The Head or Tail Connection Reference Attribute
- Last UpdatedNov 17, 2025
- 1 minute read
Keywords:
HREF TREF
Description:
These attributes hold the name of the element to which the Branch or Hanger is connected. They are usually set automatically as a result of a CONNECT PH (or PT) command, but they may also be set explicitly. When they are set, the corresponding attribute (CREF, HREF or TREF) of the item connected to is reset so as to point back to the Branch or Hanger.
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Examples: |
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TREF /PIPE2 HEAD |
Sets TREF of current element to point to Head of /PIPE2 and setsHREF of /PIPE2 to point back to the current element. |
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HREF NULREF |
Unsets HREF; that means, disconnects Head from any other element. |
Command Syntax:
>--+-- HRef --.
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‘-- TRef --+-- <gid> --+-- HEAD --.
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| |-- TAIL --|
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| ‘----------+
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‘-- NULREF --------------+-->
Querying:
>-- Query --+-- CE ------.
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|-- HEAd ----|
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|-- BRANch --|
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‘-- TAIl ----+-->
>-- Query --+-- HREF --.
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‘-- TREF --+-->