Using CodeIgniter’s Model

Models

The CodeIgniter’s Model provides convenience features and additional functionality that people commonly use to make working with a single table in your database more convenient.

It comes out of the box with helper methods for much of the standard ways you would need to interact with a database table, including finding records, updating records, deleting records, and more.

Accessing Models

Models are typically stored in the app/Models directory. They should have a namespace that matches their location within the directory, like namespace App\Models.

You can access models within your classes by creating a new instance or using the model() helper function.

<?php

// Create a new class manually.
$userModel = new \App\Models\UserModel();

// Create a shared instance of the model.
$userModel = model('UserModel');
// or
$userModel = model('App\Models\UserModel');
// or
$userModel = model(\App\Models\UserModel::class);

// Create a new class with the model() function.
$userModel = model('UserModel', false);

// Create shared instance with a supplied database connection.
$db        = db_connect('custom');
$userModel = model('UserModel', true, $db);

The model() uses Factories::models() internally. See Loading Classes for details on the first parameter.

CodeIgniter’s Model

CodeIgniter does provide a model class that has a few nice features, including:

• automatic database connection

• basic CRUD methods

• in-model validation

• automatic pagination

• and more

This class provides a solid base from which to build your own models, allowing you to rapidly build out your application’s model layer.

Creating Your Model

To take advantage of CodeIgniter’s model, you would simply create a new model class that extends CodeIgniter\Model:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    // ...
}

This empty class provides convenient access to the database connection, the Query Builder, and a number of additional convenience methods.

initialize()

Should you need additional setup in your model you may extend the initialize() method which will be run immediately after the Model’s constructor. This allows you to perform extra steps without repeating the constructor parameters, for example extending other models:

<?php

namespace App\Models;

use Modules\Authentication\Models\UserAuthModel;

class UserModel extends UserAuthModel
{
    // ...

    /**
     * Called during initialization. Appends
     * our custom field to the module's model.
     */
    protected function initialize()
    {
        $this->allowedFields[] = 'middlename';
    }
}

Connecting to the Database

When the class is first instantiated, if no database connection instance is passed to the constructor, and if you don’t set the $DBGroup property on your model class, it will automatically connect to the default database group, as set in the database configuration.

You can modify which group is used on a per-model basis by adding the $DBGroup property to your class. This ensures that within the model any references to $this->db are made through the appropriate connection.

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    protected $DBGroup = 'group_name';

    // ...
}

You would replace “group_name” with the name of a defined database group from the database configuration file.

Configuring Your Model

The model class has some configuration options that can be set to allow the class’ methods to work seamlessly for you. The first two are used by all of the CRUD methods to determine what table to use and how we can find the required records:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    protected $table      = 'users';
    protected $primaryKey = 'id';

    protected $useAutoIncrement = true;

    protected $returnType     = 'array';
    protected $useSoftDeletes = true;

    protected $allowedFields = ['name', 'email'];

    protected bool $allowEmptyInserts = false;
    protected bool $updateOnlyChanged = true;

    // Dates
    protected $useTimestamps = false;
    protected $dateFormat    = 'datetime';
    protected $createdField  = 'created_at';
    protected $updatedField  = 'updated_at';
    protected $deletedField  = 'deleted_at';

    // Validation
    protected $validationRules      = [];
    protected $validationMessages   = [];
    protected $skipValidation       = false;
    protected $cleanValidationRules = true;

    // Callbacks
    protected $allowCallbacks = true;
    protected $beforeInsert   = [];
    protected $afterInsert    = [];
    protected $beforeUpdate   = [];
    protected $afterUpdate    = [];
    protected $beforeFind     = [];
    protected $afterFind      = [];
    protected $beforeDelete   = [];
    protected $afterDelete    = [];
}

$table

Specifies the database table that this model primarily works with. This only applies to the built-in CRUD methods. You are not restricted to using only this table in your own queries.

$primaryKey

This is the name of the column that uniquely identifies the records in this table. This does not necessarily have to match the primary key that is specified in the database, but is used with methods like find() to know what column to match the specified value to.

Note

All Models must have a primaryKey specified to allow all of the features to work as expected.

$useAutoIncrement

Specifies if the table uses an auto-increment feature for $primaryKey. If set to false then you are responsible for providing primary key value for every record in the table. This feature may be handy when we want to implement 1:1 relation or use UUIDs for our model. The default value is true.

Note

If you set $useAutoIncrement to false, then make sure to set your primary key in the database to unique. This way you will make sure that all of Model’s features will still work the same as before.

