Change Event service

Change Event provides specific field-by-field breakdowns of exactly what changed in your account. When reporting on a create operation, all new field values are returned, and when reporting on an update operation, both the new and the old values are returned so you can get a complete picture of individual changes.

Additionally, you can see which interface was used to make the change (such as the Google Ads API or the web UI), as well as what user made the change (assuming that information would be visible in the Change History of the web UI as well).

Change Event types

The Change Event service currently tracks changes of the following resource types:

Resource type Value
Ad AD
Ad group AD_GROUP
Ad group ad AD_GROUP_AD
Ad group bid modifier AD_GROUP_BID_MODIFIER
Ad group criterion AD_GROUP_CRITERION
Campaign CAMPAIGN
Campaign budget CAMPAIGN_BUDGET
Campaign criterion CAMPAIGN_CRITERION
Ad group feed AD_GROUP_FEED
Campaign feed CAMPAIGN_FEED
Feed FEED
Feed item FEED_ITEM

Getting changes

The list of changes must be filtered by date, and the query must include a LIMIT clause. The date range must be within the past 30 days. The limit must be at most 10,000 rows. If you're interested in more than 10,000 results, make a note of the timestamp of the last entry in the returned result set, and then set your date range on the following query to start after that time. This will allow you to continue processing where you left off.

The following example demonstrates how to fetch change events and process them, including determining who made the change, which interface they used to make the change, and the old and new values of each field in the change:

Java

private void runExample(GoogleAdsClient googleAdsClient, long customerId) {
  // Defines a GAQL query to retrieve change_event instances from the last 14 days.
  String query =
      String.format(
          "SELECT"
              + "  change_event.resource_name,"
              + "  change_event.change_date_time,"
              + "  change_event.change_resource_name,"
              + "  change_event.user_email,"
              + "  change_event.client_type,"
              + "  change_event.change_resource_type,"
              + "  change_event.old_resource,"
              + "  change_event.new_resource,"
              + "  change_event.resource_change_operation,"
              + "  change_event.changed_fields "
              + "FROM "
              + "  change_event "
              + "WHERE "
              + "  change_event.change_date_time <= '%s' "
              + "  AND change_event.change_date_time >= '%s' "
              + "ORDER BY"
              + "  change_event.change_date_time DESC "
              + "LIMIT 5",
          LocalDate.now().toString("YYYY-MM-dd"),
          LocalDate.now().minusDays(14).toString("YYYY-MM-dd"));

  // Creates a GoogleAdsServiceClient instance.
  try (GoogleAdsServiceClient client =
      googleAdsClient.getLatestVersion().createGoogleAdsServiceClient()) {
    // Issues the search query.
    SearchPagedResponse response = client.search(String.valueOf(customerId), query);

    // Processes the rows of the response.
    for (GoogleAdsRow row : response.iterateAll()) {
      ChangeEvent event = row.getChangeEvent();

      // Prints some general information about the change event.
      System.out.printf(
          "On '%s', user '%s' used interface '%s' to perform a(n) '%s' operation on a '%s' with"
              + " resource name '%s'.%n",
          event.getChangeDateTime(),
          event.getUserEmail(),
          event.getClientType(),
          event.getResourceChangeOperation(),
          event.getChangeResourceType(),
          event.getResourceName());

      // Prints some detailed information about update and create operations.
      if (event.getResourceChangeOperation() == ResourceChangeOperation.UPDATE
          || event.getResourceChangeOperation() == ResourceChangeOperation.CREATE) {
        // Retrieves the entity that was changed.
        Optional<Message> oldResource =
            getResourceByType(event.getOldResource(), event.getChangeResourceType());
        Optional<Message> newResource =
            getResourceByType(event.getNewResource(), event.getChangeResourceType());

