Simple Multitenancy Setup

The last thing before we start working on the Flutter mobile application is that we want multi-tenancy for our Users. In our case, we want the easiest multi-tenancy option - user_id filtering. So, let's implement the following:

• Global scopes for Category and Transaction models
• Refactoring of Category and Transaction controllers to create records for our user

These are small changes, but they will make our application multi-tenant. Let's start with the global scope.

Global Scopes for Category and Transaction Models

Let's start with a quick overview of our logic:

• On our Models, we have a user_id column that relates to the User
• We want to apply a global scope to our Models to filter records by user_id
• This should be done automatically when we query our Models

Let's implement this in our Category model:

app/Models/Category.php

use Illuminate\Database\Eloquent\Builder;
 
// ...
 
protected static function booted(): void
{
    if (auth()->check()) {
        static::addGlobalScope('by_user', function (Builder $builder) {
            $builder->where('user_id', auth()->id());
        });
    }
}

And we can do exactly the same to our Transaction model:

app/Models/Transaction.php

use Illuminate\Database\Eloquent\Builder;
 
// ...
 
protected static function booted(): void
{
    if (auth()->check()) {
        static::addGlobalScope('by_user', function (Builder $builder) {
            $builder->where('user_id', auth()->id());
        });
    }
}

That's it! Now, if we use our API token and query Categories - we can't see any since we don't have any Categories created for our User:

Modifying Record Creation

Let's fix the problem of our Users not having any Categories or Transactions. We will modify our Category and Transaction controllers to create records for our User:

app/Http/Controllers/CategoryController.php

// ...
 
public function store(StoreCategoryRequest $request)
{
    return new CategoryResource(Category::create($request->validated()));
    $category = auth()->user()->categories()->create($request->validated());
 
    return new CategoryResource($category);
}

We simply switch from Category::create to auth()->user()->categories()->create(). But for this to work, we have to add the relationship to our User model:

app/Models/User.php

use Illuminate\Database\Eloquent\Relations\HasMany;
 
// ...
 
public function categories(): HasMany
{
    return $this->hasMany(Category::class);
}

And we can do the same for our Transaction controller:

app/Http/Controllers/TransactionController.php

public function store(StoreTransactionRequest $request)
{
    return new TransactionResource(Transaction::create($request->validated()));
    $transaction = auth()->user()->transactions()->create($request->validated());
 
    return new TransactionResource($transaction);
}

And once again, we have to add the relationship to our User model:

app/Models/User.php

// ...
 
public function categories(): HasMany
{
    return $this->hasMany(Category::class);
}
 
public function transactions(): HasMany
{
    return $this->hasMany(Transaction::class);
}

Now, let's try to create a Category using Postman:

And, of course, if we try to load all categories, we see only the one we created:

That's it. We have implemented a simple multi-tenancy for our Users.

In the next lesson, we will start working on the Flutter application. We will start with a basic setup and get to know the Flutter environment.

Check out the GitHub Commit