@injectGeneratedUUID Directive

When creating new object in a database, it's common to use an incremental number as the primary key. However, sometimes it's preferred to generated unique IDs instead of letting the database decide on an id.

To solve this problem, a lot of developers reach to UUID, a method of creating unique IDs. Some systems, like PostgreSQL support UUID natively, other have to rely on a service to generate the UUIDs for them.

To make using UUIDs as convenient in WunderGraph as possible, we've created the @injectGeneratedUUID directive.

Simply attach it to a variable definition and WunderGraph automatically injects a UUID into the string, all server-side, so the client cannot temper it.

Additionally, by attaching the @injectGeneratedUUID directive to a variable definition, the variable is removed from the input variables, disallowing the user to use it.

Let's look at an example for a user sign up:

mutation ($email: String!, $name: String!, $id: String! @injectGeneratedUUID) {
  createOneuser(data: { id: $id, email: $email, name: $name }) {
    id
    name
    email
  }
}

The user is allowed to enter their email and name while the WunderGraph Server injects the $id variable. This works independently of the upstream. You could use this with a database or API.

@injectGeneratedUUID accepts an optional on: argument that might be used to inject a value into an specific field. Given the following type:

input createUserInput {
  id: String!
  email: String!
  name: String!
}

We can use @injectGeneratedUUID to set the value of id using:

mutation ($input: createUserInput! @injectGeneratedUUID(on: "id")) {
  users_Create($input) {
    id
    email
    name
  }
}

@injectGeneratedUUID can be used multiple times on the same operation, injecting data into different fields. Additionally, @injectGeneratedUUID can be combined with other directives for injecting or manipulating data like @fromClaim, @injectCurrentDateTime, @injectEnvironmentVariable and @jsonSchema.