        // Prints the old and new values for each field that was updated/created.
        for (String changedPath : row.getChangeEvent().getChangedFields().getPathsList()) {
          // Uses the FieldMasks utility to retrieve a value from a . delimited path.
          List<? extends Object> oldValue =
              oldResource.isPresent()
                  ? FieldMasks.getFieldValue(changedPath, oldResource.get())
                  : Collections.emptyList();
          List<? extends Object> newValue =
              newResource.isPresent()
                  ? FieldMasks.getFieldValue(changedPath, newResource.get())
                  : Collections.emptyList();
          // Prints different messages for UPDATE and CREATE cases.
          if (event.getResourceChangeOperation() == ResourceChangeOperation.UPDATE) {
            System.out.printf("\t %s changed from %s to %s.%n", changedPath, oldValue, newValue);
          } else if (event.getResourceChangeOperation() == ResourceChangeOperation.CREATE) {
            System.out.printf("\t %s set to %s.%n", changedPath, newValue);
          }
        }
      }
    }
  }
}
      

C#

public void Run(GoogleAdsClient client, long customerId)
{
    // Get the GoogleAdsService.
    GoogleAdsServiceClient googleAdsService = client.GetService(
        Services.V6.GoogleAdsService);

    // Construct a query to find details for recent changes in your account.
    // The LIMIT clause is required for the change_event resource.
    // The maximum size is 10000, but a low limit was set here for demonstrative
    // purposes.
    // The WHERE clause on change_date_time is also required. It must specify a
    // window of at most 30 days within the past 30 days.

    string startDate = DateTime.Today.Subtract(TimeSpan.FromDays(25)).ToString("yyyyMMdd");
    string endDate = DateTime.Today.Add(TimeSpan.FromDays(1)).ToString("yyyyMMdd");
    string searchQuery = $@"
        SELECT
            change_event.resource_name,
            change_event.change_date_time,
            change_event.change_resource_name,
            change_event.user_email,
            change_event.client_type,
            change_event.change_resource_type,
            change_event.old_resource,
            change_event.new_resource,
            change_event.resource_change_operation,
            change_event.changed_fields
        FROM
            change_event
        WHERE
            change_event.change_date_time >= '{startDate}' AND
            change_event.change_date_time <= '{endDate}'
        ORDER BY
            change_event.change_date_time DESC
        LIMIT 5";

    try
    {
        // Issue a search request.
        googleAdsService.SearchStream(customerId.ToString(), searchQuery,
            delegate (SearchGoogleAdsStreamResponse resp)
            {
                // Display the results.
                foreach (GoogleAdsRow googleAdsRow in resp.Results)
                {
                    ChangeEvent changeEvent = googleAdsRow.ChangeEvent;
                    ChangedResource oldResource = changeEvent.OldResource;
                    ChangedResource newResource = changeEvent.NewResource;

                    bool knownResourceType = true;
                    IMessage oldResourceEntity = null;
                    IMessage newResourceEntity = null;
                    switch (changeEvent.ChangeResourceType)
                    {
                        case ChangeEventResourceType.Ad:
                            oldResourceEntity = oldResource.Ad;
                            newResourceEntity = newResource.Ad;
                            break;

                        case ChangeEventResourceType.AdGroup:
                            oldResourceEntity = oldResource.AdGroup;
                            newResourceEntity = newResource.AdGroup;
                            break;

                        case ChangeEventResourceType.AdGroupAd:
                            oldResourceEntity = oldResource.AdGroupAd;
                            newResourceEntity = newResource.AdGroupAd;
                            break;

                        case ChangeEventResourceType.AdGroupCriterion:
                            oldResourceEntity = oldResource.AdGroupCriterion;
                            newResourceEntity = newResource.AdGroupCriterion;
                            break;

                        case ChangeEventResourceType.AdGroupBidModifier:
                            oldResourceEntity = oldResource.AdGroupBidModifier;
                            newResourceEntity = newResource.AdGroupBidModifier;
                            break;

                        case ChangeEventResourceType.Campaign:
                            oldResourceEntity = oldResource.Campaign;
                            newResourceEntity = newResource.Campaign;
                            break;

