Allow DCA filter definitions without placeholder values

[fritzmg]

In a project of ours we dynamically injected a DCA filter into

$GLOBALS['TL_DCA']['tl_foo']['list']['sorting']['filter']

via an onload_callback. However, in our case we wanted to add a query like this:

foo NOT IN (…)

Initially we added the filter like this:

$GLOBALS['TL_DCA']['tl_foo']['list']['sorting']['filter'][] = ['foo NOT IN ('.implode(',', $ids).')'];

However, since Contao assumes that these filters are always a placeholder/value pair, the placeholders and values will mismatch in the final query and thus it results in a wrong SQL query, when user defined filter is selected for example.

As a workaround we implemented it like this:

$GLOBALS['TL_DCA']['tl_foo']['list']['sorting']['filter'][] = ['(foo NOT IN ('.implode(',', $ids).') AND 1=?)', 1];

so that there is no placeholder/value mismatch anymore. But it would be convenient (and would save some debugging time …) if one could simply define a filter without a placeholder like this:

$GLOBALS['TL_DCA']['tl_foo']['list']['sorting']['filter'][] = 'foo NOT IN ('.implode(',', $ids).')';

This PR would allow that.

[leofeyer]

I am fine with this change. We could even add it in Contao 4.9 IMHO. @contao/developers WDYT?

[leofeyer]

@fritzmg Can you please rebase this PR onto the 4.9 branch?

[fritzmg]

Done 👍

[fritzmg]

The failing test does not seem to be related to this PR.

[leofeyer]

Thank you @fritzmg.