ShadowRoot

The activeElement read-only property of the Document interface returns the Element within the DOM that is receiving keyboard events such as keydown and keyup. This is usually analogous to the focused element.

The adoptedStyleSheets property of the Document interface is used for setting an array of constructed stylesheets to be used by the document.

The read-only baseURI property of the Node interface returns the absolute base URL of the document containing the node.

The Document.childElementCount read-only property returns the number of child elements of the document.

The read-only childNodes property of the Node interface returns a live NodeList of child nodes of the given element where the first child node is assigned index 0. Child nodes include elements, text and comments.

The read-only children property returns a live HTMLCollection which contains all of the child elements of the document upon which it was called.

The clonable read-only property of the ShadowRoot interface returns true if the shadow root is clonable, and false otherwise.

The customElementRegistry read-only property of the Document interface returns the CustomElementRegistry object associated with this document, or null if one has not been set.

The delegatesFocus read-only property of the ShadowRoot interface returns true if the shadow root delegates focus, and false otherwise.

The read-only firstChild property of the Node interface returns the node's first child in the tree, or null if the node has no children.

The Document.firstElementChild read-only property returns the document's first child Element, or null if there are no child elements.

The Document.fullscreenElement read-only property returns the Element that is currently being presented in fullscreen mode in this document, or null if fullscreen mode is not currently in use.

The host read-only property of the ShadowRoot returns a reference to the DOM element the ShadowRoot is attached to.

The innerHTML property of the ShadowRoot interface gets or sets the HTML markup to the DOM tree inside the ShadowRoot.

The read-only isConnected property of the Node interface returns a boolean indicating whether the node is connected (directly or indirectly) to a Document object.

The read-only lastChild property of the Node interface returns the last child of the node, or null if there are no child nodes.

The Document.lastElementChild read-only property returns the document's last child Element, or null if there are no child elements.

The mode read-only property of the ShadowRoot specifies its mode — either open or closed. This defines whether or not the shadow root's internal features are accessible from JavaScript.

The read-only nextSibling property of the Node interface returns the node immediately following the specified one in their parent's childNodes, or returns null if the specified node is the last child in the parent element.

The read-only nodeName property of Node returns the name of the current node as a string.

The read-only nodeType property of a Node interface is an integer that identifies what the node is. It distinguishes different kinds of nodes from each other, such as elements, text, and comments.

The nodeValue property of the Node interface returns or sets the value of the current node.

The read-only ownerDocument property of the Node interface returns the top-level document object of the node.

The read-only parentElement property of Node interface returns the DOM node's parent Element, or null if the node either has no parent, or its parent isn't a DOM Element. Node.parentNode on the other hand returns any kind of parent, regardless of its type.

The read-only parentNode property of the Node interface returns the parent of the specified node in the DOM tree.

The read-only pictureInPictureElement property of the Document interface returns the Element that is currently being presented in picture-in-picture mode in this document, or null if picture-in-picture mode is not currently in use.

The pointerLockElement read-only property of the Document interface provides the element set as the target for mouse events while the pointer is locked. It is null if lock is pending, pointer is unlocked, or the target is in another document.

The read-only previousSibling property of the Node interface returns the node immediately preceding the specified one in its parent's childNodes list, or null if the specified node is the first in that list.

The serializable read-only property of the ShadowRoot interface returns true if the shadow root is serializable.

The read-only slotAssignment property of the ShadowRoot interface returns the slot assignment mode for the shadow DOM tree. Nodes are either automatically assigned (named) or manually assigned (manual). The value of this property defined using the slotAssignment option when calling Element.attachShadow().

The styleSheets read-only property of the Document interface returns a StyleSheetList of CSSStyleSheet objects, for stylesheets explicitly linked into or embedded in a document.

MDN Reference

The Document.append() method inserts a set of Node objects or strings after the last child of the document. Strings are inserted as equivalent Text nodes.

The appendChild() method of the Node interface adds a node to the end of the list of children of a specified parent node.

The cloneNode() method of the Node interface returns a duplicate of the node on which this method was called. Its parameter controls if the subtree contained in the node is also cloned or not.

The compareDocumentPosition() method of the Node interface reports the position of its argument node relative to the node on which it is called.

The contains() method of the Node interface returns a boolean value indicating whether a node is a descendant of a given node, that is the node itself, one of its direct children (childNodes), one of the children's direct children, and so on.

The elementFromPoint() method, available on the Document object, returns the topmost Element at the specified coordinates (relative to the viewport).

The elementsFromPoint() method of the Document interface returns an array of all elements at the specified coordinates (relative to the viewport). The elements are ordered from the topmost to the bottommost box of the viewport.

The getAnimations() method of the Document interface returns an array of all Animation objects currently in effect whose target elements are descendants of the document. This array includes CSS Animations, CSS Transitions, and Web Animations.

The getElementById() method of the DocumentFragment returns an Element object representing the element whose id property matches the specified string. Since element IDs are required to be unique if specified, they're a useful way to get access to a specific element quickly.

The getHTML() method of the ShadowRoot interface is used to serialize a shadow root's DOM to an HTML string.

The getRootNode() method of the Node interface returns the context object's root, which optionally includes the shadow root if it is available.

The hasChildNodes() method of the Node interface returns a boolean value indicating whether the given Node has child nodes or not.

The insertBefore() method of the Node interface inserts a node before a reference node as a child of a specified parent node.

The isDefaultNamespace() method of the Node interface accepts a namespace URI as an argument. It returns a boolean value that is true if the namespace is the default namespace on the given node and false if not. The default namespace can be retrieved with Node.lookupNamespaceURI() by passing null as the argument.

The isEqualNode() method of the Node interface tests whether two nodes are equal. Two nodes are equal when they have the same type, defining characteristics (for elements, this would be their ID, number of children, and so forth), its attributes match, and so on. The specific set of data points that must match varies depending on the types of the nodes.

The isSameNode() method of the Node interface is a legacy alias the for the === strict equality operator. That is, it tests whether two nodes are the same (in other words, whether they reference the same object).

The lookupNamespaceURI() method of the Node interface takes a prefix as parameter and returns the namespace URI associated with it on the given node if found (and null if not). This method's existence allows Node objects to be passed as a namespace resolver to XPathEvaluator.createExpression() and XPathEvaluator.evaluate().

The lookupPrefix() method of the Node interface returns a string containing the prefix for a given namespace URI, if present, and null if not. When multiple prefixes are possible, the first prefix is returned.

The moveBefore() method of the Document interface moves a given Node inside the Document DOM node as a direct child, before a given reference node.

The normalize() method of the Node interface puts the specified node and all of its sub-tree into a normalized form. In a normalized sub-tree, no text nodes in the sub-tree are empty and there are no adjacent text nodes.

The Document.prepend() method inserts a set of Node objects or strings before the first child of the document. Strings are inserted as equivalent Text nodes.

The Document method querySelector() returns the first Element within the document that matches the specified CSS selector, or group of CSS selectors. If no matches are found, null is returned.

The Document method querySelectorAll() returns a static (not live) NodeList representing a list of the document's elements that match the specified group of selectors.

The removeChild() method of the Node interface removes a child node from the DOM and returns the removed node.

The replaceChild() method of the Node interface replaces a child node within the given (parent) node.

The Document.replaceChildren() method replaces the existing children of a Document with a specified new set of children.

The setHTMLUnsafe() method of the ShadowRoot interface can be used to parse HTML input into a DocumentFragment, optionally filtering out unwanted elements and attributes, and then use it to replace the existing tree in the Shadow DOM.