                        case ChangeEventResourceType.CampaignBudget:
                            oldResourceEntity = oldResource.CampaignBudget;
                            newResourceEntity = newResource.CampaignBudget;
                            break;

                        case ChangeEventResourceType.CampaignCriterion:
                            oldResourceEntity = oldResource.CampaignCriterion;
                            newResourceEntity = newResource.CampaignCriterion;
                            break;

                        case ChangeEventResourceType.AdGroupFeed:
                            oldResourceEntity = oldResource.AdGroupFeed;
                            newResourceEntity = newResource.AdGroupFeed;
                            break;

                        case ChangeEventResourceType.CampaignFeed:
                            oldResourceEntity = oldResource.CampaignFeed;
                            newResourceEntity = newResource.CampaignFeed;
                            break;

                        case ChangeEventResourceType.Feed:
                            oldResourceEntity = oldResource.Feed;
                            newResourceEntity = newResource.Feed;
                            break;

                        case ChangeEventResourceType.FeedItem:
                            oldResourceEntity = oldResource.FeedItem;
                            newResourceEntity = newResource.FeedItem;
                            break;

                        default:
                            knownResourceType = false;
                            break;
                    }

                    if (!knownResourceType)
                    {
                        Console.WriteLine($"Unknown change_resource_type " +
                            $"'{changeEvent.ChangeResourceType}'.");
                        continue;
                    }

                    Console.WriteLine($"On #{changeEvent.ChangeDateTime}, user " +
                        $"{changeEvent.UserEmail} used interface {changeEvent.ClientType} " +
                        $"to perform a(n) '{changeEvent.ResourceChangeOperation}' " +
                        $"operation on a '{changeEvent.ChangeResourceType}' with " +
                        $"resource name {changeEvent.ChangeResourceName}.");

                    foreach (string fieldMaskPath in changeEvent.ChangedFields.Paths)
                    {
                        if (changeEvent.ResourceChangeOperation ==
                            ResourceChangeOperation.Create)
                        {
                            object newValue = FieldMasks.GetFieldValue(
                                fieldMaskPath, newResourceEntity);
                            Console.WriteLine($"\t{fieldMaskPath} set to '{newValue}'.");
                        }
                        else if (changeEvent.ResourceChangeOperation ==
                            ResourceChangeOperation.Update)
                        {
                            object oldValue = FieldMasks.GetFieldValue(fieldMaskPath,
                                oldResourceEntity);
                            object newValue = FieldMasks.GetFieldValue(fieldMaskPath,
                                newResourceEntity);

                            Console.WriteLine($"\t{fieldMaskPath} changed from " +
                                $"'{oldValue}' to '{newValue}'.");
                        }
                    }
                }
            });
    }
    catch (GoogleAdsException e)
    {
        Console.WriteLine("Failure:");
        Console.WriteLine($"Message: {e.Message}");
        Console.WriteLine($"Failure: {e.Failure}");
        Console.WriteLine($"Request ID: {e.RequestId}");
        throw;
    }
}
      

PHP

public static function runExample(GoogleAdsClient $googleAdsClient, int $customerId)
{
    $googleAdsServiceClient = $googleAdsClient->getGoogleAdsServiceClient();

