Module java.xml
Package org.w3c.dom

# Interface Element

All Superinterfaces:
  `Node`

All Known Subinterfaces:
  `HTMLAnchorElement`, `HTMLAppletElement`, `HTMLAreaElement`, `HTMLBaseElement`, `HTMLBaseFontElement`, `HTMLBodyElement`, `HTMLBRElement`, `HTMLButtonElement`, `HTMLDirectoryElement`, `HTMLDivElement`, `HTMLDListElement`, `HTMLElement`, `HTMLFieldSetElement`, `HTMLFontElement`, `HTMLFormElement`, `HTMLFrameElement`, `HTMLFrameSetElement`, `HTMLHeadElement`, `HTMLHeadingElement`, `HTMLHRElement`, `HTMLHtmlElement`, `HTMLIFrameElement`, `HTMLImageElement`, `HTMLInputElement`, `HTMLIsIndexElement`, `HTMLLabelElement`, `HTMLLegendElement`, `HTMLLIElement`, `HTMLLinkElement`, `HTMLMapElement`, `HTMLMenuElement`, `HTMLMetaElement`, `HTMLModElement`, `HTMLObjectElement`, `HTMLOListElement`, `HTMLOptGroupElement`, `HTMLOptionElement`, `HTMLParagraphElement`, `HTMLParamElement`, `HTMLPreElement`, `HTMLQuoteElement`, `HTMLScriptElement`, `HTMLSelectElement`, `HTMLStyleElement`, `HTMLTableCaptionElement`, `HTMLTableCellElement`, `HTMLTableColElement`, `HTMLTableElement`, `HTMLTableRowElement`, `HTMLTableSectionElement`, `HTMLTextAreaElement`, `HTMLTitleElement`, `HTMLUListElement`

All Known Implementing Classes:
  `IIOMetadataNode`

public interface Element extends Node
The `Element` interface represents an element in an HTML or XML document. Elements may have attributes associated with them; since the `Element` interface inherits from `Node`, the generic `Node` interface attribute `attributes` may be used to retrieve the set of all attributes for an element. There are methods on the `Element` interface to retrieve either an `Attr` object by name or an attribute value by name. In XML, where an attribute value may contain entity references, an `Attr` object should be retrieved to examine the possibly fairly complex sub-tree representing the attribute value. On the other hand, in HTML, where all attributes have simple string values, methods to directly access an attribute value can safely be used as a convenience.

Note: In DOM Level 2, the method `normalize` is inherited from the `Node` interface where it was moved.

See also the Document Object Model (DOM) Level 3 Core Specification.

- ## Field Summary

  ### Fields declared in interface org.w3c.dom.Node

  `ATTRIBUTE_NODE, CDATA_SECTION_NODE, COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, DOCUMENT_NODE, DOCUMENT_POSITION_CONTAINED_BY, DOCUMENT_POSITION_CONTAINS, DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_FOLLOWING, DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, DOCUMENT_POSITION_PRECEDING, DOCUMENT_TYPE_NODE, ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, NOTATION_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `String`
  `getAttribute(String name)`
  Retrieves an attribute value by name.
  `Attr`
  `getAttributeNode(String name)`
  Retrieves an attribute node by name.
  `Attr`
  `getAttributeNodeNS(String namespaceURI, String localName)`
  Retrieves an `Attr` node by local name and namespace URI.
  `String`
  `getAttributeNS(String namespaceURI, String localName)`
  Retrieves an attribute value by local name and namespace URI.
  `NodeList`
  `getElementsByTagName(String name)`
  Returns a `NodeList` of all descendant `Elements` with a given tag name, in document order.
  `NodeList`
  `getElementsByTagNameNS(String namespaceURI, String localName)`
  Returns a `NodeList` of all the descendant `Elements` with a given local name and namespace URI in document order.
  `TypeInfo`
  `getSchemaTypeInfo()`
  The type information associated with this element.
  `String`
  `getTagName()`
  The name of the element.
  `boolean`
  `hasAttribute(String name)`
  Returns `true` when an attribute with a given name is specified on this element or has a default value, `false` otherwise.
  `boolean`
  `hasAttributeNS(String namespaceURI, String localName)`
  Returns `true` when an attribute with a given local name and namespace URI is specified on this element or has a default value, `false` otherwise.
  `void`
  `removeAttribute(String name)`
  Removes an attribute by name.
  `Attr`
  `removeAttributeNode(Attr oldAttr)`
  Removes the specified attribute node.
  `void`
  `removeAttributeNS(String namespaceURI, String localName)`
  Removes an attribute by local name and namespace URI.
  `void`
  `setAttribute(String name, String value)`
  Adds a new attribute.
  `Attr`
  `setAttributeNode(Attr newAttr)`
  Adds a new attribute node.
  `Attr`
  `setAttributeNodeNS(Attr newAttr)`
  Adds a new attribute.
  `void`
  `setAttributeNS(String namespaceURI, String qualifiedName, String value)`
  Adds a new attribute.
  `void`
  `setIdAttribute(String name, boolean isId)`
  If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute .
  `void`
  `setIdAttributeNode(Attr idAttr, boolean isId)`
  If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute .
  `void`
  `setIdAttributeNS(String namespaceURI, String localName, boolean isId)`
  If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute .

