Get a value included from a lookup column using the JavaScript Client Object Model

Question

Related: How to retrieve a ListItem using the Javascript Client Object Model?

In my previous question I was able to successfully retrieve a basic value from a list item. My problem is that I am now trying to retrieve a value from a LookUp column get_item no longer seems to work.

When I do an alert, I get [object Object] instead of the value that is in there.

Code I am using:

function onSuccess(sender, args) {
        alert(oDeptItem.get_item('Department'));
        $('#contact').html(oDeptItem.get_item('Department'));
    }

Should I be using something besides get_item to values from LookUp columns?

Answer 1

Looks like I just needed to add the get_lookupValue() function after my get_item call:

alert(oDeptItem.get_item('Department').get_lookupValue());

Hope this helps someone...

Answer 2

For those not using JSOM and need a solution using REST + JSON, this can be done using the REST API and OData. For example if the list in questions is Employee with a Department Lookup field. We can send a REST request with this format:

_api/web/lists/getbytitle('employee')/items?$select=Department/Name,DepartmentId,Name,Id&$expand=Department

Note the OData request parameters $select and $expand (this is needed to get other fields from the lookup list). This request should return:

Employee id and name Department id and name

More information can be found here:

http://www.ozkary.com/2015/10/sharepoint-2013-api-odata-for-lookup-fields.html

hope it helps.

Answer 3

Using Abe Misseler answer:

var oItem ='';
function retrieveWebSite() {
    SP.SOD.executeFunc('sp.js', 'SP.ClientContext', function(){
        var clientContext = new SP.ClientContext.get_current();
        this.oWebsite = clientContext.get_web();
        clientContext.load(this.oWebsite);

        var lstObject = oWebsite.get_lists().getByTitle('Listname');
        oItem = lstObject.getItemById(5);
        clientContext.load(oItem);

        clientContext.executeQueryAsync(
            Function.createDelegate(this, this.onQuerySucceeded), 
            Function.createDelegate(this, this.onQueryFailed)       
        );
    });
}

function onQuerySucceeded(sender, args) {
    var look  = oItem.get_item('LookupColumnName').get_lookupValue();
    var title = oItem.get_item('Title');
    var id = oItem.get_id();
    alert("Loook up column value: "+look);
    alert("Title column: "+title);
    alert("Id column value: "+id);
}

function onQueryFailed(sender, args) {
    alert('Request failed. ' + args.get_message() + 
        '\n' + args.get_stackTrace());
}