$returnType

The Model’s find*() methods will take a step of work away from you and automatically return the resulting data, instead of the Result object.

This setting allows you to define the type of data that is returned. Valid values are ‘array’ (the default), ‘object’, or the fully qualified name of a class that can be used with the Result object’s getCustomResultObject() method.

Using the special ::class constant of the class will allow most IDEs to auto-complete the name and allow functions like refactoring to better understand your code.

$useSoftDeletes

If true, then any delete() method calls will set deleted_at in the database, instead of actually deleting the row. This can preserve data when it might be referenced elsewhere, or can maintain a “recycle bin” of objects that can be restored, or even simply preserve it as part of a security trail. If true, the find*() methods will only return non-deleted rows, unless the withDeleted() method is called prior to calling the find*() method.

This requires either a DATETIME or INTEGER field in the database as per the model’s $dateFormat setting. The default field name is deleted_at however this name can be configured to any name of your choice by using $deletedField property.

Important

The deleted_at field in the database must be nullable.

$allowedFields

This array should be updated with the field names that can be set during save(), insert(), or update() methods. Any field names other than these will be discarded. This helps to protect against just taking input from a form and throwing it all at the model, resulting in potential mass assignment vulnerabilities.

Note

The $primaryKey field should never be an allowed field.

$allowEmptyInserts

New in version 4.3.0.

Whether to allow inserting empty data. The default value is false, meaning that if you try to insert empty data, DataException with “There is no data to insert.” will raise.

You may also change this setting with the allowEmptyInserts() method.

$updateOnlyChanged

New in version 4.5.0.

Whether to update Entity’s only changed fields. The default value is true, meaning that only changed field data is used when updating to the database. So if you try to update an Entity without changes, DataException with “There is no data to update.” will raise.

Setting this property to false will ensure that all allowed fields of an Entity are submitted to the database and updated at any time.

$casts

New in version 4.5.0.

This allows you to convert data retrieved from a database into the appropriate PHP type. This option should be an array where the key is the name of the field, and the value is the data type. See Model Field Casting for details.

Dates

$useTimestamps

This boolean value determines whether the current date is automatically added to all inserts and updates. If true, will set the current time in the format specified by $dateFormat. This requires that the table have columns named created_at, updated_at and deleted_at in the appropriate data type. See also $createdField, $updatedField, and $deletedField.

$dateFormat

This value works with $useTimestamps and $useSoftDeletes to ensure that the correct type of date value gets inserted into the database. By default, this creates DATETIME values, but valid options are: 'datetime', 'date', or 'int' (a UNIX timestamp). Using $useSoftDeletes or $useTimestamps with an invalid or missing $dateFormat will cause an exception.

$createdField

Specifies which database field to use for data record create timestamp. Set to an empty string ('') to avoid updating it (even if $useTimestamps is enabled).

$updatedField

Specifies which database field should use for keep data record update timestamp. Set to an empty string ('') to avoid updating it (even $useTimestamps is enabled).

$deletedField

Specifies which database field to use for soft deletions. See $useSoftDeletes.

Validation

$validationRules

Contains either an array of validation rules as described in How to Save Your Rules or a string containing the name of a validation group, as described in the same section. See also Setting Validation Rules.

$validationMessages

Contains an array of custom error messages that should be used during validation, as described in Setting Custom Error Messages. See also Setting Validation Rules.

$skipValidation

Whether validation should be skipped during all inserts and updates. The default value is false, meaning that data will always attempt to be validated. This is primarily used by the skipValidation() method, but may be changed to true so this model will never validate.

$cleanValidationRules

Whether validation rules should be removed that do not exist in the passed data. This is used in updates. The default value is true, meaning that validation rules for the fields that are not present in the passed data will be (temporarily) removed before the validation. This is to avoid validation errors when updating only some fields.

You can also change the value by the cleanRules() method.

Note

Prior to v4.2.7, $cleanValidationRules did not work due to a bug.

Callbacks

$allowCallbacks

Whether the callbacks defined below should be used. See Model Events.

$beforeInsert

$afterInsert

$beforeUpdate

$afterUpdate

$beforeFind

$afterFind

$beforeDelete

$afterDelete

$beforeInsertBatch

$afterInsertBatch

$beforeUpdateBatch

$afterUpdateBatch

These arrays allow you to specify callback methods that will be run on the data at the time specified in the property name. See Model Events.

