ZF\Apigility\Admin\InputFilter\DocumentationInputFilter::isValid PHP Method

    public function isValid()
    {
        $this->messages = [];
        $isValid = true;
        if (!is_array($this->data)) {
            $this->messages['general']['invalidData'] = 'Documentation payload must be an array';
            return false;
        }
        foreach ($this->data as $key => $data) {
            if (in_array($key, $this->validHttpMethods)) {
                // valid HTTP method?
                if (isset($this->data['collection']) || isset($this->data['entity'])) {
                    $this->messages[$key][] = 'HTTP methods cannot be present when "collection" or "entity"' . ' is also present; please verify data for "' . $key . '"';
                    $isValid = false;
                    continue;
                }
                if (!$this->isValidHttpMethodDocumentation($data)) {
                    $isValid = false;
                    continue;
                }
                continue;
            }
            if (in_array($key, ['collection', 'entity'])) {
                // valid collection or entity
                if (!is_array($data)) {
                    $this->messages[$key][] = 'Collections and entities methods must be an array of HTTP methods;' . ' received invalid entry for "' . $key . '"';
                    $isValid = false;
                    continue;
                }
                foreach ($data as $subKey => $subData) {
                    if (in_array($subKey, $this->validHttpMethods)) {
                        if (!$this->isValidHttpMethodDocumentation($subData)) {
                            $isValid = false;
                            continue;
                        }
                    } elseif ($subKey === 'description') {
                        if (!is_string($subData)) {
                            $this->messages[$key][] = 'Description must be provided as a string;' . ' please verify description for "' . $subKey . '"';
                            $isValid = false;
                            continue;
                        }
                    } else {
                        $this->messages[$key][] = 'Key must be description or an HTTP indexed list;' . ' please verify documentation for "' . $subKey . '"';
                        $isValid = false;
                        continue;
                    }
                }
                continue;
            }
            if ($key === 'description') {
                // documentation checking
                if (!is_string($data)) {
                    $this->messages[$key][] = 'Description must be provided as a string;' . ' please verify description for "' . $key . '"';
                    $isValid = false;
                    continue;
                }
                continue;
            }
            // everything else is invalid
            $this->messages[$key][] = 'An invalid key was encountered in the top position for "' . $key . '"; ' . 'must be one of an HTTP method, collection, entity, or description';
            $isValid = false;
        }
        return $isValid;
    }