如何在laravel中的三个model的pivot中部署关系？

Question

I'm developing a role and permissions based on laravel framework.

I have 3 models:

Weblog
User
Permissions

This is pivot table

user_id , weblog_id , permission_id

Now, a user can have a weblog with permission id 1,2 and another weblog with permission 1,2,3,4

How can I deploy relationships? and how can I check user permissions when managing a weblog. (middleware and...)

Answer 1

With the fact that Permission are specific to Weblog

Say the pivot table is called permission_user_weblog

class User extends Model
{
    public function weblogs()
    {
        return $this->belongsToMany(Weblog::class, 'permission_user_weblog');
    }

    public function permissionsFor(int $weblogId)
    {
        $permissionIds = null;

        $this->weblogs()
            ->where('id', $weblogId)
            ->with('permissions')
            ->get()
            ->each(function($weblog) use(&$permissionIds) {
                $permissionIds = $weblog->permissions->pluck('id');             
            });

        return $permissionIds;
    }
}


class Weblog extends Model
{
    public function users()
    {
        return $this->belongsToMany(User::class, 'permission_user_weblog');
    }

    public function permissions()
    {
        return $this->belongsToMany(Permission::class, 'permission_user_weblog');
    }
}


class Permission extends Model
{
    public function weblogs()
    {
        return $this->belongsToMany(Weblog::class, 'permission_user_weblog');
    }
}

Then you can check anywhere for whether logged in user has specific permission for a specific weblog

public function update(Request $request, $weblogId)
{
    $user = auth()->user();
    $permissions = $user->permissionsFor($weblogId);

    //Check whether the logged in user has permission identified by id 1 or 4 for weblog
    $can = !! $permissions->intersect([1,4])->count();

    //Do rest of processing
}

Answer 2

your Weblog,User,Permission has ManyToMany Relation, its a kind of odd but if you want to have this kind of relation its not a problem.

just consider each pair a ManyToMany . and every one of those can have a hasMany to Pivot (i named it Access) too (based on your needs).

User model:

class User extends Model{

/**
      * retrive weblogs
      *
      * @return BelongsToMany weblogs
      */
     public function weblogs()
     {
         return $this->belongsToMany(App\WebLog::class,'accesses_table')
                        ->withPivot("permission_id")
                        ->using(App\Access::class);
     }

/**
      * retrive permissions
      *
      * @return BelongsToMany permissions
      */
     public function permissions()
     {
         return $this->belongsToMany(App\Permission::class,'accesses_table')
                        ->withPivot("weblog_id")
                        ->using(App\Access::class);
     }

/**
      * retrive access
      *
      * @return hasMany [description]
      */
     public function accesses()
     {
         return $this->hasMany(App\Access::class, "user_id");
     }
}

Weblog model:

class Weblog extends Model{

/**
      * retrive users
      *
      * @return BelongsToMany users
      */
     public function users()
     {
         return $this->belongsToMany(App\User::class,'accesses_table')
                        ->withPivot("permission_id")
                        ->using(App\Access::class);
     }

/**
      * retrive permissions
      *
      * @return BelongsToMany permissions
      */
     public function permissions()
     {
         return $this->belongsToMany(App\Permission::class,'accesses_table')
                        ->withPivot("user_id")
                        ->using(App\Access::class);
     }

/**
      * retrive access
      *
      * @return hasMany [description]
      */
     public function accesses()
     {
         return $this->hasMany(App\Access::class, "weblog_id");
     }
}

Permission model:

class Permission extends Model{

/**
      * retrieve users
      *
      * @return BelongsToMany users
      */
     public function users()
     {
         return $this->belongsToMany(App\User::class,'accesses_table')
                        ->withPivot("weblog_id")
                        ->using(App\Access::class);
     }

/**
      * retrieve weblogs
      *
      * @return BelongsToMany weblogs
      */
     public function weblogs()
     {
         return $this->belongsToMany(App\Weblog::class,'accesses_table')
                        ->withPivot("user_id")
                        ->using(App\Access::class);
     }

/**
      * retrive access
      *
      * @return hasMany [description]
      */
     public function accesses()
     {
         return $this->hasMany(App\Access::class, "permission_id");
     }
}

and you can have a model for your pivot , which i named it Access :

Illuminate\Database\Eloquent\Relations\Pivot;

class Access extends Pivot
{

    public $incrementing = true;

public function user()
    {
        return $this->belongsTo(App\User::class);
    }

    public function weblog()
    {
        return $this->belongsTo(App\Weblog::class);
    }

    public function permission()
    {
        return $this->belongsTo(App\Permission::class);
    }

}