What's the correct/agreed way to partial update REST API in Golang

Let's say we have a struct

type Person struct {
	ID                          string `json:"id"`
	Name                        string `json:"name"`
	DOB                         string `json:"dob"` 
	Status                      string `json:"status"`     // enabled/disabled
	Address                     string `json:"address"`
	DataRetentionPeriod         uint32 `json:"dataRetentionPeriod"`
	PrimaryContact              `json:"primaryContact"`
}

type PrimaryContact struct {
	Name  string `json:"name"`
	Phone string `json:"phone"`
	Email string `json:"email"`
}

We want to be able to partial update this struct as we see fit. For example, we want to only change his Address or DataRetentionPeriod or PrimaryContact. We are using DynamoDb so the end product needs to be map[string]interface{} when sending the updates.

What is the best/correct way of doing this in Go?

These are the following approaches we have:

1) Send a new complete body every time. This will resolve the issue but the problem is the client needs to send more data than necessary over the network. So we want to avoid this.

2) We can turn the original struct into pointers and then check the nil values using reflect and then transform it into map[string] interface to send to the SDK

3) Use a package like structs to build a new struct that's coming from the API with only the fields required

4) Unmarshal the body into a map[string]json.RawMessage and then map over the items and verify the correct/required fields and then transform it into map[string]interface

A few others but none of them feel clean.

Please advise on "best" way to do partial updates using Golang for REST APIs.

Thank you.

There are many approaches as you noted.

gRPC uses an approach that works well for my use cases. Basically a PATCH where the request contains two structs your data struct and an update mask ([]string), the mask specifies what will be updated.

consider this

type Person struct {
    ID                          string `json:"id"`
    Name                        string `json:"name"`
    DOB                         string `json:"dob"` 
    Status                      string `json:"status"`     // enabled/disabled
    Address                     string `json:"address"`
    DataRetentionPeriod         uint32 `json:"dataRetentionPeriod"`
    PrimaryContact              `json:"primaryContact"`
}

type PrimaryContact struct {
    Name  string `json:"name"`
    Phone string `json:"phone"`
    Email string `json:"email"`
}

// PersonRequest would be accepted via http PATCH method in you service
// the `updateMask` if populated would specify the client's desired changes
// an example of Request might look like this
//
// myUpdateRequest := PersonRequest{
//     Person{Name:"joe",DOB:"01-01-1970",PrimaryContact: PrimaryContact{Phone: "+12223334444"}},
//     UpdateMask: []string{"name", "dob", "primaryContact.phone"},
// }
//
Type PersonRequest struct {
    Person     Person   `json:"person"`
    UpdateMask []string `json:"updateMask"`
}

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