Can a custom validation error be added for Custom Component? If yes, can we prevent user from publishing if the field does not have required format?

I have a custom component with a field of type ‘List’.
If user does not add any entry in the list, I want to add a custom error message to user to mention at least one entry is required.

I also want to know if we can prevent the user from publishing the section if the above validation is not met? (in my case the custom component is being used in a section model)

Please let me know how I can achieve this.

Hi @olivela,

Please see this forum post, which demonstrates how to add an OnChange to your custom component’s JSON to run validation.

For example, you might write something like the following, where “MY_LIST” is the name of your list field:

onChange: (options) => {
        if (options.get('MY_LIST').length == 0) {
          alert('MY_LIST must have at least one entry!');

~Logan from

1 Like

Hi Logan,

Thanks for your reply. This helps.
I would also like to know the following:

  1. Instead of adding an alert message, is it possible to add this error message in the custom field section on the front end itself?
  2. Is it possible to prevent the user from publishing the section entry for this case?

Hey @olivela,

Please feel free to add these ideas to a feature request here: Ideas, as they are not currently available.

Thank you!