Assign a user list to a multi user picker custom field (number of user undefined)

Question

I want to assign a user list to a multi user picker custom field
The size and content of the list is undefined
/!\ The problem is that the value of the custom field is overwritten and not added at each iteration
So I want the list of all my users in my custom field without knowing the content and the size of the list

customfield_10226 is my custom field multi user picker

listUser.each{ user ->
def update = put('/rest/api/2/issue/' + issue.key)
.header('Content-Type', 'application/json')
.body([
fields:[
customfield_10226:[[accountId : user]]
]
])
.asString()
}

unknown · Accepted Answer

Hello @Aymeric Goujon

This question gets asked regularly. It's not possible to insert / add one or more new values somewhere into a set of existing values in a user picker custom field. That's not how the REST API works.

You need to:

* GET the current set of values from the field (usually into an array in your code)
* In your code, add the new value(s) in the position(s) you want in the array
* PUT / POST the new values into the field, in the order you have them in the array, to overwrite the old set of values.