StreamLink and Liberator can use a directory based hierarchical name space for data items such as records. Directories can be used as a means of organising information into groups and hierarchies.
For example, all Foreign Exchange instruments may be grouped under the directory
- "/" is the root directory
- "FX" (Foreign Exchange) is a directory underneath the root
All the FX instruments would be grouped underneath
/FX, and the subject that identifies an instrument includes the directory path.
The "/" delimiter is used to segregate levels of the directory hierarchy
For example, the FX instrument with symbol
EURUSD (Euros to US Dollars) has the subject:
A client can subscribe to a directory, and StreamLink then informs the client when items are created or deleted within that directory. When you subscribe to a directory you don't get an automatic subscription to the items in the directory; you have to explicitly subscribe to them as required.