symfony/http-kernel · error · LogicException

Unable to use expressions as the Symfony ExpressionLanguage…

Error message

Unable to use expressions as the Symfony ExpressionLanguage component is not installed. Try running "composer require symfony/expression-language".

What it means

CacheAttributeListener::getExpressionLanguage() lazily creates an ExpressionLanguage to evaluate attribute expressions. If the symfony/expression-language package is absent (class does not exist), it throws a LogicException telling the developer to install the component.

Solutions

1. Run "composer require symfony/expression-language".
2. Remove expression strings from Cache attributes so no ExpressionLanguage is needed.
3. Ensure the package is in the 'require' (not require-dev) section of composer.json for production use.

Example fix

// before (composer.json)
"require-dev": { "symfony/expression-language": "^7.0" }
// after
"require": { "symfony/expression-language": "^7.0" }

if (!class_exists(\Symfony\Component\ExpressionLanguage\ExpressionLanguage::class)) { throw new \RuntimeException('symfony/expression-language is required for Cache expressions'); }

try { $response = $controller(); } catch (\LogicException $e) { if (str_contains($e->getMessage(), 'ExpressionLanguage')) { /* install package or bypass attribute */ } throw $e; }

When it happens

Trigger: Dispatching a request to a controller with #[Cache(if: 'expression')] (or variables needing evaluation) when symfony/expression-language is not installed via Composer.

Common situations: Production builds pruning dev dependencies where expression-language is only in require-dev; new project forgetting the package while using cache attributes; framework upgrade introducing expression-based attribute options.

Understand the failure class

Background: "X is not installed. Please install it with pip install Y": missing optional dependency errors — ImportError/ValueError raised when a library's optional extra was never installed — this error's family across 22 libraries.

Related errors

• Cannot evaluate Expression for controllers since no…
• Request payload contains invalid "form" data.
• Unsupported format: " ".
• Request payload contains invalid
• Request payload contains invalid

AI-assisted analysis of symfony/http-kernel@aa3a39d728 (2026-09-13). Data as JSON: /api/errors/819a121d69f9e316. Report an issue: GitHub.

Appendix: source

Thrown at EventListener/CacheAttributeListener.php:285

    }

    /**
     * @param-immediately-invoked-callable $closureOrExpression
     */
    private function evaluate(string|Expression|\Closure $closureOrExpression, array $variables): mixed
    {
        if ($closureOrExpression instanceof \Closure) {
            return $closureOrExpression($variables['args'], $variables['request'], $variables['this']);
        }

        return $this->getExpressionLanguage()->evaluate($closureOrExpression, $variables);
    }

    private function getExpressionLanguage(): ExpressionLanguage
    {
        return $this->expressionLanguage ??= class_exists(ExpressionLanguage::class)
            ? new ExpressionLanguage()
            : throw new \LogicException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed. Try running "composer require symfony/expression-language".');
    }

    private function toSeconds(int|string $time): int
    {
        if (!is_numeric($time)) {
            $now = time();
            $time = strtotime($time, $now) - $now;
        }

        return $time;
    }
}

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