In-flight checking with hooks and callbacks

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

Hooks and callbacks allow you to run your code at various times and in various unpredictable circumstances while executing a job. The pagedevice hooks described in Hooks are one set of examples, comprising both Level 2 PostScript features and RIP extensions.

There is a further set of circumstances for which you can configure the RIP to call out to your PostScript routines. These RIP extensions are known as miscellaneous hooks and are configured with the setmischooks operator in internaldict . A currentmischooks operator, also in internaldict, returns the current procedures that have been installed, together with associated configuration data. Each procedure is a callback procedure.

All objects in the dictionary returned by currentmischooks for callback procedures that have not been installed are null objects. All configuration values are set to -1.0 initially.

Both installed procedures and their configuration data are subject to use of save and restore. Most of the initial set of procedures are designed for use as in-flight checking.