Optimistic update: Error at path "<query_with_pagination>.nextToken": missingValue

[richienko]

The query with argument within optimistic update closure will fail with "missingValue" message.
The query is paginated.

Version of AppSync:
2.6.18

Message I'm getting:
Error at path "listJobsByCustomer.nextToken": missingValue

Mutation:
updateJob(input: UpdateJobInput!): Job

Query called in optimistic update closure:
listJobsByCustomer(customerId: String, first: Int, after: String): JobConnection

JobConnection:

type JobConnection {
	items: [Job]
	nextToken: String
}

Code:

let mutation = UpdateJobMutation(input: input)

appSyncClient?.perform(mutation: mutation, optimisticUpdate: { (transaction) in
	do {
		// Update our normalized local store immediately for a responsive UI
		let query = ListJobsByCustomerQuery(customerId: "customerId", limit: 1)
		try transaction?.update(query: query) {
			(data: inout ListJobsByCustomerQuery.Data) in

			for i in 0..<(data.listJobsByCustomer?.items)!.count {
				if data.listJobsByCustomer?.items?[i]?.id == input.id {
					data.listJobsByCustomer?.items?[i]?.status = input.status!
				}
			}
		}
	} catch let exception {
		print("UpdateJobMutation Error updating the cache with optimistic response: \(exception.localizedDescription)")
	}
}) { (result, error) in
	if let error = error as? AWSAppSyncClientError {
		print("Error occurred: \(error.localizedDescription )")
		return
	}
	
	if let res = result {
		print("UpdateJobInfo result: \(res)")
	}
	
	self.handleNetworkStateOnResult(online: true)
}

[wir349]

I'm having a similar issue, except I'm not using pagination.

[koingruc]

Is this bug is fixed in Release v2.6.18 ? Thanks

[richienko]

@koingruc no, it's not fixed, I'm using 2.6.18 and it's bugged

[koingruc]

@richienko Thank you for the information. Hope it is fixed soon

[ghost]

Same issue. Simply trying to implement a basic mutation with the sample code provided on the official doc page, yet getting "missingValue" from transaction?.update.

[koingdev]

For those who have problem with optimistic UI missing value. I've found one trick to temporary solve the issue by passing parameter using Custom Request Header from client app.
Before, your query would look like this allDiaries(author: String): [Diary]
Just change it to => allDiaries: [Diary]
So your request mapping would look like below:

{
    "version" : "2017-02-28",
    "operation" : "Scan",
    "filter" : {
        "expression" : "author = :author",
        "expressionValues" : {
            ":author" : { "S" : "$context.request.headers.author" }
        }
    }
}

Reference: https://stackoverflow.com/questions/51932849/how-to-pass-aws-appsync-custom-request-header-in-ios-client/51950574#51950574
Hope it is useful! Goodluck :)

[hemant236]

Any update on the issue, Is it fixed in latest 2.6.21

[koingruc]

@hemant236 It is not yet fixed. You can check the changelog.
https://github.com/awslabs/aws-mobile-appsync-sdk-ios/blob/master/CHANGELOG.md
If you have this issue, you can try my solution :) I solved it using Request Header instead of Argument

[hemant236]

@koingruc Is there any other framework/class that I need to import for using CognitoAuthProvider() and CognitoUserPoolManager?
Use of unresolved identifier 'CognitoUserPoolManager'

[rohandubal]

This is now fixed with SDK Version 2.6.22