Relationships manyToOne NULL

[atlasphp]

Relationships manyToOne NULL

[ElGigi]

The same problem for oneToOne relationship.

A track for resolution?

class OneToOne extends DeletableRelationship
{
    protected function stitchIntoRecord(
        Record $nativeRecord,
        array $foreignRecords
    ) : void {
        $nativeRecord->{$this->name} = false;
        if ($this->onDelete === static::SET_NULL) {
            $nativeRecord->{$this->name} = null;
        }

        foreach ($foreignRecords as $foreignRecord) {
            if ($this->recordsMatch($nativeRecord, $foreignRecord)) {
                $nativeRecord->{$this->name} = $foreignRecord;
            }
        }
    }

    // ...
}

So if reference column can be null, the value must not be false but null?

[pmjones]

/me ponders

Can you tell me a little about the domain object that is being built from the record?

[ElGigi]

Yes.

For example:

class Author
{
    // ...

    public function __construct(?int $author_id, ?string $name)
    {
        $this->author_id = $author_id;
        // ...
    }
}

class Thread
{
    public function __construct(?int $article_id, ?string $title, ?string $content, ?Author $author)
    {
        $this->article_id = $article_id;
        // ...
    }
}

And the relationships in DataSource:

class AuthorRelationships extends MapperRelationships
{
    protected function define()
    {
        $this->oneToMany('threads',
                         Thread::CLASS,
                         [
                             'author_id' => 'author_id',
                         ]);
    }
}

class ThreadRelationships extends MapperRelationships
{
    protected function define()
    {
        $this->manyToOne('author',
                        Author::CLASS,
                        [
                            'author_id' => 'author_id',
                        ])
             ->onDeleteSetNull();
    }
}

[pmjones]

And the problem is that sometimes, when you fetch a ThreadRecord from the data source with('author'), the author field is false because there is no related author row?

[ElGigi]

Yes is that.
If no author, for anonymous thread (for example), the field is false instead null.

[pmjones]

All right, I think I understand now.

Some background: the false is there to indicate that you tried to fetch a relationship, but there was nothing related (as vs null which means you never tried to fetch the relationship in the first place).

The most expedient solution I can think of is to modify Atlas Transit to accept both "false" and "null" to mean "null" when the target domain property is an object. Would that work for you here?

[ElGigi]

Yes of course, that will works for me if it's implemented in Transit.

[pmjones]

@ElGigi please examine atlasphp/Atlas.Transit#7 and see if it works for you!