from django.core.validators import ValidationError, CriticalValidationError
from django.newforms import ValidationError as newformsValidationError

def run_oldforms_validator(field_name, form, validator):
    """
    Run an oldforms validator against a newforms form.  This function is nearly
    identical to oldforms.FormField.run_validator.
    """
    # Use form.data here instead of form.clean_data because the oldforms
    # validators worked with the raw POST data.
    if form.fields[field_name].required or \
            form.data.get(field_name, None) or \
            hasattr(validator, 'always_test'):
        validator(form.data.get(field_name, ''), form.data)

def run_oldforms_validators(field_name, form, validator_list):
    """
    Run a list of oldforms validators against a newforms form.  This function
    is nearly identical to oldforms.FormField.run_validators.
    """
    errors = {}
    try:
        for validator in validator_list:
            try:
                run_oldforms_validator(field_name, form, validator)
            except ValidationError, e:
                errors.setdefault(field_name, []).extend(e.messages)
    # If a CriticalValidationError is raised, ignore any other ValidationErrors
    # for this particular field
    except CriticalValidationError, e:
        errors.setdefault(field_name, []).extend(e.messages)
    if errors:
        raise newformsValidationError(errors[field_name])