required

Checks that the value is present: not missing, not null and not an empty string. Note that 0 and false are valid values.

Error code: REQUIRED

Live example · edit rules or inputOpen in playground

rules

{
    first_name: 'required',
    last_name: 'required'
}

{ first_name: 'required', last_name: 'required' }

input

{
    first_name: 'Viktor',
    last_name: ''
}

{ first_name: 'Viktor', last_name: '' }

Invaliderrors

{
  "last_name": "REQUIRED"
}

All other rules except not_empty and not_empty_list skip empty values, so combine them with required for mandatory fields:

{ first_name: ['required', { min_length: 2 }] }