    // Constructs a query to find details for recent changes in your account.
    // The LIMIT clause is required for the change_event resource.
    // The maximum size is 10000, but a low limit was set here for demonstrative
    // purposes.
    // The WHERE clause on change_date_time is also required. It must specify a
    // window of at most 30 days within the past 30 days.
    $query = 'SELECT change_event.resource_name, '
        . 'change_event.change_date_time, '
        . 'change_event.change_resource_name, '
        . 'change_event.user_email, '
        . 'change_event.client_type, '
        . 'change_event.change_resource_type, '
        . 'change_event.old_resource, '
        . 'change_event.new_resource, '
        . 'change_event.resource_change_operation, '
        . 'change_event.changed_fields '
        . 'FROM change_event '
        . sprintf(
            'WHERE change_event.change_date_time <= %s ',
            date_format(new DateTime('+1 day'), 'Ymd')
        ) . sprintf(
            'AND change_event.change_date_time >= %s ',
            date_format(new DateTime('-14 days'), 'Ymd')
        ) . 'ORDER BY change_event.change_date_time DESC '
        . 'LIMIT 5';
    // Issues a search request by specifying page size.
    // The page size is superfluous with the default limit set above, but it's
    // shown here since it's a good practice to use a reasonable page size when
    // you set a higher limit.
    $response =
        $googleAdsServiceClient->search($customerId, $query, ['pageSize' => self::PAGE_SIZE]);

    // Iterates over all rows in all pages and prints the requested field values for
    // the change event in each row.
    foreach ($response->iterateAllElements() as $googleAdsRow) {
        /** @var GoogleAdsRow $googleAdsRow */
        $changeEvent = $googleAdsRow->getChangeEvent();
        $oldResource = $changeEvent->getOldResource();
        $newResource = $changeEvent->getNewResource();

        $isResourceTypeKnown = true;
        $oldResourceEntity = null;
        $newResourceEntity = null;
        switch ($changeEvent->getChangeResourceType()) {
            case ChangeEventResourceType::AD:
                $oldResourceEntity = $oldResource->getAd();
                $newResourceEntity = $newResource->getAd();
                break;
            case ChangeEventResourceType::AD_GROUP:
                $oldResourceEntity = $oldResource->getAdGroup();
                $newResourceEntity = $newResource->getAdGroup();
                break;
            case ChangeEventResourceType::AD_GROUP_AD:
                $oldResourceEntity = $oldResource->getAdGroupAd();
                $newResourceEntity = $newResource->getAdGroupAd();
                break;
            case ChangeEventResourceType::AD_GROUP_CRITERION:
                $oldResourceEntity = $oldResource->getAdGroupCriterion();
                $newResourceEntity = $newResource->getAdGroupCriterion();
                break;
            case ChangeEventResourceType::AD_GROUP_BID_MODIFIER:
                $oldResourceEntity = $oldResource->getAdGroupBidModifier();
                $newResourceEntity = $newResource->getAdGroupBidModifier();
                break;
            case ChangeEventResourceType::CAMPAIGN:
                $oldResourceEntity = $oldResource->getCampaign();
                $newResourceEntity = $newResource->getCampaign();
                break;
            case ChangeEventResourceType::CAMPAIGN_BUDGET:
                $oldResourceEntity = $oldResource->getCampaignBudget();
                $newResourceEntity = $newResource->getCampaignBudget();
                break;
            case ChangeEventResourceType::CAMPAIGN_CRITERION:
                $oldResourceEntity = $oldResource->getCampaignCriterion();
                $newResourceEntity = $newResource->getCampaignCriterion();
                break;
            case ChangeEventResourceType::AD_GROUP_FEED:
                $oldResourceEntity = $oldResource->getAdGroupFeed();
                $newResourceEntity = $newResource->getAdGroupFeed();
                break;
            case ChangeEventResourceType::CAMPAIGN_FEED:
                $oldResourceEntity = $oldResource->getCampaignFeed();
                $newResourceEntity = $newResource->getCampaignFeed();
                break;
            case ChangeEventResourceType::FEED:
                $oldResourceEntity = $oldResource->getFeed();
                $newResourceEntity = $newResource->getFeed();
                break;
            case ChangeEventResourceType::FEED_ITEM:
                $oldResourceEntity = $oldResource->getFeedItem();
                $newResourceEntity = $newResource->getFeedItem();
                break;
            default:
                $isResourceTypeKnown = false;
                break;
        }
        if (!$isResourceTypeKnown) {
            printf(
                "Unknown change_resource_type %s.%s",
                ChangeEventResourceType::name($changeEvent->getChangeResourceType()),
                PHP_EOL
            );
        }
        $resourceChangeOperation = $changeEvent->getResourceChangeOperation();
        printf(
            "On %s, user '%s' used interface '%s' to perform a(n) '%s' operation on a '%s' "
            . "with resource name '%s'.%s",
            $changeEvent->getChangeDateTime(),
            $changeEvent->getUserEmail(),
            ChangeClientType::name($changeEvent->getClientType()),
            ResourceChangeOperation::name($resourceChangeOperation),
            ChangeEventResourceType::name($changeEvent->getChangeResourceType()),
            $changeEvent->getChangeResourceName(),
            PHP_EOL
        );

