Controller_Validator_Abstract::applyRules PHP Method

    public function applyRules($field, $ruleset)
    {
        // Save previous values, just in case
        $acc = $this->acc;
        $crs = $this->current_ruleset;
        $this->bail_out = false;
        $this->acc = $this->get($field);
        $this->current_ruleset = $ruleset;
        while (!is_null($rule = $this->pullRule())) {
            $this->cast = false;
            $this->custom_error = null;
            if ($rule == 'required') {
                $is_required = true;
            }
            // For debugging
            $tmp = null;
            $this->consumed = array($rule);
            try {
                if ((is_object($rule) || is_array($rule)) && is_callable($rule)) {
                    $tmp = $rule($this, $this->acc, $field);
                } else {
                    // For to_XX rules
                    if (substr($rule, 0, 3) == 'to_') {
                        if (!$this->hasMethod('rule_' . $rule)) {
                            $rule = substr($rule, 3);
                        }
                        $this->cast = true;
                    }
                    if ($rule === '') {
                        if ($this->cast) {
                            $this->set($field, $this->acc);
                        }
                        continue;
                    }
                    $rule = $this->resolveRuleAlias($rule);
                    $tmp = $this->{'rule_' . $rule}($this->acc, $field);
                }
                if ($this->debug) {
                    echo "<font color=blue>rule_{$rule}({$this->acc}," . implode(',', $this->consumed) . ")={$tmp}</font><br/>";
                }
                if (!is_null($tmp)) {
                    $this->acc = $tmp;
                }
                if ($this->cast) {
                    $this->set($field, $tmp);
                }
                if ($this->bail_out) {
                    break;
                }
            } catch (\Exception_ValidityCheck $e) {
                if ($this->debug) {
                    echo "<font color=red>rule_{$rule}({$this->acc}," . implode(',', $this->consumed) . ') failed</font><br/>';
                }
                $this->acc = $acc;
                $this->current_ruleset = $crs;
                throw $e->setField($field)->addMoreInfo('val', $this->acc)->addMoreInfo('rule', $rule);
            }
        }
        $this->acc = $acc;
        $this->current_ruleset = $crs;
    }