Validating form fields

When creating forms, the fields described in the Data types section are used. Regardless of the method of creating a form (from a model / without a model), the fields have properties that are set by default.

• for all field types: required, must_match
• char: regexp, captcha, length, min_length, max_length, min_max_length, unique
• int, float: zero_allowed, positive
• email, phone, url, redirect: format, as well as properties inherited from char
• text: properties inherited from char
• file, image, multi_images: allowed_extensions, allowed_mime_types, as an array

Based on these properties, the initial validation of form fields occurs using the validate().

//Set the fields of the future form
$fields = [
    ['Name', 'char', 'name', ['max_length' => 20]],
    ['Coupon code', 'char', 'coupon', ['length' => 8]],
    ['About me', 'text', 'about'],
    ['Email', 'email', 'email', ['unique' => true]],
    ['Password', 'password', 'password', ['min_length' => 5]],
    ['Repeat password', 'password', 'password_repeat', ['must_match' => 'password']],
    ['Captcha', 'char', 'code', ['captcha' => 'extra/captcha-simple']]
];

//Create a form object
$form = new Form($fields);

//Set required fields
$form -> setRequiredFields(['name', 'password', 'password_repeat', 'code']);

//Add another field
$form -> addField(['Photo', 'image', 'photo', ['files_folder' => 'uploads']));

//Get data from POST and validate
$form -> submit() -> validate();

//We can check the form state (usually in AJAX)
Debug::pre($form -> getState());

//If the form is valid
if($form -> isSubmitted() && $form -> isValid())
{
    ...
}

//Selective validation of fields
$form -> submit() -> validate(['name', 'coupon']);

//Adding an error to the form
$form -> addError('Please enter a more detailed description of the activity.');

//Manually setting the field value
$form -> about = 'No activity description specified.';

Thus, when checking fields, the max_length, length, required, min_length, must_match rules will be applied for the corresponding fields. Based on the specific situation, you can redefine the specified rules for fields or assign new ones.

Adding a new rule

To add a new rule, you need to call the addRule() method with an array of parameters in the following order:

1. field name, can also be an array or the '*' symbol for all fields
2. property name, characteristic of the data type to which this field belongs
3. property value to check (if you pass the value in the form '->', then only the message will be changed and the rule will remain the same, this is convenient for changing the error message for fields checked by regular expressions: int, float, email, phone, url, redirect
4. message that is displayed if the check is not passed, if this parameter is not passed, a system message for this rule will be displayed

//Making a field mandatory
$form -> addRule('cupon', 'required', true, 'You must enter a coupon code to register.');

//Making all fields mandatory
$form -> addRule('*', 'required', true, 'This field must be filled in.');

//Adding a regular expression check
$form -> addRule('coupon', 'regexp', '/^d+$/', 'The coupon code can only contain numbers.');

//Setting a minimum length for the entered text
$form -> addRule('about', 'min_length', 200, 'You must have at least 200 characters to tell us about yourself.');

//Setting a maximum length for several fields
$form -> addRule(['name', 'cupon', 'email'], 'max_length', 100, 'The field length must not exceed 100 characters.');

//Set a new message when checking for email address uniqueness
//(replaces the default message)
$form -> addRule('email', 'unique', true, 'This email address is already in use by another user.');

//New message when checking for email address correctness
$form -> addRule('email', 'format', '/^[-a-z0-9_.]+@[-a-z0-9_.]+.[a-z]{2,5}$/i', 'Enter a valid email');

//New message (short format) when checking for email address correctness
$form -> addRule('email', 'format', '->', 'Enter a valid email');

//Check for repeated password entry
$form -> addRule('password_repeat', 'must_match', 'password', 'Incorrect password repeat');

//Restriction on uploaded file types
$form -> addRule('photo', 'allowed_extensions', ['png', 'jpg'], 'Select a png or jpg file');

Removing a rule

To remove a rule, you must pass 2 arguments to the removeRule() method: the name of the field and the name of the rule to be removed.

//Do not check the minimum length
$form -> removeRule('name', 'max_length');

//The field is not required to fill
$form -> removeRule('coupon', 'required');

//Fields are not required to fill
$form -> removeRule(['name', 'email'], 'required');

//Remove email uniqueness check
$form -> removeRule('email', 'unique');

//Remove all fields from checking for maximum length
$form -> removeRule('*', 'max_length');

Displaying validation errors

//Entering POST data into the form and validation
$form -> submit() -> validate();

//Get an array of errors
$errors = $form -> getErrors();

//Add an error to the general list
$form -> addError('Error text.')

//Add an error for a specific field
$form -> addError('Error text.', 'content');

//Output all errors in one list
echo $form -> displayErrors();

//Output the form with errors located next to the fields
echo $form -> setDisplayWithErrors() -> display();