        if (
            $resourceChangeOperation !== ResourceChangeOperation::CREATE
            && $resourceChangeOperation !== ResourceChangeOperation::UPDATE
        ) {
            continue;
        }
        foreach ($changeEvent->getChangedFields()->getPaths() as $path) {
            $newValueStr =
                self::convertToString(FieldMasks::getFieldValue($path, $newResourceEntity));
            if ($resourceChangeOperation === ResourceChangeOperation::CREATE) {
                printf("'$path' set to '%s'.%s", $newValueStr, PHP_EOL);
            } elseif ($resourceChangeOperation === ResourceChangeOperation::UPDATE) {
                printf(
                    "'$path' changed from '%s' to '%s'.%s",
                    self::convertToString(FieldMasks::getFieldValue($path, $oldResourceEntity)),
                    $newValueStr,
                    PHP_EOL
                );
            }
        }
    }
}

/**
 * Converts the specified value to string.
 *
 * @param mixed $value the value to be converted to string
 * @return string the value in string
 */
private static function convertToString($value)
{
    if (is_null($value)) {
        return 'no value';
    }
    if (gettype($value) === 'boolean') {
        return $value ? 'true' : 'false';
    } elseif (gettype($value) === 'object' && get_class($value) === RepeatedField::class) {
        return json_encode(iterator_to_array($value->getIterator()));
    } else {
        return strval($value);
    }
}
      

Python

This example is not yet available in Python; you can take a look at the other languages.
    

Ruby

def get_change_details(customer_id)
  # GoogleAdsClient will read a config file from
  # ENV['HOME']/google_ads_config.rb when called without parameters
  client = Google::Ads::GoogleAds::GoogleAdsClient.new

  # Construct a query to find details for recent changes in your account.
  # The LIMIT clause is required for the change_event resource.
  # The maximum size is 10000, but a low limit was set here for demonstrative
  # purposes.
  # The WHERE clause on change_date_time is also required. It must specify a
  # window of at most 30 days within the past 30 days.
  query = <<~QUERY
    SELECT
      change_event.resource_name,
      change_event.change_date_time,
      change_event.change_resource_name,
      change_event.user_email,
      change_event.client_type,
      change_event.change_resource_type,
      change_event.old_resource,
      change_event.new_resource,
      change_event.resource_change_operation,
      change_event.changed_fields
    FROM
      change_event
    WHERE
      change_event.change_date_time <= '#{(Date.today + 1).to_s}'
      AND change_event.change_date_time >= '#{(Date.today - 14).to_s}'
    ORDER BY
      change_event.change_date_time DESC
    LIMIT 5
  QUERY

  # Execute the query to fetch results from the API.
  response = client.service.google_ads.search(
    customer_id: customer_id,
    query: query,
    # The page size is superfluous with the default limit set above, but it's
    # shown here since it's a good practice to use a reasonable page size when
    # you set a higher limit.
    page_size: PAGE_SIZE
  )

