Exploring Laravel's recursive relationships feature and understanding the concept of returning $this

Question

Exploring Laravel's recursive relationships feature and understanding the concept of returning $this

I am working on a navigation bar that contains industries with potentially unknown levels, including child industries. My goal is to create a recursive relationship to retrieve the top industry and display it as the main Category. The code snippet I attempted looks like this:

public function category()
{
    if($this->parent_id == 0){
        return $this;
    } else {
        $this->parent_industry->category();
    }
}

However, I encountered the following error message: LogicException: Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation

Can anyone suggest a solution for creating a recursive relationship and returning $this?

php laravel recursion relationship

Answer 1

Answer №1

Here are some recommended relationships:

public function children()
{
    return $this->hasMany('App\MenuItem', 'parent_id');
}

public function parent()
{
    return $this->belongsTo('App\MenuItem', 'parent_id');
}

public function getRoot()
{
    $cur = $this;
    while ($cur->parent) {
        $cur = $cur->parent;
    }
    return $cur;
}

Answer 2

Here are some recommended relationships:

public function children()
{
    return $this->hasMany('App\MenuItem', 'parent_id');
}

public function parent()
{
    return $this->belongsTo('App\MenuItem', 'parent_id');
}

public function getRoot()
{
    $cur = $this;
    while ($cur->parent) {
        $cur = $cur->parent;
    }
    return $cur;
}

Answer 3

Answer №2

Hey there! An alternative approach to achieve this is by implementing recursion rather than using a while loop.

public function children()
{
   return $this->hasMany('App\ItemCategory', 'parent_id');
}

public function parent()
{
   return $this->belongsTo('App\ItemCategory', 'parent_id');
}

public function root()
{
    if ($this->parent)
        return $this->parent->root();

    return $this;
}

By utilizing recursion, the process becomes much more straightforward.

I hope this solution proves helpful for you.

Answer 4

Hey there! An alternative approach to achieve this is by implementing recursion rather than using a while loop.

public function children()
{
   return $this->hasMany('App\ItemCategory', 'parent_id');
}

public function parent()
{
   return $this->belongsTo('App\ItemCategory', 'parent_id');
}

public function root()
{
    if ($this->parent)
        return $this->parent->root();

    return $this;
}

By utilizing recursion, the process becomes much more straightforward.

I hope this solution proves helpful for you.

Exploring Laravel's recursive relationships feature and understanding the concept of returning $this

Answer №1

Answer №2

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