ActiveRow: Trying to get property of non-object & Selection: Invalid argument supplied for foreach()

[hranicka]

In some cases (delete of cache files, access to one page and then access to another page) Nette\Database\Table\ActiveRow::accessColumn generates Notice.

I can't write test case because bug is unpredictable.

My temporary solution is edit Nette\Database\Table\Selection::offsetGet, but it's only a hack IMHO (and is applied only to ::offsetGet).

public function offsetGet($key)
{
    $this->execute();

    // solves strange cache bug
    $rows = ($this->rows) ? : $this->data;

    return $rows[$key];
}

Another hack is edit Nette\Database\Table\ActiveRow::accessColumn like this:

protected function accessColumn($key, $selectColumn = TRUE)
{
    $this->table->accessColumn($key, $selectColumn);
    if ($this->table->getDataRefreshed() && !$this->dataRefreshed) {
        $row = ($this->table[$this->getSignature()]) ? : $this->table->get($this->getSignature());
        $this->data = $row->data;
        $this->dataRefreshed = TRUE;
    }
}

---

Related topic in forum:

• http://forum.nette.org/cs/19508-trying-to-get-property-of-non-object

---

I can't reproduce issue artifically so I can't write tests and create full pull-request at the moment :(
Codes above are only my "hacks" until we found right cause of the issue.

[hrach]

@hranicka Sadly, I really need the reproducible usecase. On forum you have written that it appears, if .... -> so is it reproducible on your project, but you can it reproduce on sandbox? Would you accept sending privately your project with the bug to my email?

[nechutny]

I have same problem. After cleaning temp dir first page render is ok, refresh throw this error and next refresh fix it to next cleaning temp dir.

Error is throwing code:

{foreach $fb_galleries as $gal}
    <div class="album">
        <a href="{plink Gallery:facebook $gal->url}" title="{$gal->name}">
            {var $photo = $gal->related('facebook_photo')->order('id')->limit(1)->fetch()}

            {if is_object($photo)}
                {var $url = 'FB-'.$photo->url}
            {else}
                {var $url = "none"}
            {/if}
            <img src="{plink Gallery:image $url,208,150,'crop'}" alt="{$gal->name}">
            <h2>
                <strong>{$gal->name}</strong><br>{$gal->created|date:'d. m. Y'} | Fotek: {$gal->related('facebook_photo')->count()}
            </h2>
        </a>
    </div>
{/foreach}

and error is throwing {var $url = 'FB-'.$photo->url} even if it pass through if(is_object())

[mishak87]

I think I have encountered something similar while back. I found out that in cache was incomplete row from partial select and on full select that cache was used leaving some properties empty.

[dg]

@hrach is finer caching granularity correct fix for this issue? Partial row should re-execute query and not to throw error.

[hrach]

@dg yes, definitelly not, however, fi they weren't able to reproduci it untill now, I thing there will never be.

[hranicka]

@hrach 408925f really fixes the problem. However if I'll try reproduce the bug on nette/sandbox v2.2.2, will be it still useful for you (you've written tests for it in 408925f )?

Because our project is huge monster for this purpose, so I can try reproduce the bug on clean sandbox...

[hrach]

@hranicka It would be awesome If you be able to reproduce it. No, it's not the test for that...it's just rewritten old one.

[hranicka]

@hrach I'm trying evoke the bug in simple situation in nette/sandbox v2.2.2 but there it works fine. It's really strange :( I'll try it again later with more comlex DB structure. Until I can't help more, because I can't reproduce the bug on simple project when I need... it maybe appears only in some situations on larger projects :( During week I'll try create a buggy environment in nette/sandbox, but I'm sceptic that I succeed. But hope...

[hrach]

@hranicka thanks! :)

[hranicka]

@hrach So I've tried envoke the bug on nette/sandbox v2.2.2 with custom DB structures but everything worked fine. Sorry, I can't reproduce test case for the bug when I need :(

[hrach]

@hranicka that's the sad story... the system is quite complex and I believe I have fiexed almost everything what I could fixed :)