  ### Methods declared in interface org.w3c.dom.Node

  `appendChild, cloneNode, compareDocumentPosition, getAttributes, getBaseURI, getChildNodes, getFeature, getFirstChild, getLastChild, getLocalName, getNamespaceURI, getNextSibling, getNodeName, getNodeType, getNodeValue, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, getTextContent, getUserData, hasAttributes, hasChildNodes, insertBefore, isDefaultNamespace, isEqualNode, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, normalize, removeChild, replaceChild, setNodeValue, setPrefix, setTextContent, setUserData`

- ## Method Details

  - ### getTagName

    String getTagName()
    The name of the element. If `Node.localName` is different from `null`, this attribute is a qualified name. For example, in:

         <elementExample id="demo"> ...
         </elementExample> ,

    `tagName` has the value `"elementExample"`. Note that this is case-preserving in XML, as are all of the operations of the DOM. The HTML DOM returns the `tagName` of an HTML element in the canonical uppercase form, regardless of the case in the source HTML document.

  - ### getAttribute

    String getAttribute(String name)
    Retrieves an attribute value by name.
    Parameters:
      `name` - The name of the attribute to retrieve.
    Returns:
      The `Attr` value as a string, or the empty string if that attribute does not have a specified or default value.

  - ### setAttribute

    void setAttribute(String name, String value) throws DOMException
    Adds a new attribute. If an attribute with that name is already present in the element, its value is changed to be that of the value parameter. This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an `Attr` node plus any `Text` and `EntityReference` nodes, build the appropriate subtree, and use `setAttributeNode` to assign it as the value of an attribute.
    To set an attribute with a qualified name and namespace URI, use the `setAttributeNS` method.
    Parameters:
      `name` - The name of the attribute to create or alter.
      `value` - Value to set in string form.
    Throws:
      `DOMException` - INVALID_CHARACTER_ERR: Raised if the specified name is not an XML name according to the XML version in use specified in the `Document.xmlVersion` attribute.
      NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

  - ### removeAttribute

    void removeAttribute(String name) throws DOMException
    Removes an attribute by name. If a default value for the removed attribute is defined in the DTD, a new attribute immediately appears with the default value as well as the corresponding namespace URI, local name, and prefix when applicable. The implementation may handle default values from other schemas similarly but applications should use `Document.normalizeDocument()` to guarantee this information is up-to-date.
    If no attribute with this name is found, this method has no effect.
    To remove an attribute by local name and namespace URI, use the `removeAttributeNS` method.
    Parameters:
      `name` - The name of the attribute to remove.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

  - ### getAttributeNode

    Attr getAttributeNode(String name)
    Retrieves an attribute node by name.
    To retrieve an attribute node by qualified name and namespace URI, use the `getAttributeNodeNS` method.
    Parameters:
      `name` - The name (`nodeName`) of the attribute to retrieve.
    Returns:
      The `Attr` node with the specified name ( `nodeName`) or `null` if there is no such attribute.

  - ### setAttributeNode

    Attr setAttributeNode(Attr newAttr) throws DOMException
    Adds a new attribute node. If an attribute with that name ( `nodeName`) is already present in the element, it is replaced by the new one. Replacing an attribute node by itself has no effect.
    To add a new attribute node with a qualified name and namespace URI, use the `setAttributeNodeNS` method.
    Parameters:
      `newAttr` - The `Attr` node to add to the attribute list.
    Returns:
      If the `newAttr` attribute replaces an existing attribute, the replaced `Attr` node is returned, otherwise `null` is returned.
    Throws:
      `DOMException` - WRONG_DOCUMENT_ERR: Raised if `newAttr` was created from a different document than the one that created the element.
      NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      INUSE_ATTRIBUTE_ERR: Raised if `newAttr` is already an attribute of another `Element` object. The DOM user must explicitly clone `Attr` nodes to re-use them in other elements.

