---
title: "Validating Models"
version: "3.4"
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.phalcon.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Validating Models

## Validating Data Integrity
[Phalcon\Mvc\Model](/3.4/api/phalcon_mvc_model/) provides several events to validate data and implement business rules. The special `validation` event allows us to call built-in validators over the record. Phalcon exposes a few built-in validators that can be used at this stage of validation.

The following example shows how to use it:

```php
<?php

namespace Store\Toys;

use Phalcon\Mvc\Model;
use Phalcon\Validation;
use Phalcon\Validation\Validator\Uniqueness;
use Phalcon\Validation\Validator\InclusionIn;

class Robots extends Model
{
public function validation()
{
    $validator = new Validation();

    $validator->add(
        'type',
        new InclusionIn(
            [
                'domain' => [
                    'Mechanical',
                    'Virtual',
                ]
            ]
        )
    );

    $validator->add(
        'name',
        new Uniqueness(
            [
                'message' => 'The robot name must be unique',
            ]
        )
    );

    return $this->validate($validator);
}
}
```

The above example performs a validation using the built-in validator 'InclusionIn'. It checks the value of the field `type` in a domain list. If the value is not included in the method then the validator will fail and return false.

:::warning[NOTE]
For more information on validators, see the [Validation documentation](/3.4/validation/)
:::

The idea of creating validators is make them reusable between several models. A validator can also be as simple as:

```php
<?php

namespace Store\Toys;

use Phalcon\Mvc\Model;
use Phalcon\Mvc\Model\Message;

class Robots extends Model
{
public function validation()
{
    if ($this->type === 'Old') {
        $message = new Message(
            'Sorry, old robots are not allowed anymore',
            'type',
            'MyType'
        );

        $this->appendMessage($message);

        return false;
    }

    return true;
}
}
```

## Validation Messages
[Phalcon\Mvc\Model](/3.4/api/phalcon_mvc_model/) has a messaging subsystem that provides a flexible way to output or store the validation messages generated during the insert/update processes.

Each message is an instance of [Phalcon\Mvc\Model\Message](/3.4/api/phalcon_mvc_model_message/) and the set of messages generated can be retrieved with the `getMessages()` method. Each message provides extended information like the field name that generated the message or the message type:

```php
<?php

if ($robot->save() === false) {
$messages = $robot->getMessages();

foreach ($messages as $message) {
    echo 'Message: ', $message->getMessage();
    echo 'Field: ', $message->getField();
    echo 'Type: ', $message->getType();
}
}
```

[Phalcon\Mvc\Model](/3.4/api/phalcon_mvc_model/) can generate the following types of validation messages:

| Type                   | Description                                                                                                                        |
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| `PresenceOf`           | Generated when a field with a non-null attribute on the database is trying to insert/update a null value                           |
| `ConstraintViolation`  | Generated when a field part of a virtual foreign key is trying to insert/update a value that doesn't exist in the referenced model |
| `InvalidValue`         | Generated when a validator failed because of an invalid value                                                                      |
| `InvalidCreateAttempt` | Produced when a record is attempted to be created but it already exists                                                            |
| `InvalidUpdateAttempt` | Produced when a record is attempted to be updated but it doesn't exist                                                             |

The `getMessages()` method can be overridden in a model to replace/translate the default messages generated automatically by the ORM:

```php
<?php

namespace Store\Toys;

use Phalcon\Mvc\Model;

class Robots extends Model
{
public function getMessages()
{
    $messages = [];

    foreach (parent::getMessages() as $message) {
        switch ($message->getType()) {
            case 'InvalidCreateAttempt':
                $messages[] = 'The record cannot be created because it already exists';
                break;

            case 'InvalidUpdateAttempt':
                $messages[] = "The record cannot be updated because it doesn't exist";
                break;

            case 'PresenceOf':
                $messages[] = 'The field ' . $message->getField() . ' is mandatory';
                break;
        }
    }

    return $messages;
}
}
```

## Validation Failed Events
Another type of events are available when the data validation process finds any inconsistency:

| Operation                | Name                 | Explanation                                                            |
| ------------------------ | -------------------- | ---------------------------------------------------------------------- |
| Insert or Update         | `notSaved`           | Triggered when the `INSERT` or `UPDATE` operation fails for any reason |
| Insert, Delete or Update | `onValidationFails`  | Triggered when any data manipulation operation fails                   |

Source: https://docs.phalcon.io/3.4/db-models-validation/index.mdx