You can try the following:
dynamicForm.setFieldErrors(fieldName, errorText, true);
Here is the link for documentation.
Or the following is also similar:
dynamicForm.setErrors(map, true);
Here is the link for documentation.
Question
I am trying to get customized messages from SmartGWT (e.g. change "Must be a date" for another custom message). How can I get that String before it is shown to the user so I can edit it?
The question is for FormItem
subclasses.