bcit-ci/CodeIgniter · error · InvalidArgumentException

Form_validation: set_rules() expect $rules to be string or a

Error message

Form_validation: set_rules() expect $rules to be string or array; $type given

What it means

Error "Form_validation: set_rules() expect $rules to be string or array; $type given" thrown in bcit-ci/CodeIgniter.

Source

Thrown at system/libraries/Form_validation.php:209

			return $this;
		}
		elseif ( ! isset($rules))
		{
			throw new BadMethodCallException('Form_validation: set_rules() called without a $rules parameter');
		}

		// No fields or no rules? Nothing to do...
		if ( ! is_string($field) OR $field === '' OR empty($rules))
		{
			throw new RuntimeException('Form_validation: set_rules() called with an empty $rules parameter');
		}
		elseif ( ! is_array($rules))
		{
			// BC: Convert pipe-separated rules string to an array
			if ( ! is_string($rules))
			{
				throw new InvalidArgumentException('Form_validation: set_rules() expect $rules to be string or array; '.gettype($rules).' given');
			}

			$rules = preg_split('/\|(?![^\[]*\])/', $rules);
		}

		// If the field label wasn't passed we use the field name
		$label = ($label === '') ? $field : $label;

		$indexes = array();

		// Is the field name an array? If it is an array, we break it apart
		// into its components so that we can fetch the corresponding POST data later
		if (($is_array = (bool) preg_match_all('/\[(.*?)\]/', $field, $matches)) === TRUE)
		{
			sscanf($field, '%[^[][', $indexes[0]);

			for ($i = 0, $c = count($matches[0]); $i < $c; $i++)
			{

View on GitHub (pinned to 3658d731ea)

When it happens

Trigger: Thrown at system/libraries/Form_validation.php:209 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bcit-ci/CodeIgniter@3658d731ea (2026-08-17). Data as JSON: /api/errors/f01bea9fe35d7baf. Report an issue: GitHub.