Model Field Casting

New in version 4.5.0.

When retrieving data from a database, data of integer type may be converted to string type in PHP. You may also want to convert date/time data into a Time object in PHP.

Model Field Casting allows you to convert data retrieved from a database into the appropriate PHP type.

Important

If you use this feature with the Entity, do not use Entity Property Casting. Using both casting at the same time does not work.

Entity Property Casting works at (1)(4), but this casting works at (2)(3):

[App Code] --- (1) --> [Entity] --- (2) --> [Database]
[App Code] <-- (4) --- [Entity] <-- (3) --- [Database]

When using this casting, Entity will have correct typed PHP values in the attributes. This behavior is completely different from the previous behavior. Do not expect the attributes hold raw data from database.

Defining Data Types

The $casts property sets its definition. This option should be an array where the key is the name of the field, and the value is the data type:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    // ...
    protected array $casts = [
        'id'        => 'int',
        'birthdate' => '?datetime',
        'hobbies'   => 'json-array',
        'active'    => 'int-bool',
    ];
    // ...
}

Data Types

The following types are provided by default. Add a question mark at the beginning of type to mark the field as nullable, i.e., ?int, ?datetime.

Type	PHP Value Type	DB Column Type
int	int	int type
float	float	float (numeric) type
bool	bool	bool/int/string type
int-bool	bool	int type (1 or 0)
array	array	string type (serialized)
csv	array	string type (CSV)
json	stdClass	json/string type
json-array	array	json/string type
datetime	Time	datetime type
timestamp	Time	int type (UNIX timestamp)
uri	URI	string type

csv

Casting as csv uses PHP’s internal implode() and explode() functions and assumes all values are string-safe and free of commas. For more complex data casts try array or json.

datetime

You can pass a parameter like datetime[ms] for date/time with milliseconds, or datetime[us] for date/time with microseconds.

The datetime format is set in the dateFormat array of the database configuration in the app/Config/Database.php file.

Custom Casting

You can define your own conversion types.

Creating Custom Handlers

At first you need to create a handler class for your type. Let’s say the class will be located in the app/Models/Cast directory:

<?php

namespace App\Models\Cast;

use CodeIgniter\DataCaster\Cast\BaseCast;
use InvalidArgumentException;

// The class must inherit the CodeIgniter\DataCaster\Cast\BaseCast class
class CastBase64 extends BaseCast
{
    public static function get(
        mixed $value,
        array $params = [],
        ?object $helper = null
    ): string {
        if (! is_string($value)) {
            self::invalidTypeValueError($value);
        }

        $decoded = base64_decode($value, true);

        if ($decoded === false) {
            throw new InvalidArgumentException('Cannot decode: ' . $value);
        }

        return $decoded;
    }

    public static function set(
        mixed $value,
        array $params = [],
        ?object $helper = null
    ): string {
        if (! is_string($value)) {
            self::invalidTypeValueError($value);
        }

        return base64_encode($value);
    }
}

If you don’t need to change values when getting or setting a value. Then just don’t implement the appropriate method:

<?php

namespace App\Models\Cast;

use CodeIgniter\DataCaster\Cast\BaseCast;
use InvalidArgumentException;

class CastBase64 extends BaseCast
{
    public static function get(
        mixed $value,
        array $params = [],
        ?object $helper = null
    ): string {
        if (! is_string($value)) {
            self::invalidTypeValueError($value);
        }

        $decoded = base64_decode($value, true);

        if ($decoded === false) {
            throw new InvalidArgumentException('Cannot decode: ' . $value);
        }

        return $decoded;
    }
}

Registering Custom Handlers

Now you need to register it:

<?php

namespace App\Models;

use App\Models\Cast\CastBase64;
use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    // Specify the type for the field
    protected array $casts = [
        'column1' => 'base64',
    ];

    // Bind the type to the handler
    protected array $castHandlers = [
        'base64' => CastBase64::class,
    ];

    // ...
}

Parameters

In some cases, one type is not enough. In this situation, you can use additional parameters. Additional parameters are indicated in square brackets and listed with a comma like type[param1, param2].

