Models: Accessors & Mutators

Introduction

Accessors and mutators allow you to modify attribute values when you retrieve or set them on model instances. If you'd ever used Laravel accessors or mutators, you'll feel right at home.

Accessors & Mutators

Defining An Accessor

For an example, lets say we are working with Active Directory and we want to encode the thumbnailPhoto attribute whenever we retrieve it from our User model.

To define an accessor for this attribute, we define a method named getThumbnailphotoAttribute():

<?php

use LdapRecord\Models\Model;

class User extends Model
{
    public function getThumbnailphotoAttribute($value)
    {
        // Due to LDAP's multi-valued nature, all values will be
        // contained inside of an array. We will attempt to
        // retrieve the first one, or supply a default.
        $data = $value[0] ?? file_get_contents('images/default_photo.jpg');

        $image = base64_encode($data);

        $mime = 'image/jpeg';

        if (function_exists('finfo_open')) {
            $finfo = finfo_open();

            $mime = finfo_buffer($finfo, $data, FILEINFO_MIME_TYPE);

            return "data:$mime;base64,$image";
        }

        return "data:$mime;base64,$image";
    }
}

As you can see from the above, the attribute name we want to create an accessor for, must be between get and Attribute.

The casing of get and Attribute are very important. This casing difference is how LdapRecord detects accessor and mutator methods.

If your attribute contains a hyphen, use must use alternate casing to indicate this. For example, lets create an accessor for the apple-user-homeurl attribute:

<?php

use LdapRecord\Models\Model;

class User extends Model
{
    public function getAppleUserHomeurlAttribute($value)
    {
        // Do something with its value.
        return $value;
    }
}

As you can see, alternate casing indicates to LdapRecord that the attribute we are looking for contains hyphens.

Defining A Mutator

A mutator does the opposite of an accessor. A mutator is a function you define that accepts the value of the attribute you are setting so you can transform it before it is set onto the model.

To define a mutator, we use the above accessor syntax with set instead of get.

For example, let's define a unicodepwd mutator that automatically encodes a password by setting the attribute:

<?php

use LdapRecord\Utilities;
use LdapRecord\Models\Model;

class User extends Model
{
    public function setUnicodepwdAttribute($password)
    {
        $this->attributes['unicodepwd'] = [Utilities::encodePassword($password)];
    }
}

Now once we set the attribute, it will automatically encode the password we are setting on the User model:

$user = new User();

$user->unicodepwd = 'secret';

Date Mutators

By default, LdapRecord will convert the attributes createtimestamp and modifytimestamp to instances of Carbon.

If you extend from ActiveDirectory models, the attributes whenchanged and whencreated will be converted instead.

When you define an attribute as a date, you can set its value to an instance of DateTime / Carbon instance, a UNIX timestamp, or a date string (Y-m-d). Upon saving your model, these will be converted properly to be stored in your directory.

To define a mutator for an attribute that contains a timestamp, we must set the $dates property on the model. However, since LDAP directories have different timestamp formats for some attributes, we must tell LdapRecord what kind of format to use for proper conversion.

For example, let's define a date mutator for the accountexpires attribute that exists on Active Directory. To do so, we must set the $dates property to a key / value pair, where the key is the attribute that contains the timestamp and the value is the type of LDAP format to convert to and from:

<?php

use LdapRecord\Models\Model;

class User extends Model
{
    protected $dates = [
        'accountexpires' => 'windows-int',
    ];
}

Now lets have our user's account expire at the same time tomorrow:

$user = User::find('cn=John Doe,dc=local,dc=com');

$user->accountexpires = new \DateTime('+1 day');

$user->save();

Once we've saved the model, the attribute will now automatically be converted to a Carbon instance so you can use any of Carbon's methods on the attribute:

$user = User::find('cn=John Doe,dc=local,dc=com');

if ($user->accountexpires->isPast()) {
    // The user account is expired.
}

Available Types

Currently, there are 3 built-in date mutator types. They are:

• ldap
• windows
• windows-int

LDAP Type

The ldap type is the most common format for LDAP timestamps - outside of Active Directory. This format converts LDAP timestamps in the format of YYYYMMDDHHMMSST. T is the time zone which is usually 'Z' (Zulu Time Zone = UTC/GMT).

Windows Type

The windows type is similar to the ldap type, however it differs slightly so it requires its own conversion type. Its timestamp is in the format of YYYYMMDDHHMMSS.0T. T is the time zone which is usually 'Z' (Zulu Time Zone = UTC/GMT).

Windows Integer Type

The windows-int type handles the 18-digit Active Directory timestamp format, also named 'Windows NT time format', 'Win32 FILETIME or SYSTEMTIME' or NTFS file time. An example of this would be the accountexpires attribute that exists on users:

132131246410000000

Which equals:

Monday, September 16, 2019 4:24:01 PM

Attribute Casting

Similarly with Laravel's Eloquent, the $casts property on your model provides a convenient method of converting attributes to common data types. The $casts property should be an array where the key is the name of the attribute being cast and the value is the type you wish to cast the column to.

The supported cast types are:

• integer
• real
• float
• double
• decimal:<digits>
• string
• boolean
• object
• array
• collection
• datetime:<ldap/windows/windows-int>

To demonstrate attribute casting, let's cast the msExchHideFromAddressList Active Directory attribute, which determines whether a user account is shown in the Global Address List in Outlook.

This attribute is stored as a string in Active Directory, with the value TRUE or FALSE.

namespace App\Models\Ldap;

use LdapRecord\Models\ActiveDirectory\User as BaseUser;

class User extends BaseUser
{
    protected $casts = [
        'msExchHideFromAddressList' => 'boolean',
    ];
}

Then, we can utilize it when we retrieve users from our directory:

$user = User::find('cn=John Doe,dc=local,dc=com');

if ($user->msExchHideFromAddressList) {
    // This user is being hidden from the Global Address list.
}

Appending Accessors

Ported directly from Laravel's Eloquent, the $appends array property can be set directly on the model class to add an accessor's value to the models array form.

Important: LDAP attributes cannot contain underscores (_). Therefore, all accessors that are PascalCased must be defined in their hyphenated format, and will appear in their hyphenated format in the model's array form.

namespace App\Models\Ldap;

use LdapRecord\Models\ActiveDirectory\User as BaseUser;

class User extends BaseUser
{
    protected $appends = ['full-name'];

    public function getFullNameAttribute()
    {
        return 'John Doe';
    }
}

$user = User::find('cn=john,dc=local,dc=com');

// Displays: "John Doe"
echo $user->full_name;

// Displays: "{"full-name":["John Doe"]}"
echo json_encode($user);