When you save a record, set an error on the field if a file attached to an attachment field has an extension other than the ones specified.
This plugin does not support smartphones. Use it on a computer.
Choose the attachment fields and the allowed extensions. For example, to accept only images, specify the image extensions you allow.
Depending on the settings, this customization runs at the following times. Any configured conditions are also evaluated.
Enter or select a value for each setting unless it is marked optional.
Choose the attachment fields whose file extensions will be checked. You can select more than one field.
The following field types can be selected.
Fields inside tables cannot be selected.
Enter allowed extensions without a leading period. Separate multiple extensions with line breaks or commas.
Enter the message to show when the input fails the check. Explain how the user can correct it.
Initial value: This type of file cannot be attached.
The following actions and conditions are useful when building similar behavior in customization mode.