Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) - Manual (Page 583)

C H A P T E R 1 5
Filing
Using the Filing Service 15-17
perform any other actions that are appropriate, such as redrawing views affected by
the change in filing filter.
The symbol passed as the sole argument to your NewFilingFilter method
specifies which of the storesFilter or labelsFilter slots changed in value.
This argument does not specify the slot’s new value, however. Your
NewFilingFilter method must use the current value of the specified slot to
retrieve those soup entries that fall into the new filing category.
The following code example shows the implementation of a typical
NewFilingFilter method, which queries the application soup for the entries
that match the current filing category and then redraws views affected by the
change in filing category.
NewFilingFilter: func(newFilterPath)
begin
// first figure out if query should be done on
// a union soup or on a specific store soup
// this is to make filter by store more efficient
local querySoup := GetUnionSoupAlways(kSoupName) ;
if storesFilter and storesFilter:IsValid() then
querySoup := querySoup:GetMember(storesFilter) ;
// now construct the query based on the labelsFilter
// and set my application cursor (called myCursor)
// to the new query
// the default is to show all items, i.e.,
// labelsFilter is '_all
local theQuery := nil ;
if NOT labelsFilter then
// labelsFilter is NIL, so show only those entries
// that do not have a valid tag in the labels
// slot
theQuery := {none: GetFolderList(appSymbol, nil)};
else if labelsFilter <> '_all then
// labelsFilter is some specific folder
theQuery := {all: labelsFilter} ;
myCursor := querySoup:Query(theQuery) ;