<?php

namespace App\Models;

use App\Models\Cast\SomeHandler;
use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    // Define a type with parameters
    protected array $casts = [
        'column1' => 'class[App\SomeClass, param2, param3]',
    ];

    // Bind the type to the handler
    protected array $castHandlers = [
        'class' => SomeHandler::class,
    ];

    // ...
}

<?php

namespace App\Models\Cast;

use CodeIgniter\DataCaster\Cast\BaseCast;

class SomeHandler extends BaseCast
{
    public static function get(
        mixed $value,
        array $params = [],
        ?object $helper = null
    ): mixed {
        var_dump($params);
        /*
         * Output:
         * array(3) {
         *   [0]=>
         *   string(13) "App\SomeClass"
         *   [1]=>
         *   string(6) "param2"
         *   [2]=>
         *   string(6) "param3"
         * }
         */
    }
}

Note

If the casting type is marked as nullable like ?bool and the passed value is not null, then the parameter with the value nullable will be passed to the casting type handler. If casting type has predefined parameters, then nullable will be added to the end of the list.

Working with Data

Finding Data

Several functions are provided for doing basic CRUD work on your tables, including find(), insert(), update(), delete() and more.

find()

Returns a single row where the primary key matches the value passed in as the first parameter:

<?php

$user = $userModel->find($user_id);

The value is returned in the format specified in $returnType.

You can specify more than one row to return by passing an array of primaryKey values instead of just one:

<?php

$users = $userModel->find([1, 2, 3]);

Note

If no parameters are passed in, find() will return all rows in that model’s table, effectively acting like findAll(), though less explicit.

findColumn()

Returns null or an indexed array of column values:

<?php

$user = $userModel->findColumn($column_name);

$column_name should be a name of single column else you will get the DataException.

findAll()

Returns all results:

<?php

$users = $userModel->findAll();

This query may be modified by interjecting Query Builder commands as needed prior to calling this method:

<?php

$users = $userModel->where('active', 1)->findAll();

You can pass in a limit and offset values as the first and second parameters, respectively:

<?php

$users = $userModel->findAll($limit, $offset);

first()

Returns the first row in the result set. This is best used in combination with the query builder.

<?php

$user = $userModel->where('deleted', 0)->first();

withDeleted()

If $useSoftDeletes is true, then the find*() methods will not return any rows where deleted_at IS NOT NULL. To temporarily override this, you can use the withDeleted() method prior to calling the find*() method.

<?php

// Only gets non-deleted rows (deleted = 0)
$activeUsers = $userModel->findAll();

// Gets all rows
$allUsers = $userModel->withDeleted()->findAll();

onlyDeleted()

Whereas withDeleted() will return both deleted and not-deleted rows, this method modifies the next find*() methods to return only soft deleted rows:

<?php

$deletedUsers = $userModel->onlyDeleted()->findAll();

Saving Data

insert()

The first parameter is an associative array of data to create a new row of data in the database. If an object is passed instead of an array, it will attempt to convert it to an array.

The array’s keys must match the name of the columns in the $table, while the array’s values are the values to save for that key.

The optional second parameter is of type boolean, and if it is set to false, the method will return a boolean value, which indicates the success or failure of the query.

You can retrieve the last inserted row’s primary key using the getInsertID() method.

<?php

$data = [
    'username' => 'darth',
    'email'    => 'd.vader@theempire.com',
];

// Inserts data and returns inserted row's primary key
$userModel->insert($data);

// Inserts data and returns true on success and false on failure
$userModel->insert($data, false);

// Returns inserted row's primary key
$userModel->getInsertID();

allowEmptyInserts()

New in version 4.3.0.

You can use allowEmptyInserts() method to insert empty data. The Model throws an exception when you try to insert empty data by default. But if you call this method, the check will no longer be performed.

<?php

$userModel->allowEmptyInserts()->insert([]);

You may also change this setting with the $allowEmptyInserts property.

You can enable the check again by calling allowEmptyInserts(false).

update()

Updates an existing record in the database. The first parameter is the $primaryKey of the record to update. An associative array of data is passed into this method as the second parameter. The array’s keys must match the name of the columns in a $table, while the array’s values are the values to save for that key:

<?php

$data = [
    'username' => 'darth',
    'email'    => 'd.vader@theempire.com',
];

$userModel->update($id, $data);

Important

Since v4.3.0, this method raises a DatabaseException if it generates an SQL statement without a WHERE clause. In previous versions, if it is called without $primaryKey specified and an SQL statement was generated without a WHERE clause, the query would still execute and all records in the table would be updated.