  # Process the results and output changes.
  response.each do |row|
    event = row.change_event
    old_resource, new_resource = case event.change_resource_type
    when :AD
      [event.old_resource.ad, event.new_resource.ad]
    when :AD_GROUP
      [event.old_resource.ad_group, event.new_resource.ad_group]
    when :AD_GROUP_AD
      [event.old_resource.ad_group_ad, event.new_resource.ad_group_ad]
    when :AD_GROUP_CRITERION
      [event.old_resource.ad_group_criterion, event.new_resource.ad_group_criterion]
    when :AD_GROUP_BID_MODIFIER
      [event.old_resource.ad_group_bid_modifier, event.new_resource.ad_group_bid_modifier]
    when :CAMPAIGN
      [event.old_resource.campaign, event.new_resource.campaign]
    when :CAMPAIGN_BUDGET
      [event.old_resource.campaign_budget, event.new_resource.campaign_budget]
    when :CAMPAIGN_CRITERION
      [event.old_resource.campaign_criterion, event.new_resource.campaign_criterion]
    when :AD_GROUP_FEED
      [event.old_resource.ad_group_feed, event.new_resource.ad_group_feed]
    when :CAMPAIGN_FEED
      [event.old_resource.campaign_feed, event.new_resource.campaign_feed]
    when :FEED
      [event.old_resource.feed, event.new_resource.feed]
    when :FEED_ITEM
      [event.old_resource.feed_item, event.new_resource.feed_item]
    else
      puts "Unknown change_resource_type #{event.change_resource_type}."
      next
    end
    puts "On #{event.change_date_time}, user #{event.user_email} used interface " \
      "#{event.client_type} to perform a(n) #{event.resource_change_operation} " \
      "operation on a #{event.change_resource_type} with resource name " \
      "#{event.change_resource_name}."
    if [:UPDATE, :CREATE].include? event.resource_change_operation
      event.changed_fields.paths.each do |changed_field|
        new_value = get_value_from_path(changed_field, new_resource)
        if :CREATE == event.resource_change_operation
          puts "\t#{changed_field} set to '#{new_value}'."
        else
          old_value = get_value_from_path(changed_field, old_resource)
          puts "\t#{changed_field} changed from '#{old_value}' to '#{new_value}'."
        end
      end
    end
  end
end

# Given the string value of a path from the response, look up the value of the
# field located at that path on the given object.
def get_value_from_path(path, object)
  path.split(".").inject(object) {|obj, key| obj.send(key)}
end
      

Perl

sub get_change_details {
  my ($api_client, $customer_id) = @_;

  # Construct a query to find details for recent changes in your account.
  # The LIMIT clause is required for the change_event resource.
  # The maximum size is 10000, but a low limit was set here for demonstrative
  # purposes.
  # The WHERE clause on change_date_time is also required. It must specify a
  # window of at most 30 days within the past 30 days.
  my $search_query =
    "SELECT change_event.resource_name, change_event.change_date_time, " .
    "change_event.change_resource_name, change_event.user_email, " .
    "change_event.client_type, change_event.change_resource_type, " .
    "change_event.old_resource, change_event.new_resource, " .
    "change_event.resource_change_operation, change_event.changed_fields " .
    "FROM change_event " .
    "WHERE change_event.change_date_time DURING LAST_14_DAYS " .
    "ORDER BY change_event.change_date_time DESC LIMIT 5";

  # Create a search Google Ads request that will retrieve all change events using
  # pages of the specified page size.
  my $search_request =
    Google::Ads::GoogleAds::V6::Services::GoogleAdsService::SearchGoogleAdsRequest
    ->new({
      customerId => $customer_id,
      query      => $search_query,
      # The page size is superfluous with the default limit set above, but it's
      # shown here since it's a good practice to use a reasonable page size
      # when you set a higher limit.
      pageSize => PAGE_SIZE
    });

  # Get the GoogleAdsService.
  my $google_ads_service = $api_client->GoogleAdsService();

  my $iterator = Google::Ads::GoogleAds::Utils::SearchGoogleAdsIterator->new({
    service => $google_ads_service,
    request => $search_request
  });

