How to cache the Driving Range 3D Model¶

When issuing a GET request to download the Driving Range 3D model, the response headers will contain an Etag header, which identifies the version of the 3D model that is installed on the server. If a new model is uploaded on the server, the ETag value will change. Therefore, it can be used in order to conditionally retrieve the 3D model resource, only if it has changed since the last time the client has downloaded it.

The first time the client issues a GET request, it' s going to download the full 3D model locally and remember the ETag value. The next time, the client will issue a conditional GET including the additional header If-None-Match containing the value of the Etag that it had previously saved:

First request:

GET {MODEL-DOWNLOAD-URI}
Host: localsite.trackmanrange.com

Response:

200 OK
ETag: "1b6461003ce1cb46638a206e647b02e5"

Second request:

GET {MODEL-DOWNLOAD-URI}
Host: localsite.trackmanrange.com
If-None-Match: "1b6461003ce1cb46638a206e647b02e5"

If the model hasn't changed, the server is going to respond with the status code 304 Not Modified. Otherwise the downloading of the model is going to proceed as usual.