Route Custom binding Laravel overwrite

Because we work with a middleware API, we fixed a custom route binder that looks against our middleware API instead of the general database by Eloquent.

Problem is now. When there is more then 1 parameter it only retrieve the last binding. It overrides the previous call.

Binder

public function syncBinding(): void
{
    if (array_key_exists(mb_strtolower(class_basename($this)), self::$bindable)) {
        return;
    }

    $routeBinding = Request::getRouteResolver()->call($this);
    $parameters = $routeBinding->parameters();
    $bindingFields = $routeBinding->bindingFields();

    $bind = mb_strtolower(class_basename($this));

    if (array_key_exists($bind, self::$bindable) || ! array_key_exists($bind, $parameters)) {
        return;
    }

    $column = null;
    if (array_key_exists($bind, $bindingFields)) {
        $column = $bindingFields[$bind];
    }

    self::$bindable[$bind] = true;
    $this->items = $this->resolveBinding($this, $parameters[$bind], $column);
}

The items property is holding the binding, but it will be overridden once there are more then 1 parameters.

How can I fix this?

Based on your code, the issue occurs because the $this->items property is overwritten each time the syncBinding function is called. If there are multiple parameters, each call overwrites the previous result. Therefore, the property only retains the result from the last parameter processed.

One solution could be to change $this->items from holding a single item to holding an array of items. Each time syncBinding is called, instead of overwriting the current value of $this->items, you would push the new value onto the array. You can try following solution. Maybe some errors can occur and you can debug and fix it. But general idea should be like this:

public function syncBinding(): void
{
    if (array_key_exists(mb_strtolower(class_basename($this)), self::$bindable)) {
        return;
    }

    $routeBinding = Request::getRouteResolver()->call($this);
    $parameters = $routeBinding->parameters();
    $bindingFields = $routeBinding->bindingFields();

    $bind = mb_strtolower(class_basename($this));

    if (array_key_exists($bind, self::$bindable) || ! array_key_exists($bind, $parameters)) {
        return;
    }

    $column = null;

    if (array_key_exists($bind, $bindingFields)) {
        $column = $bindingFields[$bind];
    }

    self::$bindable[$bind] = true;

    if (!is_array($this->items)) {
        $this->items = [];
    }

    array_push($this->items, $this->resolveBinding($this, $parameters[$bind], $column));
}

Please note that with these changes, $this->items will now be an array containing all the resolved bindings for each parameter. So, you may need to adjust the rest of your code that makes use of $this->items to account for this change.