FileMaker Pro 9: The Missing Manual

Containers in Calculations

Although it isn’t a typical calculation data type, you can do a few interesting things with container fields in calculations. You don’t have the same vast options you do with other types. It would be great if you could subtract Cousin Clem.jpg from Family Reunion.jpg to get the scoundrel out of the picture, but alas, the technology’s not quite there yet. Nevertheless, FileMaker doesn’t leave containers entirely out in the cold when it comes to calculations.

Calculations with Pictures, Sounds, Movies, and Files

When you create a calculation field, you can set its result type to Container. You can’t create container data in a calculation, but you can refer to other container fields. When you do, the picture, sound, movie, or file in the referenced container field shows in the new calculation field.

You can, for example, make a calculation field that shows the contents of one container field when you’re in Browse mode and another in Preview mode. This field lets you use low-resolution images when you view on the screen, and higher resolutions when you view in print. (You’ll learn to do that in the next chapter, when you learn about calculations with that kind of decision-making ability.)

You may also want to use container fields in a calculated replace. Suppose you have a found set of 30 records that don’t have a low-resolution image. You have to have something in that field, so you decide to take the hi-resolution image for those few records and plunk them down ...