  - ### removeAttributeNode

    Attr removeAttributeNode(Attr oldAttr) throws DOMException
    Removes the specified attribute node. If a default value for the removed `Attr` node is defined in the DTD, a new node immediately appears with the default value as well as the corresponding namespace URI, local name, and prefix when applicable. The implementation may handle default values from other schemas similarly but applications should use `Document.normalizeDocument()` to guarantee this information is up-to-date.
    Parameters:
      `oldAttr` - The `Attr` node to remove from the attribute list.
    Returns:
      The `Attr` node that was removed.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NOT_FOUND_ERR: Raised if `oldAttr` is not an attribute of the element.

  - ### getElementsByTagName

    NodeList getElementsByTagName(String name)
    Returns a `NodeList` of all descendant `Elements` with a given tag name, in document order.
    Parameters:
      `name` - The name of the tag to match on. The special value "*" matches all tags.
    Returns:
      A list of matching `Element` nodes.

  - ### getAttributeNS

    String getAttributeNS(String namespaceURI, String localName) throws DOMException
    Retrieves an attribute value by local name and namespace URI.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute to retrieve.
      `localName` - The local name of the attribute to retrieve.
    Returns:
      The `Attr` value as a string, or the empty string if that attribute does not have a specified or default value.
    Throws:
      `DOMException` - NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### setAttributeNS

    void setAttributeNS(String namespaceURI, String qualifiedName, String value) throws DOMException
    Adds a new attribute. If an attribute with the same local name and namespace URI is already present on the element, its prefix is changed to be the prefix part of the `qualifiedName`, and its value is changed to be the `value` parameter. This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an `Attr` node plus any `Text` and `EntityReference` nodes, build the appropriate subtree, and use `setAttributeNodeNS` or `setAttributeNode` to assign it as the value of an attribute.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute to create or alter.
      `qualifiedName` - The qualified name of the attribute to create or alter.
      `value` - The value to set in string form.
    Throws:
      `DOMException` - INVALID_CHARACTER_ERR: Raised if the specified qualified name is not an XML name according to the XML version in use specified in the `Document.xmlVersion` attribute.
      NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NAMESPACE_ERR: Raised if the `qualifiedName` is malformed per the Namespaces in XML specification, if the `qualifiedName` has a prefix and the `namespaceURI` is `null`, if the `qualifiedName` has a prefix that is "xml" and the `namespaceURI` is different from " http://www.w3.org/XML/1998/namespace", if the `qualifiedName` or its prefix is "xmlns" and the `namespaceURI` is different from "http://www.w3.org/2000/xmlns/", or if the `namespaceURI` is "http://www.w3.org/2000/xmlns/" and neither the `qualifiedName` nor its prefix is "xmlns".
      NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### removeAttributeNS

    void removeAttributeNS(String namespaceURI, String localName) throws DOMException
    Removes an attribute by local name and namespace URI. If a default value for the removed attribute is defined in the DTD, a new attribute immediately appears with the default value as well as the corresponding namespace URI, local name, and prefix when applicable. The implementation may handle default values from other schemas similarly but applications should use `Document.normalizeDocument()` to guarantee this information is up-to-date.
    If no attribute with this local name and namespace URI is found, this method has no effect.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute to remove.
      `localName` - The local name of the attribute to remove.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### getAttributeNodeNS

    Attr getAttributeNodeNS(String namespaceURI, String localName) throws DOMException
    Retrieves an `Attr` node by local name and namespace URI.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute to retrieve.
      `localName` - The local name of the attribute to retrieve.
    Returns:
      The `Attr` node with the specified attribute local name and namespace URI or `null` if there is no such attribute.
    Throws:
      `DOMException` - NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### setAttributeNodeNS

