Sitecore how to show item's field in a datasource instead of item name

Question

In a templateItem I have following information for a field.

Name : Product type
field type : 'Droplink' 
DataSource : DataSource=/sitecore/content/Enumerations/Products/Product type/

When the content editor creates an item based on above template, for the field 'Product type' in the dropdown he will see the items under ../Product type. My question is for the items which are show in dropdown how to show some other field instead of item name

Answer 1

This functionality does not exist out of the box, although the code for the DropLink field looks like has code in there to be able to do this (take a look at the GetItemHeader() method in Sitecore.Shell.Applications.ContentEditor.LookupEx), I do not know how to utilize the parameter through the Content Editor though...

It's simple enough to create a custom field to achieve this though:

using Sitecore;
using Sitecore.Data.Items;
using Sitecore.Shell.Applications.ContentEditor;

namespace MyProject.Custom.Fields
{
    public class CustomDropLink : LookupEx
    {
        protected override string GetItemHeader(Item item)
        {
            if (string.IsNullOrEmpty(this.FieldName))
                this.FieldName = StringUtil.ExtractParameter("FieldName", this.Source).Trim();

            return base.GetItemHeader(item);
        }
    }
}

Then register your custom class in the core database under /sitecore/system/Field types/. You can do this by duplicating /sitecore/system/Field types/Link Types/Droplink and setting the following values:

Assembly: MyProject.Custom
Class: MyProject.Custom.Fields.CustomDropLink
Control: <set this to empty>

Then when you utilise this field set the Source of your field like so:

Datasource=/sitecore/content/path/to/items&FieldName=Title