devops-rest APi - $expand not working for "Work Items - Get Work Items Batch"

Question

I want to access some data from selected work items.
Below is my working code.

function postApiData(ApiUrl, responseBody, token) {
            var res = '';
            $.ajax({
                type: 'POST',
                async: false,
                url: ApiUrl,
                contentType: 'application/json',
                data: JSON.stringify(responseBody),
                cache: false,
                dataType: 'json',
                beforeSend: function (xhr) {
                    xhr.setRequestHeader("Authorization", "Basic " + btoa("" + ":" + _token));
                },
            }).done(function (data) {
                res = data;
            });
        return res;
    };

 var d = {
                    "ids": itemlist,
                    "fields": ["System.Id", "System.WorkItemType", "System.Title", "System.AssignedTo", "System.State", "System.Tags", "cust.PID", "cust.Product", "cust.ReleasedToProduction"]
                };
                var itemdata = postApiData('https://dev.azure.com/COMP/products/_apis/wit/workitemsbatch?$expand=relations&api-version=5.1', d, '');

However, $expand is not working here to get relations. query gives the result and always ignores $expand.

I have also tried to pass $expand in request body, but it is also not working. Can anyone please guide here?

Answer 1

That's because the expand parameter can not be used with the fields parameter if the expand value is relations.

You could execute this api with your request body in Postman. You will get the clearly message that why you can not apply it.

---

To use your API, if you specify the fields in the request body, then expand should not be used any more, and vice versa. This is as designed, and it has been hardcoded into our scripts. We do not allow another $expand value if it is not the None or Links.

For the 5 values of $expand(None, Relations, Fields, Links, All), only None and Links can work with fields successfully in API. This is a universal rule which apply to all APIs, including this one.

---

Also, please use $expand=Relations in request body instead of in URI which shown as the document described. Here if you use it in URI, it will not be used by server script since the method that this API called does not has this parameter. Another API which can use $expand in the URI (As normal, we would mention and show whether it can be used in URI in document), the corresponding scripts have parameters can access these value which passed by URI.

So, here please use $expand=Relations in request body, then you would get the result with all fields and its all relations.