DATA - Handle

Reference

Handle is a built-in field for all Instances as a companion field to keyname primary keys. Handles are automatically computed fields to derive an URI friendly primary key for Instances

keyname must be a primary key, that is, must have a unique value accross all instances of a DataClass.

Sometimes, you may want to use an external primary key from an other system to maintain synchronization ; or may wan’t a nice human friendly keyname for display reason. If your keyname - although unique - does have special characters (accent, white spaces, comma, …) it’is not suitable for Web URIs and REST APIs.

When you define a DataClass, you have to choose the method to compoute the handle field. By default, the keyname field is used.

Handle methods

handle_method
    # keyname
    # uuid
    # md5
    # external