Behaviour for SAX event handlers.

Drop-in replacement for Saxy.Handler. Implement handle_event/3 to process XML parsing events.

Event Types

• :start_document — emitted once at the beginning. Data is a keyword list with optional :version, :encoding, and :standalone keys.
• :start_element — emitted for each opening tag. Data is {name, attributes} where attributes is a list of {name, value} string tuples.
• :characters — emitted for text content. Data is a binary string.
• :cdata — emitted for CDATA sections. Data is a binary string.
• :end_element — emitted for each closing tag. Data is the element name (binary).
• :end_document — emitted once at the end. Data is {}.

Return Values

• {:ok, new_state} — continue parsing with updated state
• {:stop, value} — stop parsing early, return {:ok, value}
• {:halt, value} — halt parsing, return {:halt, value, rest}

Example

defmodule CountingHandler do
  @behaviour RustyXML.Handler

  @impl true
  def handle_event(:start_element, _data, count), do: {:ok, count + 1}
  def handle_event(_event, _data, count), do: {:ok, count}
end

RustyXML.parse_string("<root><a/><b/></root>", CountingHandler, 0)
#=> {:ok, 3}