Multiple records may be updated with a single call by passing an array of primary keys as the first parameter:

<?php

$data = [
    'active' => 1,
];

$userModel->update([1, 2, 3], $data);

When you need a more flexible solution, you can leave the parameters empty and it functions like the Query Builder’s update command, with the added benefit of validation, events, etc:

<?php

$userModel
    ->whereIn('id', [1, 2, 3])
    ->set(['active' => 1])
    ->update();

save()

This is a wrapper around the insert() and update() methods that handle inserting or updating the record automatically, based on whether it finds an array key matching the primary key value:

<?php

// Defined as a model property
$primaryKey = 'id';

// Does an insert()
$data = [
    'username' => 'darth',
    'email'    => 'd.vader@theempire.com',
];

$userModel->save($data);

// Performs an update, since the primary key, 'id', is found.
$data = [
    'id'       => 3,
    'username' => 'darth',
    'email'    => 'd.vader@theempire.com',
];
$userModel->save($data);

The save method also can make working with custom class result objects much simpler by recognizing a non-simple object and grabbing its public and protected values into an array, which is then passed to the appropriate insert or update method. This allows you to work with Entity classes in a very clean way. Entity classes are simple classes that represent a single instance of an object type, like a user, a blog post, a job, etc. This class is responsible for maintaining the business logic surrounding the object itself, like formatting elements in a certain way, etc. They shouldn’t have any idea about how they are saved to the database. At their simplest, they might look like this:

<?php

namespace App\Entities;

class Job
{
    protected $id;
    protected $name;
    protected $description;

    public function __get($key)
    {
        if (property_exists($this, $key)) {
            return $this->{$key};
        }
    }

    public function __set($key, $value)
    {
        if (property_exists($this, $key)) {
            $this->{$key} = $value;
        }
    }
}

A very simple model to work with this might look like:

<?php

namespace App\Models;

use CodeIgniter\Model;

class JobModel extends Model
{
    protected $table         = 'jobs';
    protected $returnType    = \App\Entities\Job::class;
    protected $allowedFields = [
        'name', 'description',
    ];
}

This model works with data from the jobs table, and returns all results as an instance of App\Entities\Job. When you need to persist that record to the database, you will need to either write custom methods, or use the model’s save() method to inspect the class, grab any public and private properties, and save them to the database:

<?php

// Retrieve a Job instance
$job = $model->find(15);

// Make some changes
$job->name = 'Foobar';

// Save the changes
$model->save($job);

Note

If you find yourself working with Entities a lot, CodeIgniter provides a built-in Entity class that provides several handy features that make developing Entities simpler.

Saving Dates

New in version 4.5.0.

When saving data, if you pass Time instances, they are converted to strings with the format defined in dateFormat['datetime'] and dateFormat['date'] in the database configuration.

Note

Prior to v4.5.0, the date/time formats were hard coded as Y-m-d H:i:s and Y-m-d in the Model class.

Deleting Data

delete()

Takes a primary key value as the first parameter and deletes the matching record from the model’s table:

<?php

$userModel->delete(12);

If the model’s $useSoftDeletes value is true, this will update the row to set deleted_at to the current date and time. You can force a permanent delete by setting the second parameter as true.

An array of primary keys can be passed in as the first parameter to delete multiple records at once:

<?php

$userModel->delete([1, 2, 3]);

If no parameters are passed in, will act like the Query Builder’s delete method, requiring a where call previously:

<?php

$userModel->where('id', 12)->delete();

purgeDeleted()

Cleans out the database table by permanently removing all rows that have ‘deleted_at IS NOT NULL’.

<?php

$userModel->purgeDeleted();

In-Model Validation

Warning

In-Model validation is performed just before data is stored in the database. Prior to that point, the data has not yet been validated. Processing user-input data prior to validation may introduce vulnerabilities.

Validating Data

The Model class provides a way to automatically have all data validated prior to saving to the database with the insert(), update(), or save() methods.

Important

When you update data, by default, the validation in the model class only validates provided fields. This is to avoid validation errors when updating only some fields.

However, this means that not all validation rules you set will be checked during updates. Thus, incomplete data may pass the validation.

For example, required* rules or is_unique rule that require the values of other fields may not work as expected.

To avoid such glitches, this behavior can be changed by configuration. See $cleanValidationRules for details.

Setting Validation Rules

The first step is to fill out the $validationRules class property with the fields and rules that should be applied.

Note

You can see the list of built-in Validation rules in Available Rules.

