Google Routes api X-Goog-FieldMask is not working

Issue: Google Routes API X-Goog-FieldMask not functioning correctly.

Background: The Google Routes API allows developers to calculate directions between locations. When making requests to the API, developers can specify a field mask using the X-Goog-FieldMask header. This field mask restricts the fields in the response to only those specified in the mask. However, some users have encountered an issue where the X-Goog-FieldMask header is not working as expected.

Solution 1: Ensure Proper Usage of OptimizeWaypointOrder and Routing Preference

• To use the optimizeWaypointOrder flag, you must set routingPreference to TRAFFIC_AWARE_OPTIMAL.
• Conversely, using TRAFFIC_UNAWARE will result in an error if optimizeWaypointOrder is set to true.

Solution 2: Verify Field Inclusion

• Some fields, such as polylineQuality and polylineEncoding, may cause issues when included in the X-Goog-FieldMask header.
• Try removing these fields from your request and check if the issue persists.

Solution 3: Include Optimized Intermediate Waypoint Index

• When using optimizeWaypointOrder, the routes.optimized_intermediate_waypoint_index field must also be included in the X-Goog-FieldMask header.

Additional Information:

• For more information on using the Google Routes API, refer to the official documentation.
• If you continue to encounter issues, you can seek assistance on Stack Overflow or other relevant forums.

Conclusion: When using the Google Routes API, it is crucial to ensure that the X-Goog-FieldMask header is utilized correctly. By following the solutions mentioned above, you can resolve common issues related to the X-Goog-FieldMask header and retrieve the desired fields in the API response.