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Tree Traversal

HTMLForge re-exports convenience aliases for common tree traversal strategies from AbstractTrees.jl.

  • preorder(node) — pre-order depth-first traversal
  • postorder(node) — post-order depth-first traversal
  • breadthfirst(node) — breadth-first (level-order) traversal

Example

using HTMLForge

doc = parsehtml("""
    <html>
      <body>
        <div>
          <p></p> <a></a> <p></p>
        </div>
        <div>
          <span></span>
        </div>
      </body>
    </html>
""")

for elem in preorder(doc.root)
    println(tag(elem))
end
# HTML, head, body, div, p, a, p, div, span

for elem in postorder(doc.root)
    println(tag(elem))
end
# head, p, a, p, div, span, div, body, HTML

for elem in breadthfirst(doc.root)
    println(tag(elem))
end
# HTML, head, body, div, div, p, a, p, span

You can also use the iterators from AbstractTrees.jl directly (PreOrderDFS, PostOrderDFS, StatelessBFS).

Comparison and Equality

HTMLDocument, HTMLElement, and HTMLText all support ==, isequal, and hash. Two elements are considered equal if they have the same tag, attributes, and children (parents are ignored):

HTMLElement(:div) == HTMLElement(:div)  # true