  # Iterate over all rows in all pages and print the requested field values for
  # the change event in each row.
  while ($iterator->has_next) {
    my $google_ads_row = $iterator->next;

    my $change_event = $google_ads_row->{changeEvent};
    printf "On %s, user %s used interface %s to perform a(n) %s operation " .
      "on a %s with resource name '%s'.\n", $change_event->{changeDateTime},
      $change_event->{userEmail}, $change_event->{clientType},
      $change_event->{resourceChangeOperation},
      $change_event->{changeResourceType}, $change_event->{changeResourceName};

    if (grep /$change_event->{resourceChangeOperation}/, (CREATE, UPDATE)) {
      my ($old_resource, $new_resource) =
        __get_changed_resources_for_resource_type($change_event);

      foreach my $changed_field (split /,/, $change_event->{changedFields}) {
        my $new_value = get_field_value($new_resource, $changed_field) || "";
        if ($change_event->{resourceChangeOperation} eq CREATE) {
          print "\t$changed_field set to '$new_value'.\n";
        } else {
          my $old_value = get_field_value($old_resource, $changed_field) || "";
          print "\t$changed_field changed from '$old_value' to '$new_value'.\n";
        }
      }
    }
  }

  return 1;
}

# This method returns the old resource and new resource based on the change
# resource type of a change event.
sub __get_changed_resources_for_resource_type {
  my $change_event  = shift;
  my $resource_type = $change_event->{changeResourceType};
  if ($resource_type eq AD) {
    return $change_event->{oldResource}{ad}, $change_event->{newResource}{ad};
  } elsif ($resource_type eq AD_GROUP) {
    return $change_event->{oldResource}{adGroup},
      $change_event->{newResource}{adGroup};
  } elsif ($resource_type eq AD_GROUP_AD) {
    return $change_event->{oldResource}{adGroupAd},
      $change_event->{newResource}{adGroupAd};
  } elsif ($resource_type eq AD_GROUP_CRITERION) {
    return $change_event->{oldResource}{adGroupCriterion},
      $change_event->{newResource}{adGroupCriterion};
  } elsif ($resource_type eq AD_GROUP_BID_MODIFIER) {
    return $change_event->{oldResource}{adGroupBidModifier},
      $change_event->{newResource}{adGroupBidModifier};
  } elsif ($resource_type eq CAMPAIGN) {
    return $change_event->{oldResource}{campaign},
      $change_event->{newResource}{campaign};
  } elsif ($resource_type eq CAMPAIGN_BUDGET) {
    return $change_event->{oldResource}{campaignBudget},
      $change_event->{newResource}{campaignBudget};
  } elsif ($resource_type eq CAMPAIGN_CRITERION) {
    return $change_event->{oldResource}{campaignCriterion},
      $change_event->{newResource}{campaignCriterion};
  } elsif ($resource_type eq AD_GROUP_FEED) {
    return $change_event->{oldResource}{adGroupFeed},
      $change_event->{newResource}{adGroupFeed};
  } elsif ($resource_type eq CAMPAIGN_FEED) {
    return $change_event->{oldResource}{campaignFeed},
      $change_event->{newResource}{campaignFeed};
  } elsif ($resource_type eq FEED) {
    return $change_event->{oldResource}{feed},
      $change_event->{newResource}{feed};
  } elsif ($resource_type eq FEED_ITEM) {
    return $change_event->{oldResource}{feedItem},
      $change_event->{newResource}{feedItem};
  } else {
    print "Unknown change_resource_type $resource_type.\n";
  }
}
      

Keeping synchronized locally

If your goal is to get a current picture of your account and all its fields, you can use the change status to get a list of change resources and then query each of them to get its current state. However, if your goal is to get a complete picture of exact changes within a given window, use Change Event as outlined above.

Though changes made through the API or the web UI are recorded by Change Event service, there are some other ways changes can be made that are not. So Change Status service is still the best way to get a comprehensive view of what changes have been made in your account.