class NullCoalesceExpression
Hierarchy
- class \Twig\Node\Node implements \Twig\Node\Countable, \Twig\Node\IteratorAggregate
- class \Twig\Node\Expression\AbstractExpression extends \Twig\Node\Node
- class \Twig\Node\Expression\ConditionalExpression extends \Twig\Node\Expression\AbstractExpression
- class \Twig\Node\Expression\NullCoalesceExpression extends \Twig\Node\Expression\ConditionalExpression
- class \Twig\Node\Expression\ConditionalExpression extends \Twig\Node\Expression\AbstractExpression
- class \Twig\Node\Expression\AbstractExpression extends \Twig\Node\Node
Expanded class hierarchy of NullCoalesceExpression
1 file declares its use of NullCoalesceExpression
- CoreExtension.php in vendor/
twig/ twig/ src/ Extension/ CoreExtension.php
File
-
vendor/
twig/ twig/ src/ Node/ Expression/ NullCoalesceExpression.php, line 23
Namespace
Twig\Node\ExpressionView source
class NullCoalesceExpression extends ConditionalExpression {
/**
* @param AbstractExpression $left
* @param AbstractExpression $right
*/
public function __construct(Node $left, Node $right, int $lineno) {
if (!$left instanceof AbstractExpression) {
trigger_deprecation('twig/twig', '3.15', 'Not passing a "%s" instance to the "left" argument of "%s" is deprecated ("%s" given).', AbstractExpression::class, static::class, get_class($left));
}
if (!$right instanceof AbstractExpression) {
trigger_deprecation('twig/twig', '3.15', 'Not passing a "%s" instance to the "right" argument of "%s" is deprecated ("%s" given).', AbstractExpression::class, static::class, get_class($right));
}
$test = new DefinedTest(clone $left, new TwigTest('defined'), new EmptyNode(), $left->getTemplateLine());
// for "block()", we don't need the null test as the return value is always a string
if (!$left instanceof BlockReferenceExpression) {
$test = new AndBinary($test, new NotUnary(new NullTest($left, new TwigTest('null'), new EmptyNode(), $left->getTemplateLine()), $left->getTemplateLine()), $left->getTemplateLine());
}
parent::__construct($test, $left, $right, $lineno);
}
public function compile(Compiler $compiler) : void {
/*
* This optimizes only one case. PHP 7 also supports more complex expressions
* that can return null. So, for instance, if log is defined, log("foo") ?? "..." works,
* but log($a["foo"]) ?? "..." does not if $a["foo"] is not defined. More advanced
* cases might be implemented as an optimizer node visitor, but has not been done
* as benefits are probably not worth the added complexity.
*/
if ($this->getNode('expr2') instanceof NameExpression) {
$this->getNode('expr2')
->setAttribute('always_defined', true);
$compiler->raw('((')
->subcompile($this->getNode('expr2'))
->raw(') ?? (')
->subcompile($this->getNode('expr3'))
->raw('))');
}
else {
parent::compile($compiler);
}
}
}