Laravel Eloquent setting a default value for a model relation?

Question

I have two models: ``` class Product extends Eloquent { ... public function defaultPhoto() { return $this->belongsTo('Photo'); } public function photos() { return $this->hasMany('Photo'); } } class Photo extends Eloquent { ... public function getThumbAttribute() { return 'products/' . $this->uri . '/thumb.jpg'; } public function getFullAttribute() { return 'products/' . $this->uri . '/full.jpg'; } ... } ``` This works fine, I can call `$product->defaultPhoto->thumb` and `$product->defaultPhoto->full` and get the path to the related image, and get all photos using `$product->photos` and looping through the values. The problem arises when the product does not have a photo, I can't seem to figure out a way to set a default value for such a scenario. I have tried doing things such as ``` public function photos() { $photos = $this->hasMany('Photo'); if ($photos->count() === 0) { $p = new Photo; $p->url = 'default'; $photos->add($p); } return $photos; } ``` I have also creating a completely…

Accepted Answer

You could create an accessor on the Product model that did the check for you. Works the same if you just wanted to define it as a method, also (good for if you want to abstract some of the Eloquent calls, use an interface for your Product in case you change it later, etc.)

```
/**
 * Create a custom thumbnail "column" accessor to retrieve this product's
 * photo, or a default if it does not have one.
 * 
 * @return string
 */
public function getThumbnailAttribute()
{
    $default = $this->defaultPhoto;

return ( ! is_null($default))
        ? $default->thumb
        : '/products/default/thumb.jpg';
}
```

You might also want to look into Presenters. A bit overkill for some situations, but incredibly handy to have (and abstract things like this away from your models).

Laravel Eloquent setting a default value for a model relation?

Solution

Problem