If you have custom error message that you want to use, place them in the $validationMessages array:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    // ...

    protected $validationRules = [
        'username'     => 'required|max_length[30]|alpha_numeric_space|min_length[3]',
        'email'        => 'required|max_length[254]|valid_email|is_unique[users.email]',
        'password'     => 'required|max_length[255]|min_length[8]',
        'pass_confirm' => 'required_with[password]|max_length[255]|matches[password]',
    ];
    protected $validationMessages = [
        'email' => [
            'is_unique' => 'Sorry. That email has already been taken. Please choose another.',
        ],
    ];
}

If you’d rather organize your rules and error messages within the Validation Config File, you can do that and simply set $validationRules to the name of the validation rule group you created:

<?php

namespace App\Models;

use CodeIgniter\Model;

class UserModel extends Model
{
    // ...

    protected $validationRules = 'users';
}

The other way to set the validation rules to fields by functions,

class CodeIgniter\Model

CodeIgniter\Model::setValidationRule($field, $fieldRules)

Parameters:

• $field (string) –

• $fieldRules (array) –

This function will set the field validation rules.

Usage example:

<?php

$fieldName  = 'username';
$fieldRules = 'required|max_length[30]|alpha_numeric_space|min_length[3]';

$model->setValidationRule($fieldName, $fieldRules);

CodeIgniter\Model::setValidationRules($validationRules)

Parameters:

• $validationRules (array) –

This function will set the validation rules.

Usage example:

<?php

$validationRules = [
    'username' => 'required|max_length[30]|alpha_numeric_space|min_length[3]',
    'email'    => [
        'rules'  => 'required|max_length[254]|valid_email|is_unique[users.email]',
        'errors' => [
            'required' => 'We really need your email.',
        ],
    ],
];
$model->setValidationRules($validationRules);

The other way to set the validation message to fields by functions,

CodeIgniter\Model::setValidationMessage($field, $fieldMessages)

Parameters:

• $field (string) –

• $fieldMessages (array) –

This function will set the field wise error messages.

Usage example:

<?php

$fieldName              = 'name';
$fieldValidationMessage = [
    'required' => 'Your name is required here',
];
$model->setValidationMessage($fieldName, $fieldValidationMessage);

CodeIgniter\Model::setValidationMessages($fieldMessages)

Parameters:

• $fieldMessages (array) –

This function will set the field messages.

Usage example:

<?php

$fieldValidationMessage = [
    'name' => [
        'required'   => 'Your baby name is missing.',
        'min_length' => 'Too short, man!',
    ],
];
$model->setValidationMessages($fieldValidationMessage);

Getting Validation Result

Now, whenever you call the insert(), update(), or save() methods, the data will be validated. If it fails, the model will return boolean false.

Getting Validation Errors

You can use the errors() method to retrieve the validation errors:

<?php

if ($model->save($data) === false) {
    return view('updateUser', ['errors' => $model->errors()]);
}

This returns an array with the field names and their associated errors that can be used to either show all of the errors at the top of the form, or to display them individually:

<?php if (! empty($errors)): ?>
    <div class="alert alert-danger">
    <?php foreach ($errors as $field => $error): ?>
        <p><?= esc($error) ?></p>
    <?php endforeach ?>
    </div>
<?php endif ?>

Retrieving Validation Rules

You can retrieve a model’s validation rules by accessing its validationRules property:

<?php

$rules = $model->validationRules;

You can also retrieve just a subset of those rules by calling the accessor method directly, with options:

<?php

$rules = $model->getValidationRules($options);

The $options parameter is an associative array with one element, whose key is either 'except' or 'only', and which has as its value an array of fieldnames of interest:

<?php

// get the rules for all but the "username" field
$rules = $model->getValidationRules(['except' => ['username']]);
// get the rules for only the "city" and "state" fields
$rules = $model->getValidationRules(['only' => ['city', 'state']]);

Validation Placeholders

The model provides a simple method to replace parts of your rules based on data that’s being passed into it. This sounds fairly obscure but can be especially handy with the is_unique validation rule. Placeholders are simply the name of the field (or array key) that was passed in as $data surrounded by curly brackets. It will be replaced by the value of the matched incoming field. An example should clarify this:

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $validationRules = [
        'id'    => 'max_length[19]|is_natural_no_zero',
        'email' => 'required|max_length[254]|valid_email|is_unique[users.email,id,{id}]',
    ];
}

Note

Since v4.3.5, you must set the validation rules for the placeholder field (id).

