Feature Request: map relation filter functions

[lkreher]

When defining a filter on a relation it would be great to also define which filter function to use. Currently the filter function on the related model has to be the same as the filter attribute on the original model. For example: I have a user model with a name filter. I have an issue model that has an author and an assignee. Currently I would have to write

class UserFilter extends ModelFilter
{
    public function name(string $name)
    {
        foreach (explode(' ', $name) as $part) {
            $this->where(function ($query) use ($part) {
                $query->where('first_name', 'LIKE', '%' . $part . '%')
                    ->orWhere('last_name', 'LIKE', '%' . $part . '%');
            });
        }

        return $this;
    }

    public function authorName(string $name)
    {
        return $this->name($name);
    }

    public function assigneeName(string $name)
    {
        return $this->name($name);
    }
}

class IssueFilter extends ModelFilter
{
    public $relations = ['author' => ['author_name'], 'assignee' => ['assignee_name']];
}

It would be great If I could just do:

class IssueFilter extends ModelFilter
{
    public $relations = ['author' => ['author_name' => 'name'], 'assignee' => ['assignee_name' => 'name']];
}

So when I filter by author_name on the issue model, I filter by the name-attribute on the author relation.

[Tucker-Eric]

I like it! Looks like it would be easy to implement without breaking backwards comparability. I'm open to a pr on this.

[Tucker-Eric]

Added in 2.2.0