5.15 General-Purpose Fields ↑

5.15.6 Lookback

The word lookback can be used as a field type, but is not intended to be used as a field label.

It is intended to be used in conjunction with a Lookup field in another Collection.

For example, if a Collection stored in a folder titled quotes had a lookup field to another Collection titled authors, then the authors collection could have a lookback field pointing back to the quotes collection. This lookback field would then display all of the quotes attributed to each author.

Both Collections must be identifiable via a Collection ID.

A lookback field can only be added to a Collection by editing the Collection Template file.

Here is an example of how a lookback field might be specified.

Author Quotes: <lookback: quotes> 

The identifier for the Collection to be referenced must be specified following the colon. In the example above, ‘quotes’ is the identifier for the second Collection.

Note that a lookback field is similar to a Back Links field, with the difference that Backlinks are used for Wiki Links Between Collections, while lookbacks are used for lookups within Collections.

One must be mindful of Disk Access Permissions when using a field with type lookback. This can probably best be handled by putting the second Collection alongside of the first, within the same parent folder. You can then use the Open Project Folder command to first open the parent, and then from there open either of the Collections.

Note that lookback values are calculated dynamically when a Collection is opened, and so no lookback values are stored within a Note’s disk file.

When viewing a lookback field on the Display tab, the lookback values will be formatted as links, using Notenik’s own Custom URL Scheme.