iOS Gmail API - Sample code to retrieve Gmail messages for a given label in Swift 4 / Xcode9

first question for me on stackoverflow.com so hopefully I am doing it correctly!

I currently have the following code (Xcode 9 / Swift 4) using the example provided in the Gmail API web site which works fine:

let query = GTLRGmailQuery_UsersMessagesList.query(withUserId: "me")
service.executeQuery(query,
                         delegate: self,
                         didFinish: #selector(displayResultWithTicket2(ticket:finishedWithObject:error:))

However instead of retrieving all emails for "me", I just want to retrieve the emails for a given label. Google has an example here in its API reference where one of the parameters can be a label but unfortunately I cannot find the equivalent Swift code. They "only" cover: Java, .Net, Php, Python and Javascript.

My question is about: how do you code this in Swift? The method above "GTLRGmailQuery_UsersMessagesList.query" only accepts a User Id.

Alternatively the example mentions the use of HTTP request and parameters (in particular "q"), can I use that in Swift and how?

Thanks!

Solution

Oh my, it was soooo simple! After the first line of code (let query...), you just need to call the properties of "query", e.g.

let query = GTLRGmailQuery_UsersMessagesList.query(withUserId: "me")
query.q = "is_unread"
service.executeQuery(query,
                         delegate: self,
                         didFinish: #selector(displayResultWithTicket2(ticket:finishedWithObject:error:))

Lots to learn for me! But hopefully that will be useful to someone!