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Document Object Model

The DOM returned by libxml-parse-html-region (and the other XML parsing functions) is a tree structure where each node has a node name (called a tag), and optional key/value attribute list, and then a list of child nodes. The child nodes are either strings or DOM objects.

(body ((width . "101"))
 (div ((class . "thing"))
  "Foo"
  (div nil
   "Yes")))

Function: dom-node tag &optional attributes &rest children

This function creates a DOM node of type tag. If given, attributes should be a key/value pair list. If given, children should be DOM nodes.

The following functions can be used to work with this structure. Each function takes a DOM node, or a list of nodes. In the latter case, only the first node in the list is used.

Simple accessors:

dom-tag node

Return the tag (also called “node name”) of the node.

dom-attr node attribute

Return the value of attribute in the node. A common usage would be:

(dom-attr img 'href)
=> "https://fsf.org/logo.png"

dom-children node

Return all the children of the node.

dom-non-text-children node

Return all the non-string children of the node.

dom-attributes node

Return the key/value pair list of attributes of the node.

dom-text node

Return all the textual elements of the node as a concatenated string.

dom-texts node

Return all the textual elements of the node, as well as the textual elements of all the children of the node, recursively, as a concatenated string. This function also takes an optional separator to be inserted between the textual elements.

dom-parent dom node

Return the parent of node in dom.

dom-remove dom node

Remove node from dom.

The following are functions for altering the DOM.

dom-set-attribute node attribute value

Set the attribute of the node to value.

dom-append-child node child

Append child as the last child of node.

dom-add-child-before node child before

Add child to node’s child list before the before node. If before is nil, make child the first child.

dom-set-attributes node attributes

Replace all the attributes of the node with a new key/value list.

The following are functions for searching for elements in the DOM. They all return lists of matching nodes.

dom-by-tag dom tag

Return all nodes in dom that are of type tag. A typical use would be:

(dom-by-tag dom 'td)
=> '((td ...) (td ...) (td ...))

dom-by-class dom match

Return all nodes in dom that have class names that match match, which is a regular expression.

dom-by-style dom style

Return all nodes in dom that have styles that match match, which is a regular expression.

dom-by-id dom style

Return all nodes in dom that have IDs that match match, which is a regular expression.

dom-search dom predicate

Return all nodes in dom where predicate returns a non-nil value. predicate is called with the node to be tested as its parameter.

dom-strings dom

Return all strings in dom.

Utility functions:

dom-pp dom &optional remove-empty

Pretty-print dom at point. If remove-empty, don’t print textual nodes that just contain white-space.