Validation Settings

If this link is clicked, the library administrator will be taken to the Validation Settings page, as shown in Figure 20.16, where she can specify a formula to validate the data when new items are saved to the list or are edited. User message text can be entered as well, so the end user is informed of the criteria that weren’t met successfully. In this example, the formula is as follows:

=ProjectNumber>5000

Figure 20.16. Validation Settings page with sample formula.

This translates to: The value entered in the ProjectNumber column must exceed 5000 to provide a value of True.

If the results of the equation entered do not equal a value of True, the user will get an error, which will be in one of two formats, depending on whether the user is trying to upload a document and enter incorrect/invalid metadata or if the user is trying to edit metadata for an existing document in the library. If the user is uploading a document and enters incorrect metadata, an error screen will display that says “List data validation failed” but will not display the user message text. If the user is editing metadata for a document already in the library, she will see the actual message text entered. In this example, the message is “You must enter a number greater than 5000 to pass validation.”

This feature is examined in more detail in Chapter 22.