Md.Listener behaviour (md v0.15.1)

The listener behaviour to attach to the parser to receive callbacks when the elements are encountered and processed.

Summary

Types

attributes()

branch()

callback()

context()

element()

leaf()

parse_mode()

state()

trace()

Callbacks

element(context, state)

Called for every parsing event.

Functions

__using__(opts \\ [])

Generates a listener with no-op handlers for every event.

Types

attributes()

@type attributes() :: XmlBuilder.Element.attrs()

branch()

@type branch() :: XmlBuilder.Element.content()

callback()

@type callback() :: (state() -> state())

context()

@type context() ::
  :start
  | :break
  | :linefeed
  | :whitespace
  | :custom
  | {:substitute, {binary(), binary()}}
  | {:esc, binary()}
  | {:char, binary()}
  | {:tag, {binary(), element()}, atom()}
  | :finalize
  | :end

element()

@type element() :: XmlBuilder.Element.name()

leaf()

@type leaf() :: XmlBuilder.Element.content()

parse_mode()

@type parse_mode() ::
  :idle
  | :finished
  | :raw
  | :skip
  | :comment
  | {:comment, binary()}
  | :magnet
  | :md
  | {:outer, :md}
  | {:linefeed, non_neg_integer()}
  | {:nested, element(), non_neg_integer()}
  | {:inner, :raw}
  | {:inner, element(), non_neg_integer()}

state()

@type state() :: %Md.Parser.State{
  path: [trace()],
  mode: [parse_mode()],
  type: module(),
  ast: [branch()],
  listener: nil | module(),
  payload: any(),
  bag: %{
    indent: [non_neg_integer() | atom()],
    stock: [branch()],
    deferred: [{binary(), binary()}]
  }
}

trace()

@type trace() :: branch()

Callbacks

element(context, state)

@callback element(context(), state()) :: :ok | {:update, state()}

Called for every parsing event.

Return :ok to leave the parser state untouched, or {:update, state} to replace it -- which is how a listener rewrites the AST as it is built.

Functions

using(opts \\ [])

(macro)

Generates a listener with no-op handlers for every event.

Options

:emoji -- the marker used by the default debug logging. Default: "📑".
:debug -- when true, the generated handle_start/1, handle_end/1 and handle_tag/2 log at :debug level. Default: false.

A listener should be silent unless it is explicitly asked to be: a library that logs on every parsed element is unusable in production.