Angular-form-error is a helper directive to add CSS classes to your markup depending on the validation state of the form and form fields.

    <div form-error="'email'" class="form-group">
        <label>Email address</label>
        <input name="email" ng-model="data.email" type="email" required class="form-control">
    </div>

The directive needs the input name (name=...) and will set the CSS class form-error when the field is invalid AND the field is dirty OR the form is submitted.

You can change the default behaviour by using the form-error-logic attribute.

<div form-error="'name'" form-error-logic="alternativeLogic" class="form-group">

Define the CSS class(es) and logic in your controller:

$scope.alternativeLogic = {
    'has-error': function(field, form) {
        return field.invalid && form.submitted
    }
};