Specify an Initial value for create (like .default() but never overrided by user values)

Describe the feature you'd like to request

Given the following schema:


const schema = a.schema({
  Todo: a.model({
    updatesCount: a.number().default(0),
    content: a.string(),
    completed: a.boolean().default(false),
  })
  .authorization(allow => [allow.publicApiKey()]),
});

I would like to be able to specify an initial value for specific fields. I want Todo.updatesCount to always have the initial value of 0 and Todo.completed to have an initial value of false.

Describe the solution you'd like

I would like to be able to set the initial value with .initial(val: any).


const schema = a.schema({
  Todo: a.model({
    updatesCount: a.number().initial(0),
    content: a.string(),
    completed: a.boolean().initial(false).default(false),
  })
  .authorization(allow => [allow.publicApiKey()]),
});

Describe alternatives you've considered

An alternative is to set the default value and then define a restrictive input createTodoInput that does not contain the value. Since the user cannot submit the value the default value is always used. This is subject to the user's permission to set the value.


input CreateTodoInput {
    ## updatesCount: number,
    content: a.string(),
    ## completed: bool,
}

Additional context

The values for .default() are set in the init pipeline resolver:

## Resolver: MutationcreateTodoinit0Function

## [Start] Initialization default values. **
$util.qr($ctx.stash.put("defaultValues", $util.defaultIfNull($ctx.stash.defaultValues, {})))
$util.qr($ctx.stash.defaultValues.put("id", $util.autoId()))
#set( $createdAt = $util.time.nowISO8601() )
$util.qr($ctx.stash.defaultValues.put("createdAt", $createdAt))
$util.qr($ctx.stash.defaultValues.put("updatedAt", $createdAt))
$util.toJson({
  "version": "2018-05-29",
  "payload": {}
})
## [End] Initialization default values. **

...which are then superceded by user values when merged in:

## Resolver: MutationCreateTodoDataResolverFn

## Set the default values to put request **
#set( $mergedValues = $util.defaultIfNull($ctx.stash.defaultValues, {}) )
## copy the values from input **
$util.qr($mergedValues.putAll($util.defaultIfNull($args.input, {})))

# ...

A simple implementation for .initial() could store values as $ctx.stash.initialValues and merge them in on top of user values. However, this approach would be subject to the user's authorization allowing them to set these values.

A more complete implementation would set these values separately from the user submitted values. This would allow initial values to be set even if the user does not have write permissions on those fields.

Is this something that you'd be interested in working on?

[ ] 👋 I may be able to implement this feature request

Would this feature include a breaking change?

[ ] ⚠️ This feature might incur a breaking change

aws-amplify / amplify-category-api