function addFormRule($rule)
    {
        if (!is_callable($rule)) {
            return self::raiseError(null, QUICKFORM_INVALID_RULE, null, E_USER_WARNING, 'Callback function does not exist in HTML_QuickForm::addFormRule()', 'HTML_QuickForm_Error', true);
        }
        $this->_formRules[] = $rule;
    }
function addFormRule($rule)
    {
        if (!is_callable($rule)) {
            return self::raiseError(null, QUICKFORM_INVALID_RULE, null, E_USER_WARNING, 'Callback function does not exist in HTML_QuickForm::addFormRule()', 'HTML_QuickForm_Error', true);
        }
        $this->_formRules[] = $rule;
    }
function addFormRule ( $ rule ) { if ( ! is_callable ( $ rule ) ) { return self :: raiseError ( null , QUICKFORM_INVALID_RULE , null , E_USER_WARNING , 'Callback function does not exist in HTML_QuickForm::addFormRule()' , 'HTML_QuickForm_Error' , true ) ; } $ this -> _formRules [ ] = $ rule ; }
Adds a global validation rule

This should be used when for a rule involving several fields or if
you want to use some completely custom validation for your form.
The rule function/method should return true in case of successful
validation and array('element name' => 'error') when there were errors.

@access   public
@param    mixed   Callback, either function name or array(&$object, 'method')
@throws   HTML_QuickForm_Error
Adds a global validation rule