Hands-On RESTful Web Services with Go - Second Edition

Nested fields

We can also use a message as a type of another message. It is similar to a map data structure. It is analogous to nested JSON.

For example, take a look at the following JSON code:

{  "site": {      "url": "https://example.org",      "latency": "5ms",      "proxies": [        {"url": "https://example-proxy-1.org", "latency": "6ms"},        {"url": "https://example-proxy-2.org", "latency": "4ms"}      ]  }}

The preceding JSON contains information about a site that has a list of proxies. Each proxy is a map itself and contains details such as url and latency.

How can we model the same thing in protobufs? We can do this using the nested messages, as shown in the following code:

message Site { string url = 1; int latency = 2; repeated Proxy proxies = 3;}message Proxy ...