Selector (html5rw.Html5rw.Selector)

Supported Selectors

Simple Selectors

Tag: div, p, span
ID: #myid
Class: .myclass
Universal: *

Attribute Selectors

Presence: [attr]
Exact match: [attr="value"]
Contains word: [attr~="value"]
Starts with: [attr^="value"]
Ends with: [attr$="value"]
Contains: [attr*="value"]
Hyphen-separated: [attr|="value"]

Pseudo-classes

:first-child, :last-child
:nth-child(n), :nth-last-child(n)
:only-child
:empty
:not(selector)

Combinators

Descendant: div p (p anywhere inside div)
Child: div > p (p direct child of div)
Adjacent sibling: div + p (p immediately after div)
General sibling: div ~ p (p after div, same parent)

Usage

  let doc = Html5rw.parse reader in

  (* Find all paragraphs *)
  let paragraphs = Html5rw.query doc "p" in

  (* Find links with specific class *)
  let links = Html5rw.query doc "a.external" in

  (* Find table cells in rows *)
  let cells = Html5rw.query doc "tr > td" in

  (* Check if a node matches *)
  let is_active = Html5rw.matches node ".active"

Exceptions

exception Selector_error of string

Raised when a selector string is malformed.

The exception contains an error message describing the parse error.

Sub-modules

module Ast : sig ... end

Abstract syntax tree for parsed selectors.

module Token : sig ... end

Token types for the selector lexer.

Functions

val parse : string -> Ast.selector

Parse a CSS selector string.

raises Selector_error
if the selector is malformed.

val query : Dom.node -> string -> Dom.node list

Query the DOM tree with a CSS selector.

Returns all nodes matching the selector in document order.

raises Selector_error
if the selector is malformed.

  let divs = query root_node "div.content > p"

val matches : Dom.node -> string -> bool

Check if a node matches a CSS selector.

raises Selector_error
if the selector is malformed.

  if matches node ".active" then
    (* node has class "active" *)