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FrameDirty is Deep, But Can Be Fooled (8/19/94)

Q: Does the global function FrameDirty see changes to nested frames?

A: Yes. However, FrameDirty is fooled by changes to bytes within binary objects. Since strings are implemented as binary objects, this means that FrameDirty will not see changes to individual characters in a string. Since clParagraphViews try (as much as possible) to work by manipulating the characters in the string rather than by creating a new string, this means that FrameDirty can be easily fooled by normal editing of string data.

Here is an NTK Inspector-based example of the problem:

s := GetStores()[0]:CreateSoup("Test:DTS", []);
e := s:Add({slot: 'value, string: "A test entry", nested: {slot: 'notherValue}})
#4410B69  {slot: value, 
           String: "A test entry", 
           nested: {slot: notherValue}, 
           _uniqueID: 0}
FrameDirty(e)
#2        NIL

e.string[0] := $a; // modify the string w/out changing its reference
FrameDirty(e)
#2        NIL

EntryChange(e);
e.string := "A new string";    // change the string reference
FrameDirty(e)
#1A       TRUE

EntryChange(e);
e.nested.slot := 'newValue;    // nested change, FrameDirty is deep.
FrameDirty(e)
#1A       TRUE

s:RemoveFromStore()    // cleanup.