Template field type - Control

Question

I have created a custom field type and it's working good.

Here is the screenshot of how its looks in core database. All i filled in for template field type Template is Assembly and Class fields.

Here is the screenshot of sitecore's default date field type.

Like you see the difference, i am not using "Control" field for my custom field type and sitecore default field is not using Assembly and Class fields.

So, my questions are

• what's the use of "Control" Field?
• How sitecore default date field working with out "Assembly" and "Class" fields?

Answer 1

In Sitecore configuration you can find <controlSources> section. It contains all the namespaces Sitecore parses when it looks for content:ClassName in a field definition (like Date in your example).

That's why Sitecore finds Sitecore.Web.UI.WebControls.Date class and uses it for the DateTime field.

One good example of how this can be extended is in Sitecore.Buckets.config:

<controlSources>
  <source mode="on" prefix="contentExtension" namespace="Sitecore.Buckets.FieldTypes" assembly="Sitecore.Buckets" />
  <source mode="on" namespace="Sitecore.Buckets.Controls" assembly="Sitecore.Buckets"/>
</controlSources>

prefix="contentExtension" part says that field definition will have another prefix instead of the default content. So if you check Multlilist with Search field, you will see there contentExtension:BucketList value of the Control field.