HTML DOM Nodes
In the HTML DOM (Document Object Model), everything is a node:
- The document itself is a document node
- All HTML elements are element nodes
- All HTML attributes are attribute nodes
- Text inside HTML elements are text nodes
- Comments are comment nodes
The Document Object
When an HTML document is loaded into a web browser, it becomes a document object.
The document object is the root node of the HTML document and the "owner" of all other nodes:
(element nodes, text nodes, attribute nodes, and comment nodes).
The document object provides properties and methods to access all node objects, from within JavaScript.
Tip: The document is a part of the Window object and can be accessed as window.document.
Browser Support
| Object | |||||
|---|---|---|---|---|---|
| Document | Yes | Yes | Yes | Yes | Yes |
The Document Object is supported in all major browsers.
Document Object Properties and Methods
The following properties and methods can be used on HTML documents:
| Property / Method | Description |
|---|---|
| document.activeElement | Returns the currently focused element in the document |
| document.addEventListener() | Attaches an event handler to the document |
| document.adoptNode() | Adopts a node from another document |
| document.anchors | Returns a collection of all <a> elements in the document that have a name attribute |
| document.applets | Returns a collection of all <applet> elements in the document |
| document.baseURI | Returns the absolute base URI of a document |
| document.body | Sets or returns the document's body (the <body> element) |
| document.close() | Closes the output stream previously opened with document.open() |
| document.cookie | Returns all name/value pairs of cookies in the document |
| document.createAttribute() | Creates an attribute node |
| document.createComment() | Creates a Comment node with the specified text |
| document.createDocumentFragment() | Creates an empty DocumentFragment node |
| document.createElement() | Creates an Element node |
| document.createTextNode() | Creates a Text node |
| document.doctype | Returns the Document Type Declaration associated with the document |
| document.documentElement | Returns the Document Element of the document (the <html> element) |
| document.documentMode | Returns the mode used by the browser to render the document |
| document.documentURI | Sets or returns the location of the document |
| document.domain | Returns the domain name of the server that loaded the document |
| document.domConfig | Obsolete. Returns the DOM configuration of the document |
| document.embeds | Returns a collection of all <embed> elements the document |
| document.forms | Returns a collection of all <form> elements in the document |
| document.getElementById() | Returns the element that has the ID attribute with the specified value |
| document.getElementsByClassName() | Returns a NodeList containing all elements with the specified class name |
| document.getElementsByName() | Returns a NodeList containing all elements with a specified name |
| document.getElementsByTagName() | Returns a NodeList containing all elements with the specified tag name |
| document.hasFocus() | Returns a Boolean value indicating whether the document has focus |
| document.head | Returns the <head> element of the document |
| document.images | Returns a collection of all <img> elements in the document |
| document.implementation | Returns the DOMImplementation object that handles this document |
| document.importNode() | Imports a node from another document |
| document.inputEncoding | Returns the encoding, character set, used for the document |
| document.lastModified | Returns the date and time the document was last modified |
| document.links | Returns a collection of all <a> and <area> elements in the document that have a href attribute |
| document.normalize() | Removes empty Text nodes, and joins adjacent nodes |
| document.normalizeDocument() | Removes empty Text nodes, and joins adjacent nodes |
| document.open() | Opens an HTML output stream to collect output from document.write() |
| document.querySelector() | Returns the first element that matches a specified CSS selector(s) in the document |
| document.querySelectorAll() | Returns a static NodeList containing all elements that matches a specified CSS selector(s) in the document |
| document.readyState | Returns the (loading) status of the document |
| document.referrer | Returns the URL of the document that loaded the current document |
| document.removeEventListener() | Removes an event handler from the document (that has been attached with the addEventListener() method) |
| document.renameNode() | Renames the specified node |
| document.scripts | Returns a collection of <script> elements in the document |
| document.strictErrorChecking | Sets or returns whether error-checking is enforced or not |
| document.title | Sets or returns the title of the document |
| document.URL | Returns the full URL of the HTML document |
| document.write() | Writes HTML expressions or JavaScript code to a document |
| document.writeln() | Same as write(), but adds a newline character after each statement |
Warning !!!
In the W3C DOM Core, the Document object inherits all properties and methods from the Node object.
Many of these properties and methods make no sense used on documents.
Avoid using these node object properties and methods on HTML document objects:
| Property / Method | Reason for avoiding |
|---|---|
| document.attributes | Documents don't have attributes |
| document.hasAttributes() | Documents don't have attributes |
| document.nextSibling | Documents don't have siblings |
| document.nodeName | This is always #document |
| document.nodeType | This is always 9 (DOCUMENT_NODE) |
| document.nodeValue | Documents don't have an node value |
| document.ownerDocument | Documents don't have an owner document |
| document.ownerElement | Documents don't have an owner element |
| document.parentNode | Documents don't have a parent node |
| document.previousSibling | Documents don't have siblings |
| document.textContent | Documents don't have a text content |