I'm using the SharePoint Client Object Model to query lists in Sharepoint and need to create the Linq queries dynamically in a helper assembly.
How do I create the following from a list<string> of column names containing "Id","Title","LinkFileName","Status" ?
context.Load(listItems, items => items.Include(
item => item["Id"],
item => item["Title"],
item => item["LinkFilename"],
item => item["Status"]
));
a BIG thank you to Manvir for his post that solved my problem:
http://www.manvir.net/invalidqueryexpressionexception-the-query-expression-is-not-supported/
Replace the ClientContext.Load with ClientContext.LoadQuery that does support runtime-built expressions.
private static Expression<Func<ListItem, object>>[] CreateListItemLoadExpressions(List<string> viewFields)
{
List<Expression<Func<ListItem, object>>> expressions = new List<Expression<Func<ListItem, object>>>();
foreach (string viewFieldEntry in viewFields)
{
string fieldInternalName = viewFieldEntry;
Expression<Func<ListItem, object>> retrieveFieldDataExpression = listItem => listItem[fieldInternalName];
expressions.Add(retrieveFieldDataExpression);
}
return expressions.ToArray();
}