In this set of rules, it states that the email address should be unique in the database, except for the row that has an id matching the placeholder’s value. Assuming that the form POST data had the following:

<?php

$_POST = [
    'id'    => 4,
    'email' => 'foo@example.com',
];

then the {id} placeholder would be replaced with the number 4, giving this revised rule:

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $validationRules = [
        'id'    => 'max_length[19]|is_natural_no_zero',
        'email' => 'required|max_length[254]|valid_email|is_unique[users.email,id,4]',
    ];
}

So it will ignore the row in the database that has id=4 when it verifies the email is unique.

Note

Since v4.3.5, if the placeholder (id) value does not pass the validation, the placeholder would not be replaced.

This can also be used to create more dynamic rules at runtime, as long as you take care that any dynamic keys passed in don’t conflict with your form data.

Protecting Fields

To help protect against Mass Assignment Attacks, the Model class requires that you list all of the field names that can be changed during inserts and updates in the $allowedFields class property. Any data provided in addition to these will be removed prior to hitting the database. This is great for ensuring that timestamps, or primary keys do not get changed.

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $allowedFields = ['name', 'email', 'address'];
}

Occasionally, you will find times where you need to be able to change these elements. This is often during testing, migrations, or seeds. In these cases, you can turn the protection on or off:

<?php

$model->protect(false)
    ->insert($data)
    ->protect(true);

Runtime Return Type Changes

You can specify the format that data should be returned as when using the find*() methods as the class property, $returnType. There may be times that you would like the data back in a different format, though. The Model provides methods that allow you to do just that.

Note

These methods only change the return type for the next find*() method call. After that, it is reset to its default value.

asArray()

Returns data from the next find*() method as associative arrays:

<?php

$users = $userModel->asArray()->where('status', 'active')->findAll();

asObject()

Returns data from the next find*() method as standard objects or custom class instances:

<?php

// Return as standard objects
$users = $userModel->asObject()->where('status', 'active')->findAll();

// Return as custom class instances
$users = $userModel->asObject('User')->where('status', 'active')->findAll();

Processing Large Amounts of Data

Sometimes, you need to process large amounts of data and would run the risk of running out of memory. To make this simpler, you may use the chunk() method to get smaller chunks of data that you can then do your work on. The first parameter is the number of rows to retrieve in a single chunk. The second parameter is a Closure that will be called for each row of data.

This is best used during cronjobs, data exports, or other large tasks.

<?php

$userModel->chunk(100, static function ($data) {
    // do something.
    // $data is a single row of data.
});

Working with Query Builder

Getting Query Builder for the Model’s Table

CodeIgniter Model has one instance of the Query Builder for that model’s database connection. You can get access to the shared instance of the Query Builder any time you need it:

<?php

$builder = $userModel->builder();

This builder is already set up with the model’s $table.

Note

Once you get the Query Builder instance, you can call methods of the Query Builder. However, since Query Builder is not a Model, you cannot call methods of the Model.

Getting Query Builder for Another Table

If you need access to another table, you can get another instance of the Query Builder. Pass the table name in as a parameter, but be aware that this will not return a shared instance:

<?php

$groupBuilder = $userModel->builder('groups');

Mixing Methods of Query Builder and Model

You can also use Query Builder methods and the Model’s CRUD methods in the same chained call, allowing for very elegant use:

<?php

$users = $userModel->where('status', 'active')
    ->orderBy('last_login', 'asc')
    ->findAll();

In this case, it operates on the shared instance of the Query Builder held by the model.

Important

The Model does not provide a perfect interface to the Query Builder. The Model and the Query Builder are separate classes with different purposes. They should not be expected to return the same data.

If the Query Builder returns a result, it is returned as is. In that case, the result may be different from the one returned by the model’s method and may not be what was expected. The model’s events are not triggered.

To prevent unexpected behavior, do not use Query Builder methods that return results and specify the model’s method at the end of the method chaining.

Note

You can also access the model’s database connection seamlessly:

<?php

$user_name = $userModel->escape($name);

Model Events

There are several points within the model’s execution that you can specify multiple callback methods to run. These methods can be used to normalize data, hash passwords, save related entities, and much more.

The following points in the model’s execution can be affected, each through a class property:

• $beforeInsert, $afterInsert

• $beforeUpdate, $afterUpdate

• $beforeFind, $afterFind

• $beforeDelete, $afterDelete

• $beforeInsertBatch, $afterInsertBatch

• $beforeUpdateBatch, $afterUpdateBatch

Note

$beforeInsertBatch, $afterInsertBatch, $beforeUpdateBatch and $afterUpdateBatch can be used since v4.3.0.

