Server-side Validation

As the client can not be trusted to validate all the data correctly, there will be server-side checks for the validity of the received value(s).

If such a validation fails, the form is sent back to the client with additional validation error information.

Structure

Each element that can hold a validator property can also have a validation_error property. Additionally the choice element can have a validation_error in the allow_selected property.

The validation_error property is an object holding the rule name as a key (e.g. min_length). The value corresponding to the key is a boolean which indicates whether or not the validation rule has been broken. Most of the time unbroken validation rules will not be present in the validation_error object.

{
    "type": ?Boolean,
    "min_length": ?Boolean,
    "max_length": ?Boolean,
    "required": ?Boolean,
    "min_value": ?Boolean,
    "max_value": ?Boolean,
    "numeric_only": ?Boolean,
    "numeric": ?Boolean, /* deprecated */
    "letters_uppercase": ?Boolean, /* deprecated */
    "letters_lowercase": ?Boolean, /* deprecated */
    "symbols": ?Boolean, /* deprecated */
    "char_blacklist": ?Boolean,
    "pattern": ?Boolean,
    "allow_selected_min": ?Boolean,
    "allow_selected_max": ?Boolean,
    "option_disabled": ?Boolean,
    "valid_options": ?Boolean
}

Handling Validation Errors

It is recommended to show a suitable error message if a validation rule has been broken.

Notable Cases

The max_value & min_value Errors

The max_value and min_value errors apply for the Padlock and the Input element.

For the padlock element a max_value validation error is returned if the server finds a value inside the numbers array which is greater than (padlock.rows * padock.columns) -1. A min_value validation error is returned if the server finds a value inside the numbers array which is lower than 0.

For the input element the max_value and/or min_value validation error is returned if the specified max_value and/or min_value properties of the input element have been disregarded.

The allow_selected_max & allow_selected_min Errors

The allow_selected_max and allow_selected_min apply for the Choice element.

The errors will be set to true if the allow_selected.min and/or allow_selected.max attribute of the element have been disregarded.

Disabled Options

The option_disabled error applies for the elements Choice and Switchable.

An option_disabled validation error is returned if the server finds a selected option which is marked as disabled.

Invalid Options

The valid_options error applies for the elements Choice and Switchable.

A valid_options validation error is returned if the selected option is not one of the choosable options.

Example

{
    "required": "true",
}

{
    "min_length": "true",
    "pattern": "true",
}