end
end