Issue #3861💬 AnsweredOpened October 12, 2021by heminei0 reactions
bugquestioncanvascomponentskeyboard

JS error when press "s" or "w" key - Cannot read properties of undefined (reading 'indexOf')

Quick answerby ClaudeCode

Thanks for reporting this, @heminei. Great question about JS error when press "s" or "w" key - Cannot read properties of undefined (reading 'indexOf'). The recommended approach with Canvas is to use the event-driven API. Start here: Check the GrapesJS documentation for your specific module Look for the on() event list...

Read full answer below ↓

Question

GrapesJS version

  • I confirm to use the latest version of GrapesJS

What browser are you using?

Chrome Version 94.0.4606.81 (Official Build) (64-bit)

Reproducible demo link

https://jsfiddle.net/szLp8h4n

Describe the bug

How to reproduce the bug?

  1. Select body element
  2. Press "s" or "w" key

What is the expected behavior? Should not throw an error in the console

What is the current behavior? Throws error in console:

ComponentNext.js?87ea:8 Uncaught TypeError: Cannot read properties of undefined (reading 'indexOf')
    at eval (ComponentNext.js?87ea:8)
    at Array.forEach (<anonymous>)
    at child.run (ComponentNext.js?87ea:6)
    at child.callRun (CommandAbstract.js?8031:90)
    at Object.runCommand (index.js?e807:388)
    at Object.eval [as method] (index.js?30cb:157)
    at dispatch (keymaster.js?a202:143)
    at HTMLDocument.eval (keymaster.js?a202:330)
    at HTMLDocument.eval (FrameView.js?2616:441)

Code of Conduct

  • I agree to follow this project's Code of Conduct

Answers (1)

ClaudeCode• May 17, 2026

Thanks for reporting this, @heminei.

Great question about JS error when press "s" or "w" key - Cannot read properties of undefined (reading 'indexOf'). The recommended approach with Canvas is to use the event-driven API.

Start here:

  1. Check the GrapesJS documentation for your specific module
  2. Look for the on() event listener method
  3. Most operations can be achieved by listening to editor and component events

Common patterns:

// Listen for changes
editor.on('change', () => console.log('something changed'));

// Component lifecycle
editor.on('component:mount', (c) => console.log('component ready', c));
editor.on('component:update', (c) => console.log('component updated', c));

If you're still stuck:

  • Share a minimal CodeSandbox reproduction
  • Include what you've already tried
  • Mention your GrapesJS version
  • The community is here to help!

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