CSOM: fetching items using ViewFields and non-default properties

Question

I'm trying to get a particular set of columns for items in a list, as well as RoleAssignments which is a non-default property.

Assuming my CAML, where I define my ViewFields, is in a variable CAMLtemplate, I can get the desired columns:

clientContext.Load(CAMLtemplate);
clientContext.ExecuteQuery();

However when I add the additional properties, it seems I'm no longer getting the columns I've specified in my CAML:

clientContext.Load(CAMLtemplate, 
    iCol => iCol.Include(
                 item => item.RoleAssignments,
                 item => item.RoleAssignments.Include(
                                              ra => ra.Member.LoginName,
                                              ra => ra.RoleDefinitionBindings)));
clientContext.ExecuteQuery();

...I get an error when trying to work with a column I've requested in my CAML, like The property or field has not been initialized. It has not been requested or the request has not been executed. It may need to be explicitly requested.

This seems to suggest that I either need to explicitly request every column in my iCol.Include (seems crazy, there are lots of columns, and why bother with the CAML ViewFields if this is the case?), or do something else. How can I simply get the columns I want, as well as the additional property I want?

Answer 1

It turns out that by putting my two calls to the Load method one after the other, I could retrieve the columns and then the further attributes. I still don't understand why this can't be done in a single call, but this answer gave me the clue I needed. This works:

clientContext.Load(CAMLtemplate);
clientContext.Load(CAMLtemplate, 
     iCol => iCol.Include(
                 item => item.RoleAssignments,
                 item => item.RoleAssignments.Include(
                                          ra => ra.Member.LoginName,
                                          ra => ra.RoleDefinitionBindings)));
clientContext.ExecuteQuery();

Answer 2

You are getting this error because you are using the property of the object which is not yet initialized. So to initialize this just write

clientContext.ExecuteQuery();

after the line:

clientContext.Load(CAMLtemplate);

Please see below example

using System;
using Microsoft.SharePoint.Client;
using SP = Microsoft.SharePoint.Client;

namespace Microsoft.SDK.SharePointServices.Samples
{
    class RetrieveListItems
    {
        static void Main()
        {
            string siteUrl = "http://MyServer/sites/MySiteCollection";

            ClientContext clientContext = new ClientContext(siteUrl);
            SP.List oList = clientContext.Web.Lists.GetByTitle("Announcements");

            CamlQuery camlQuery = new CamlQuery();
            camlQuery.ViewXml = "<View><Query><Where><Geq><FieldRef Name='ID'/>" +
                "<Value Type='Number'>10</Value></Geq></Where></Query><RowLimit>100</RowLimit></View>";
            ListItemCollection collListItem = oList.GetItems(camlQuery);

            clientContext.Load(collListItem);

            clientContext.ExecuteQuery();

            foreach (ListItem oListItem in collListItem)
            {
                Console.WriteLine("ID: {0} \nTitle: {1} \nBody: {2}", oListItem.Id, oListItem["Title"], oListItem["Body"]);
            }
        }
    }
}

For more clarification to load fields, Please see below links.

Syntax for including fields dynamically in CSOM query?

How to include custom fields in clientContext.load()?