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Manipulation

Accessing Element Properties

  • tag(elem) — get the tag of an element as a symbol
  • attrs(elem) — return the attributes dict
  • getattr(elem, name[, default]) — get attribute value or nothing/default
  • setattr!(elem, name, value) — set attribute (validated)
  • hasattr(elem, name) — check whether an attribute exists

Children and Text

  • children(elem) — return the children array
  • text(elem) — recursively extract all text content

Finding Elements

  • findfirst(f, elem) / findfirst(f, doc) — find the first element (pre-order DFS) matching predicate f
  • getbyid(elem, id) / getbyid(doc, id) — find element by id attribute
  • applyif!(condition, f!, elem) — apply a mutating function to all matching elements

Examples

# Find the first <a> tag
findfirst(x -> tag(x) == :a, doc.root)

# Find element by id
getbyid(doc, "main-content")

# Apply a function to all matching elements
applyif!(x -> tag(x) == :div, x -> setattr!(x, "class", "wide"), doc)

CSS Class Helpers

  • hasclass(elem, cls) — check if element has a CSS class
  • addclass!(elem, cls) — add a CSS class (no-op if already present)
  • removeclass!(elem, cls) — remove a CSS class
  • replaceclass!(elem, old, new) — replace one class with another; pass nothing to remove

Examples

el = HTMLElement(:div)
addclass!(el, "active")
addclass!(el, "highlight")
hasclass(el, "active")       # true
replaceclass!(el, "active", "inactive")
removeclass!(el, "highlight")

Validation

Attribute names and CSS class values are validated automatically when using setattr!, addclass!, replaceclass!, and bracket assignment.

Invalid attribute names raise InvalidAttributeException. Invalid class values raise ArgumentError or InvalidAttributeException.

Use the @validate macro directly:

@validate :attr "data-value"          # validate attribute name
@validate :class "my-class"           # validate class name
@validate :attr ["id", "data-value"]  # validate multiple names
@validate :class ["cls1", "cls2"]     # validate multiple classes

Pretty Printing

prettyprint(elem) / prettyprint(io, elem) — output nicely indented HTML:

prettyprint(doc)              # print document to stdout
prettyprint(io, doc)          # print to IO stream
prettyprint(elem)             # print element