Hide IDs

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Hide is a simple package to provide an ID type that is marshalled to/from a hash string. This prevents sending technical IDs to clients and converts them on the API layer. Hide uses hashids as its default hash function. But you can provide your own by implementing the Hash interface and configure it using hide.UseHash.

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go get github.com/emvi/hide


Consider the following struct:

type User struct {
    Id       int64  `json:"id"`
    Username string `json:"username"`

When marshalling this struct to JSON, the ID will be represented by a number:

    "id": 123,
    "username": "foobar"

In this case you expose the technical user ID to your clients. By changing the type of the ID, you get a better result:

type User struct {
    Id       hide.ID `json:"id"`
    Username string  `json:"username"`

Notice that the int64 ID got replaced by the hide.ID, which internally is represented as an int64 as well, but implements the marshal interface. This allows you to cast between them and use hide.ID as a replacement. The resulting JSON changes to the following:

  "id": "beJarVNaQM",
  "username": "foobar"

If you send the new ID (which is a string now) back to the server and unmarshal it into the hide.ID type, you’ll get the original technical ID back. It’s also worth mentioning that a value of 0 is translated to null when an ID is marshalled to JSON or stored in database.

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