Editor hooks

[mixonic]

Per the 0.4.0 epic, create public hooks for the lifecycle of abstract changes and rendering.

editor.didUpdatePost((postEditor) => {
  postEditor.doSomething(editor.builder.createMarker());
  postEditor.forEachNode((node) => {
    if (node.type === SECTION) {
      if (node.markers.length === 1 && node.value === '*') {
        let list = editor.builder.createListSection('li');
        postEditor.replaceSection(node.section, list);
      }
    }
  });
});

editor.willRender(() => {
  if (!editor.post.isEmpty) {
    $('.placeholder').remove();
  }
});

editor.didRender(() => {
  if (editor.post.isEmpty) {
    $('.placeholder').append(document.body);
    $('.placeholder').positionAt(editor.element.firstChild);
    $('.placeholder').click(() => {
      editor.cursor.moveToSection(editor.post.sections.head);
    });
  }
});

[mixonic]

@rlivsey FYI this is what we are thinking hook-wise.

[mixonic]

Closing in favor of #95