quarkusio/quarkus · error · IllegalArgumentException

n-th parameter is missing

Error message

n-th parameter is missing

What it means

Qute's ArrayResolver supports the array 'take' method (take(n) returns the first n elements). If the expression provides no parameters, resolver throws IllegalArgumentException("n-th parameter is missing").

Source

Thrown at independent-projects/qute/core/src/main/java/io/quarkus/qute/ValueResolvers.java:406

        static final String GET = "get";

        public ArrayResolver() {
            super(Set.of(LENGTH, SIZE, "${index}"), //
                    Set.of(TAKE + "(${index})", TAKE_LAST + "(${index})", GET + "(${index})"));
        }

        public boolean appliesTo(EvalContext context) {
            return context.getBase() != null && context.getBase().getClass().isArray();
        }

        @Override
        public CompletionStage<Object> resolve(EvalContext context) {
            String name = context.getName();
            if (name.equals(LENGTH) || name.equals(SIZE)) {
                return CompletedStage.of(Array.getLength(context.getBase()));
            } else if (name.equals(TAKE)) {
                if (context.getParams().isEmpty()) {
                    throw new IllegalArgumentException("n-th parameter is missing");
                }
                Expression indexExpr = context.getParams().get(0);
                if (indexExpr.isLiteral()) {
                    Object literalValue = indexExpr.getLiteral();
                    if (literalValue instanceof Integer) {
                        return CompletedStage.of(takeArray((Integer) literalValue, context.getBase()));
                    }
                    return Results.notFound(context);
                } else {
                    return context.evaluate(indexExpr).thenCompose(n -> {
                        if (n instanceof Integer) {
                            return CompletedStage.of(takeArray((Integer) n, context.getBase()));
                        }
                        return Results.notFound(context);
                    });
                }
            } else if (name.equals(TAKE_LAST)) {
                if (context.getParams().isEmpty()) {

View on GitHub (pinned to e1c734241f)

Solutions

1. Pass a literal or expression index: {myArray.take(3)}.
2. If the index comes from a variable, verify it resolves and is passed as a parameter: {myArray.take(count)}.
3. Guard the template: only call take when a count is available, e.g. {#if count}{myArray.take(count)}{/if}.

Example fix

// before (template)
{items.take}

// after (template)
{items.take(3)}

// in template data, before rendering, ensure the argument exists:
if (count == null) {
    throw new IllegalStateException("take(n) requires a count parameter");
}

static boolean hasTakeParams(String expr) {
    return expr.matches(".*\\.take\\s*\\(.+\\).*");
}

try {
    // render template that uses take
} catch (IllegalArgumentException e) {
    if ("n-th parameter is missing".equals(e.getMessage())) {
        // fix expression to pass an index: items.take(n)
    } else {
        throw e;
    }
}

When it happens

Trigger: Evaluating an expression like {myArray.take} or take() with an empty/missing argument in a template, where context.getParams() is empty for the TAKE method name.

Common situations: Typos such as writing take without parentheses-argument, dynamically built expressions where the index variable failed to render/resolve to a parameter, copy-pasted templates missing the argument.

Related errors

• Invalid identifier found: [id]
• Literal must not be null
• Only Latin characters are supported:
• Replacement ID must be in range [0, 15] but was:
• Unexpected tag: " + tag

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/4f4f63a681362808. Report an issue: GitHub.