Navigating DataSets Tutorial

Navigating DataSets

WellKnown files are first-class user objects. WellKnown files have a name,
which need not be unique, and which is assigned to the !WellKnownName property.

Virtually every application will define one or more types of WellKnown files. To
facilitate sharing between systems, the file name of a WellKnown file is usually
a system generated random string assured of being unique.

DataSet files are used to hold a collection of WellKnown files using the !DataSetItem property. The WellKnown files in a DataSet may be of more than one type, and may even be of types defined by more than one application. A WellKnown file may also be held by more than one DataSet. DataSet files can also be WellKnown, allowing the user to assemble DataSets into trees (or bushes). However, circular structures are not allowed. The root DataSet file is "Data".

WellKnownDirectory files are directories which hold a single type of
WellKnown file. The sh operation is defined on WellKnownDirectory files to list the directory content with the WellKnown names. (The dir command is particularly useless here, as the file names are difficult for a user to work
with.)

The sh operation defined on DataSets also lists its content with WellKnown names. Conversly, the shds operation defined on WellKnown files lists the WellKnown names of the DataSets holding the WellKnown file.

WellKnownDirectory files are found in the /WellKnownDirectories directory.
DataSets are found in the /WellKnownDirectories/DataSets. And the
"Data" DataSet can be found at /WellKnownDirectories/DataSets/Data.
(This DataSet does not have a generated file name--both its file name and
WellKnown name are "Data".)

tki> dir
1. !Dictionaries, A Directory
2. Applications, A Directory
3. Capabilities, A Directory
4. Descriptors, A Directory
5. Dictionaries, A Directory
6. Loaded, A Directory
7. Maps, A Directory
8. Operations, A Directory
9. Properties, A Directory
10. Text, A Directory
11. Transactions, A Directory
12. Users, A Directory
13. WellKnownDirectories, A Directory

tki> cd #13

tki> dir
1. DataSets, A directory containing WellKnown files.
2. Phonebook1Numbers, A directory containing WellKnown files.
3. Phonebook1People, A directory containing WellKnown files.
4. Relations1, A directory containing WellKnown files.
5. ToDo1, A directory containing WellKnown files.

tki> cd #1

tki> dir
1. Data, A DataSet file.
2. ILt0h4cNLqabB+cUEXtj415L, A DataSet file.
3. avT4K-tvnXx3F5n4Q-EzKF+4, A DataSet file.
4. m7WCILr6IXS34nBgZRHKUOSb, A DataSet file.
5. vgzxhd+jgrJT6QU2PDFmJht6, A DataSet file.

tki> sh
1. People
2. Phones
3. Phonebook
4. Relations
5. Data

tki> cd #1

tki> sh
1. Zikes, Sam
2. Smith, Joan
3. Smith, John

tki> shds
1. Phonebook

tki> cd #1

tki> sh
1. People
2. Phones

tki> shds
1. Data

tki>