formatMarkdownSymbol function

Future<bool> formatMarkdownSymbol(EditorState editorState, bool shouldFormat(Node node), bool predicate(Node node, String text, Selection selection), List<Node> nodesBuilder(String text, Node node, Delta delta),)

Formats the current node to specified markdown style.

For example, bulleted list: '- ' numbered list: '1. ' quote: '" ' ...

The nodeBuilder can return a list of nodes, which will be inserted into the document. For example, when converting a bulleted list to a heading and the heading is not allowed to contain children, then the nodeBuilder should return a list of nodes, which contains the heading node and the children nodes.

Implementation

Future<bool> formatMarkdownSymbol(
  EditorState editorState,
  bool Function(Node node) shouldFormat,
  bool Function(
    Node node,
    String text,
    Selection selection,
  ) predicate,
  List<Node> Function(
    String text,
    Node node,
    Delta delta,
  ) nodesBuilder,
) async {
  final selection = editorState.selection;
  if (selection == null || !selection.isCollapsed) {
    return false;
  }

  final position = selection.end;
  final node = editorState.getNodeAtPath(position.path);

  if (node == null || !shouldFormat(node)) {
    return false;
  }

  // Get the text from the start of the document until the selection.
  final delta = node.delta;
  if (delta == null) {
    return false;
  }
  final text = delta.toPlainText().substring(0, selection.end.offset);

  // If the text doesn't match the predicate, then we don't want to
  // format it.
  if (!predicate(node, text, selection)) {
    return false;
  }

  final afterSelection = Selection.collapsed(
    Position(
      path: node.path,
      offset: 0,
    ),
  );

  final formattedNodes = nodesBuilder(text, node, delta);

  // Create a transaction that replaces the current node with the
  // formatted node.
  final transaction = editorState.transaction
    ..insertNodes(
      node.path,
      formattedNodes,
    )
    ..deleteNode(node)
    ..afterSelection = afterSelection;

  await editorState.apply(transaction);
  return true;
}