Can I use a belongsTo method with name 'asset'? - laravel

Question

I have a model "SalesContract" which has a "belongsTo" relationship with a class called "Asset". However, it does not work (I cannot set or get).
Could it be an issue with the "asset()" helper method?
If I change the name of my method to something like "related_asset()", then it works.
This does NOT work:
public function asset()
{
return $this->belongsTo(Asset::class);
}
This DOES work:
public function related_asset()
{
return $this->belongsTo(Asset::class);
}
Full model:
class SalesContract extends Model
{
use SoftDeletes;
use Commentable;
const icon_class = 'far fa-file-signature';
const default_buyer_fee = 100;
const default_carproof_fee = 36.45;
protected $fillable = [
'number', 'asset_id', 'seller_id', 'buyer_id', 'buyer_representative', 'sale_date', 'sale_price',
'apply_sales_taxes_to_sale_price', 'buyer_fee', 'carproof_fee', 'deposit'
];
protected $casts = [
'sale_date' => 'datetime',
'sale_price' => 'float',
'carproof_fee' => 'float',
'buyer_fee' => 'float',
'deposit' => 'float',
'created_at' => 'datetime',
'updated_at' => 'datetime',
'deleted_at' => 'datetime'
];
protected $appends = [
'subtotal', 'taxable_amount', 'sales_taxes', 'total', 'balance'
];
protected static function boot()
{
parent::boot();
static::addGlobalScope('order', function (Builder $builder) {
$builder->orderBy('created_at', 'desc');
});
static::saving(function($table) {
if (empty($table->id)) {
if ($current_user = Auth::user()) {
$table->created_by_user_id = $current_user->id;
}
}
});
}
public function __construct(array $attributes = [])
{
if (empty($this->sale_date)) {
$this->sale_date = Carbon::today()->format('Y-m-d');
}
if (empty($this->id)) {
if (empty($this->number)) {
if ($asset = $this->asset) {
$this->number = $asset->external_file_number ?? $asset->internal_file_number;
}
}
$this->buyer_fee = $this->buyer_fee ?? self::default_buyer_fee;
$this->carproof_fee = $this->carproof_fee ?? self::default_carproof_fee;
$this->apply_sales_taxes_to_sale_price = $this->apply_sales_taxes_to_sale_price ?? 1;
}
parent::__construct($attributes);
}
public function __toString()
{
return __('sales_contracts.item_label', ['number' => $this->number ?? $this->id]);
}
public function scopeFilter($query, $filters)
{
$filters = is_array($filters) ? array_filter($filters) : [];
return $query->where($filters);
}
public function asset()
{
return $this->belongsTo(Asset::class);
}
public function seller()
{
return $this->belongsTo(Contact::class);
}
public function buyer()
{
return $this->belongsTo(Contact::class);
}
public function created_by_user()
{
return $this->belongsTo(User::class);
}
public function getSubtotalAttribute()
{
return $this->sale_price + $this->carproof_fee + $this->buyer_fee;
}
public function getTaxableAmountAttribute()
{
if ($this->apply_sales_taxes_to_sale_price) {
return $this->subtotal;
} else {
return $this->subtotal - $this->sale_price;
}
}
public function getSalesTaxesAttribute()
{
$sales_taxes = [];
if ($seller = $this->seller) {
foreach ($seller->sales_tax_numbers as $tax_number) {
if ($tax_number->use) {
if ($sales_tax = $tax_number->sales_tax) {
$sales_taxes[] = [
'sales_tax' => $sales_tax,
'name' => $sales_tax->name,
'rate' => $sales_tax->rate,
'label' => $sales_tax->label,
'number' => $tax_number->number,
'amount' => round($this->taxable_amount * $sales_tax->rate, 2)
];
}
}
}
}
return $sales_taxes;
}
public function getSalesTaxesTotalAttribute()
{
$total = 0;
foreach ($this->sales_taxes as $sales_tax) {
$total += $sales_tax['amount'];
}
return $total;
}
public function getTotalAttribute()
{
return $this->subtotal + $this->sales_taxes_total;
}
public function getBalanceAttribute()
{
return $this->total - $this->deposit;
}
}
From controller:
$sales_contract = new SalesContract;
if ($request->has('sales_contract')) {
$sales_contract->fill($request->input('sales_contract'));
}
Result of dd($request->input()):
array:1 [▼
"sales_contract" => array:1 [▼
"asset_id" => "11754"
]
]
(Yes, Asset with ID 11754 does exist.)

Answer 1

by default Name of relation is depended on 'foreign_key'
if you want to set different name of relation than foreign key just provide foreign key and other_key along with relation declaration
public function asset()
{
return $this->belongsTo(Asset::class,related_asset,id);
}

Answer 2

Problem solved.
I had to remove the following code from my __construct() method as it was breaking the relationship somehow:
if (empty($this->number)) {
if ($asset = $this->asset) {
$this->number = $asset->external_file_number ?? $asset->internal_file_number;
}
}