This document discusses custom field types in SharePoint. Custom field types allow developers to define custom data structures, validation, and rendering for fields. They combine aspects of fields, web parts, validators, and event receivers. Some examples of when to use custom field types include storing multicolumn data or data related to an external system. The document reviews implementing custom field types including defining the type, properties, validation, and deployment. It also compares custom field types to other extensibility options like content types, web parts, and event receivers.

1. SharePoint Custom Field TypesEugene RosenfeldCTO, Black Blade Associates2-time SharePoint MVPerosenfeld@blackbladeinc.comwww.blackbladeinc.comthingsthatshouldbeeasy.blogspot.com

2. ContentsContentsCustom Field Types Defined

3. Business Cases

4. Custom Field Types and Alternate WSS Extensibility

5. Custom Field Types Implementation

6. DemoCustom Field Types DefinedOverviewCustom field types are Windows SharePoint Service’s mechanism for allowing developers to:

7. Define atomic data structures with custom data structures

8. Custom data validation

9. Custom rendering

10. Custom property storage and processing

11. These items are “what” custom field types can do

12. Custom field types can be thought of as a merging between fields, custom web parts, validators, and event receiversCustom Field Types DefinedCustom Field Type ScenariosCustom field types allow developers to interact with and extend the way in which Windows SharePoint Services organizes, collects, modifies, stores, and displays list item data:

13. Add a field that is based on a custom field type to a list

14. Edit a list field that is based on a custom field type

15. Show data stored in a custom field type instance in the list item display form

16. Show data stored in a custom field type instance in the list item edit form

17. Show data stored in a custom field type instance in the list item new form

18. Show data stored in a custom field type instance in the list view

19. These items describe “when” we would resort to custom field types.Custom Field Types DefinedCustom Data Structures Custom field types may define one or more field data components

20. SharePoint treats all field components as one, indivisible entity

21. SharePoint saves and loads all components of a custom field type as a single unit

22. Any custom data structure is fair game, as long as it is serializable as text

23. Why text, even for booleans, numbers, dates, etc?

24. All data is stored in SQL. Data is retrieved and modified using SQL statements. SQL statements are text, even for logically binary data.Custom Field Types DefinedCustom RenderingDevelopers can associate web controls to display field data to users

25. Think of field render controls as custom web parts that are always associated with all instances of the custom field type

26. Custom rendering controls may include:

27. Web custom controls

28. Client controls or HTML

29. JavaScript

30. AJAX

31. Images

32. Anything else that can render a MIME type that the client browser can interpretCustom Field Types DefinedCustom Field Type PropertiesCustom field types can define custom properties that instances of those field types can set

33. Custom field type properties are meant to allow users to modify the behavior of a custom field type instance