DoIfMapper / DoIfSingleClosureMapper

Conditional control-flow mappers. A condition (a bool or a closure returning bool) is evaluated, and when it is true the mapper can:

• abort the bind (abort: true) — the result becomes invalid and later mappers are skipped;
• skip the following mappers on the same prop (skipNextMappers: true) — the value passes through unchanged;
• change existence / logical state of the bindables (chExists, chLogical), optionally cascading to descendants (cascaded: true).

There are two shapes:

The deleteIf family — Mappers::deleteIf($cond), deleteIfValueClosure($closure), deleteIfBindableClosure($closure) — are shortcuts that mark the bindable (and, by default, its descendants) non-existing when the condition is true.

Example: skipping a mapper when the value is null​

$result = Bind::attrs(['prop' => null])->prop('prop',
        Mappers::doIfNull(skipNextMappers: true),
        Mappers::value(fn (string $v) => $v . '-x'))
        ->toArray()->exec();
var_dump($result->get());

Output:

array(1) {
  ["prop"]=>
  NULL
}

Because the value is null, doIfNull skips the following value mapper, so the value passes through unchanged. With ['prop' => 'holeradio'] the value mapper would run and produce 'holeradio-x'.

Example: aborting the bind from a boundary condition​

$result = Bind::attrs(['prop' => 'holeradio'])->prop('prop',
        Mappers::value(fn (string $v) => $v . '-1'),
        Mappers::doIf(fn (BindBoundary $b) => true, abort: true),
        Mappers::value(function () { /* never reached */ }))
        ->toArray()->exec();
var_dump($result->isValid()); // false

Output:

bool(false)

The doIf condition is true, so abort: true marks the result invalid and the third mapper is never executed.