What causes "{% script with x %}: x is not an array" in getgrav/grav?

getgrav/grav · error · UnexpectedValueException

{% script with x %}: x is not an array

Error message

{% script with x %}: x is not an array

What it means

The {% script %} tag's compile() emits PHP that assigns the `with <expr>` clause to $attributes and throws UnexpectedValueException unless it is an array (when the clause is absent, $attributes defaults to []). The clause carries script tag attributes, so it must be a Twig mapping or array-valued expression; anything scalar/null aborts the compiled template at render time.

Source

Thrown at system/src/Grav/Common/Twig/Node/TwigNodeScript.php:64

    /**
     * Compiles the node to PHP.
     *
     * @param Compiler $compiler A Twig Compiler instance
     * @return void
     * @throws LogicException
     */
    public function compile(Compiler $compiler): void
    {
        $compiler->addDebugInfo($this);

        if ($this->hasNode('attributes')) {
            $compiler
                ->write('$attributes = ')
                ->subcompile($this->getNode('attributes'))
                ->raw(';' . PHP_EOL)
                ->write('if (!is_array($attributes)) {' . PHP_EOL)
                ->indent()
                ->write("throw new UnexpectedValueException('{% {$this->tagName} with x %}: x is not an array');" . PHP_EOL)
                ->outdent()
                ->write('}' . PHP_EOL);
        } else {
            $compiler->write('$attributes = [];' . PHP_EOL);
        }

        if ($this->hasNode('group')) {
            $compiler
                ->write('$group = ')
                ->subcompile($this->getNode('group'))
                ->raw(';' . PHP_EOL)
                ->write('if (!is_string($group)) {' . PHP_EOL)
                ->indent()
                ->write("throw new UnexpectedValueException('{% {$this->tagName} in x %}: x is not a string');" . PHP_EOL)
                ->outdent()
                ->write('}' . PHP_EOL);
        } else {
            $compiler->write('$group = \'head\';' . PHP_EOL);

View on GitHub (pinned to 6040efed04)

Solutions

Use a mapping literal: {% script 'app.js' in 'bottom' with { defer: true, async: false } %}
Ensure any variable used is an array: {% set attrs = {defer: true} %} then {% script 'app.js' with attrs %}
Default null variables: {% set attrs = attrs ?? {} %}

Example fix

{% set defer = true %}
{# before: scalar passed to with #}
{% script 'app.js' in 'bottom' with defer %}

{# after: mapping literal #}
{% script 'app.js' in 'bottom' with { defer: true } %}

Defensive patterns

Strategy: validation

Validate before calling

{# in Twig, guard the variable before the tag #}
{% set attrs = attrs is defined and attrs is iterable ? attrs : {} %}
{% script 'app.js' in 'bottom' with attrs %}

Try / catch

try { echo $twig->render($template, $data); } catch (UnexpectedValueException $e) { log_template_error($e); }

Prevention

Always write the with clause as a mapping literal: with { defer: true }
Default attribute variables with ?? {} before the tag
Review script tags after refactors that move attributes into variables

When it happens

Trigger: {% script 'app.js' in 'bottom' with defer %} where defer is a boolean variable; {% script 'app.js' with 'async' %} (bare string); a `with` variable that is null because the surrounding logic never populated it.

Common situations: Handwritten asset tags missing the attribute braces; attribute variables unset after template refactors; mixing up argument order so a non-array expression lands in the `with` slot.

Related errors

AI-assisted analysis of getgrav/grav@6040efed04 (2026-08-17). Data as JSON: /api/errors/04ad209f1811c646. Report an issue: GitHub.