JSON Column Guard

This package allows validation and custom casts for JSON columns.

Have you ever tried to use a json column, and:

1. Validating schema of the column was difficult or messy
2. Querying the column was onerous
3. Casting types when saving models wasn't fun

Well now you can rest easy!

Example

You want to save user preferences. It's highly dynamic data, so you throw it into a json column:

Database Table	Database Column	Desired Schema
users	preferences	[ { "name": "Favorite Band", "value": "Slenderbodies", "date_created": "2019-09-15", "date_updated": "2020-01-01" } ]

Here are problems:

1. Can you enforce each key is valid?
2. Can you enforce the two dates are valid dates?
3. What about always ensuring the column is an array, regardless if a preference exists or not?

We can.

Step 1: Create The Validator Class

Let's use Laravel's own Validator syntax to describe what we want.

<?php
namespace App\Models\User;

use Zschuessler\ModelJsonAttributeGuard\JsonAttributeGuard;

class PreferencesJsonColumn extends JsonAttributeGuard
{

    public function schema() : array
    {
        return [
            // Use wildcard syntax to apply rules to all children
            '*.name'           => 'required',
            '*.value'          => 'required|min:3',
            '*.date_created'   => 'present|nullable|date',
            '*.date_updated'   => 'present|nullable|date',
        ];
    }
}

Under the hood Laravel's Validators are used: you can use any rule you want. Go nuts.

Step 2: Add a trait and cast to your Model

Let's tell Laravel we want our model to do a custom cast:

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use App\Models\User\PreferencesJsonColumn;
use Zschuessler\ModelJsonAttributeGuard\Traits\HasJsonAttributeGuards;

class User extends Model
{
    use HasJsonAttributeGuards;

    public $casts = [
        'preferences' => PreferencesJsonColumn::class
    ];

Step 3: Success

This code will work wonderfully:

$user->preferences = [
    [
        'name' => 'Favorite Band',
        'value' => 'Slenderbodies',
        'date_created' => '2019-09-15',
        'date_updated' => '2020-01-01'
    ]
];
$user->save();

Great! But the code below will throw a JsonAttributeValidationFailedException exception - oh no! Your model won't be saved.

$user->preferences = [
    'name' => null,
    'value' => null,
    'date_created' => null,
    'date_updated' => null,
];
$user->save();

This was a simple example. The possibilities are endless!