How to Control Sort Order in NewtApp

One of the Newton 2.x OS Q&As
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This document was exported on 7/23/97.

How to Control Sort Order in NewtApp (5/10/96)

Q: While a NewtApp application is running, can I change the order in which soup items appear?

A: Yes, the key to changing the sort order is to modify the query spec in the allSoups frame, and then cause the application to refresh. The cursor that controls the sort order for the layout is built from the masterSoupSlot slot. Both the default and the overview layouts have a masterSoupSlot which points back to the relevant allSoups slot in the app base view.

Here are the basic steps:

1) Ensure newtAppBase.allSoups & newtAppBase.allSoups.mySoup are writeable. (Since the frames reside in the package, they are in protected memory.)
2) Modify the query spec to the new sort order.
3) Now send newtAppBase.allSoups.mySoup:SetupCursor() to create a new cursor using the new query spec.
4) Then do a newtAppBase:RedoChildren() to display the items in the new sort order.
The code would look something like:
      if IsReadOnly (newtAppBase.allSoups) then
        newtAppBase.allSoups := {_proto: newtAppBase.allSoups};
   if IsReadOnly (newtAppBase.allSoups.mySoup) then
        newtAppBase.allSoups.mySoup :={
            _proto: newtAppBase.allSoups.mySoup};
        newtAppBase.allSoups.mySoup.soupQuery := 
            {indexpath: newKey};            // new sort order!
        newtAppBase.allSoups.mySoup:SetupCursor();
        newtAppBase:RedoChildren();