CodeMirror Indentation Markers

A CodeMirror extension that renders indentation markers using a heuristic similar to what other popular editors, like Ace and Monaco, use.

Example

Usage

import { basicSetup } from 'codemirror';
import { EditorState } from '@codemirror/state';
import { EditorView } from '@codemirror/view';
import { indentationMarkers } from '@replit/codemirror-indentation-markers';

const doc = `
def max(a, b):
  if a > b:
    return a
  else:
    return b
`

new EditorView({
  state: EditorState.create({
    doc,
    extensions: [basicSetup, indentationMarkers()],
  }),
  parent: document.querySelector('#editor'),
});

Options

You can provide an options object to indentationMarkers() with the following optional properties:

highlightActiveBlock

Boolean that determines whether the active block marker is styled differently. Setting this to false provides a significant performance enhancement because it means that markers do not need to be regenerated when the selection changes. Defaults to true.
- hideFirstIndent
  
  Boolean that determines whether markers in the first column are omitted. Defaults to false.

Example

new EditorView({
  state: EditorState.create({
    doc,
    extensions: [
      basicSetup,
      indentationMarkers({
        highlightActiveBlock: false,
        hideFirstIndent: true,
      })
    ],
  }),
  parent: document.querySelector('#editor'),
});