{"record":{"id":"e81205dfb980892e","repo":"getgrav/grav","slug":"argument-should-be-either-header-variable-name-or","errorCode":null,"errorMessage":"Argument should be either header variable name or array of parameters","messagePattern":"Argument should be either header variable name or array of parameters","errorType":"validation","errorClass":"InvalidArgumentException","httpStatus":null,"severity":"error","filePath":"system/src/Grav/Common/Page/Page.php","lineNumber":2915,"sourceCode":"        return $pages->find($url, $all);\n    }\n\n    /**\n     * Get a collection of pages in the current context.\n     *\n     * @param string|array $params\n     * @param bool $pagination\n     *\n     * @return PageCollectionInterface|Collection\n     * @throws InvalidArgumentException\n     */\n    public function collection($params = 'content', $pagination = true)\n    {\n        if (is_string($params)) {\n            // Look into a page header field.\n            $params = (array)$this->value('header.' . $params);\n        } elseif (!is_array($params)) {\n            throw new InvalidArgumentException('Argument should be either header variable name or array of parameters');\n        }\n\n        $params['filter'] = ($params['filter'] ?? []) + ['translated' => true];\n        $context = [\n            'pagination' => $pagination,\n            'self' => $this\n        ];\n\n        /** @var Pages $pages */\n        $pages = Grav::instance()['pages'];\n\n        return $pages->getCollection($params, $context);\n    }\n\n    /**\n     * @param string|array $value\n     * @param bool $only_published\n     * @return PageCollectionInterface|Collection","sourceCodeStart":2897,"sourceCodeEnd":2933,"githubUrl":"https://github.com/getgrav/grav/blob/6040efed04efa69b8209448ed81308e7c24147c2/system/src/Grav/Common/Page/Page.php#L2897-L2933","documentation":"Error \"Argument should be either header variable name or array of parameters\" thrown in getgrav/grav.","triggerScenarios":"Thrown at system/src/Grav/Common/Page/Page.php:2915 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"6040efed04efa69b8209448ed81308e7c24147c2","analyzedAt":"2026-08-17T05:07:31.593Z","schemaVersion":2},"datasetVersion":"2026-08-17T09:17:11.063Z"}