    Attr setAttributeNodeNS(Attr newAttr) throws DOMException
    Adds a new attribute. If an attribute with that local name and that namespace URI is already present in the element, it is replaced by the new one. Replacing an attribute node by itself has no effect.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `newAttr` - The `Attr` node to add to the attribute list.
    Returns:
      If the `newAttr` attribute replaces an existing attribute with the same local name and namespace URI, the replaced `Attr` node is returned, otherwise `null` is returned.
    Throws:
      `DOMException` - WRONG_DOCUMENT_ERR: Raised if `newAttr` was created from a different document than the one that created the element.
      NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      INUSE_ATTRIBUTE_ERR: Raised if `newAttr` is already an attribute of another `Element` object. The DOM user must explicitly clone `Attr` nodes to re-use them in other elements.
      NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### getElementsByTagNameNS

    NodeList getElementsByTagNameNS(String namespaceURI, String localName) throws DOMException
    Returns a `NodeList` of all the descendant `Elements` with a given local name and namespace URI in document order.
    Parameters:
      `namespaceURI` - The namespace URI of the elements to match on. The special value "*" matches all namespaces.
      `localName` - The local name of the elements to match on. The special value "*" matches all local names.
    Returns:
      A new `NodeList` object containing all the matched `Elements`.
    Throws:
      `DOMException` - NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### hasAttribute

    boolean hasAttribute(String name)
    Returns `true` when an attribute with a given name is specified on this element or has a default value, `false` otherwise.
    Parameters:
      `name` - The name of the attribute to look for.
    Returns:
      `true` if an attribute with the given name is specified on this element or has a default value, `false` otherwise.
    Since:
      1.4, DOM Level 2

  - ### hasAttributeNS

    boolean hasAttributeNS(String namespaceURI, String localName) throws DOMException
    Returns `true` when an attribute with a given local name and namespace URI is specified on this element or has a default value, `false` otherwise.
    Per [XML Namespaces] , applications must use the value `null` as the `namespaceURI` parameter for methods if they wish to have no namespace.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute to look for.
      `localName` - The local name of the attribute to look for.
    Returns:
      `true` if an attribute with the given local name and namespace URI is specified or has a default value on this element, `false` otherwise.
    Throws:
      `DOMException` - NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature `"XML"` and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).
    Since:
      1.4, DOM Level 2

  - ### getSchemaTypeInfo

    TypeInfo getSchemaTypeInfo()
    The type information associated with this element.
    Since:
      1.5, DOM Level 3

  - ### setIdAttribute

    void setIdAttribute(String name, boolean isId) throws DOMException
    If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute . This affects the value of `Attr.isId` and the behavior of `Document.getElementById`, but does not change any schema that may be in use, in particular this does not affect the `Attr.schemaTypeInfo` of the specified `Attr` node. Use the value `false` for the parameter `isId` to undeclare an attribute for being a user-determined ID attribute.
    To specify an attribute by local name and namespace URI, use the `setIdAttributeNS` method.
    Parameters:
      `name` - The name of the attribute.
      `isId` - Whether the attribute is a of type ID.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NOT_FOUND_ERR: Raised if the specified node is not an attribute of this element.
    Since:
      1.5, DOM Level 3

  - ### setIdAttributeNS

    void setIdAttributeNS(String namespaceURI, String localName, boolean isId) throws DOMException
    If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute . This affects the value of `Attr.isId` and the behavior of `Document.getElementById`, but does not change any schema that may be in use, in particular this does not affect the `Attr.schemaTypeInfo` of the specified `Attr` node. Use the value `false` for the parameter `isId` to undeclare an attribute for being a user-determined ID attribute.
    Parameters:
      `namespaceURI` - The namespace URI of the attribute.
      `localName` - The local name of the attribute.
      `isId` - Whether the attribute is a of type ID.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NOT_FOUND_ERR: Raised if the specified node is not an attribute of this element.
    Since:
      1.5, DOM Level 3

  - ### setIdAttributeNode

    void setIdAttributeNode(Attr idAttr, boolean isId) throws DOMException
    If the parameter `isId` is `true`, this method declares the specified attribute to be a user-determined ID attribute . This affects the value of `Attr.isId` and the behavior of `Document.getElementById`, but does not change any schema that may be in use, in particular this does not affect the `Attr.schemaTypeInfo` of the specified `Attr` node. Use the value `false` for the parameter `isId` to undeclare an attribute for being a user-determined ID attribute.
    Parameters:
      `idAttr` - The attribute node.
      `isId` - Whether the attribute is a of type ID.
    Throws:
      `DOMException` - NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
      NOT_FOUND_ERR: Raised if the specified node is not an attribute of this element.
    Since:
      1.5, DOM Level 3