Defining Callbacks

You specify the callbacks by first creating a new class method in your model to use.

This class method will always receive a $data array as its only parameter.

The exact contents of the $data array will vary between events, but will always contain a key named data that contains the primary data passed to the original method. In the case of the insert*() or update*() methods, that will be the key/value pairs that are being inserted into the database. The main $data array will also contain the other values passed to the method, and be detailed in Event Parameters.

The callback method must return the original $data array so other callbacks have the full information.

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected function hashPassword(array $data)
    {
        if (! isset($data['data']['password'])) {
            return $data;
        }

        $data['data']['password_hash'] = password_hash($data['data']['password'], PASSWORD_DEFAULT);
        unset($data['data']['password']);

        return $data;
    }
}

Specifying Callbacks To Run

You specify when to run the callbacks by adding the method name to the appropriate class property ($beforeInsert, $afterUpdate, etc). Multiple callbacks can be added to a single event and they will be processed one after the other. You can use the same callback in multiple events:

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $beforeInsert = ['hashPassword'];
    protected $beforeUpdate = ['hashPassword'];

    // ...
}

Additionally, each model may allow (default) or deny callbacks class-wide by setting its $allowCallbacks property:

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $allowCallbacks = false;

    // ...
}

You may also change this setting temporarily for a single model call using the allowCallbacks() method:

<?php

$model->allowCallbacks(false)->find(1); // No callbacks triggered
$model->find(1); // Callbacks subject to original property value

Event Parameters

Since the exact data passed to each callback varies a bit, here are the details on what is in the $data parameter passed to each event:

Event	$data contents
beforeInsert	data = the key/value pairs that are being inserted. If an object or Entity class is passed to the insert() method, it is first converted to an array.
afterInsert	id = the primary key of the new row, or 0 on failure. data = the key/value pairs being inserted. result = the results of the insert() method used through the Query Builder.
beforeUpdate	id = the array of primary keys of the rows being passed to the update() method. data = the key/value pairs that are being updated. If an object or Entity class is passed to the update() method, it is first converted to an array.
afterUpdate	id = the array of primary keys of the rows being passed to the update() method. data = the key/value pairs being updated. result = the results of the update() method used through the Query Builder.
beforeFind	The name of the calling method, whether a singleton was requested, and these additional fields:
first()	No additional fields
find()	id = the primary key of the row being searched for.
findAll()	limit = the number of rows to find. offset = the number of rows to skip during the search.
afterFind	Same as beforeFind but including the resulting row(s) of data, or null if no result found.
beforeDelete	id = primary key of row being passed to the delete() method. purge = boolean whether soft-delete rows should be hard deleted.
afterDelete	id = primary key of row being passed to the delete() method. purge = boolean whether soft-delete rows should be hard deleted. result = the result of the delete() call on the Query Builder. data = unused.
beforeInsertBatch	data = associative array of values that are being inserted. If an object or Entity class is passed to the insertBatch() method, it is first converted to an array.
afterInsertBatch	data = the associative array of values being inserted. result = the results of the insertbatch() method used through the Query Builder.
beforeUpdateBatch	data = associative array of values that are being updated. If an object or Entity class is passed to the updateBatch() method, it is first converted to an array.
afterUpdateBatch	data = the key/value pairs being updated. result = the results of the updateBatch() method used through the Query Builder.

Modifying Find* Data

The beforeFind and afterFind methods can both return a modified set of data to override the normal response from the model. For afterFind any changes made to data in the return array will automatically be passed back to the calling context. In order for beforeFind to intercept the find workflow it must also return an additional boolean, returnData:

<?php

namespace App\Models;

use CodeIgniter\Model;

class MyModel extends Model
{
    // ...

    protected $beforeFind = ['checkCache'];

    // ...

    protected function checkCache(array $data)
    {
        // Check if the requested item is already in our cache
        if (isset($data['id']) && $item = $this->getCachedItem($data['id'])) {
            $data['data']       = $item;
            $data['returnData'] = true;

            return $data;
        }

        // ...
    }
}

Manual Model Creation

You do not need to extend any special class to create a model for your application. All you need is to get an instance of the database connection and you’re good to go. This allows you to bypass the features CodeIgniter’s Model gives you out of the box, and create a fully custom experience.

<?php

namespace App\Models;

use CodeIgniter\Database\ConnectionInterface;

class UserModel
{
    protected $db;

    public function __construct(ConnectionInterface $db)
    {
        $this->db = $db;
    }
}