Serial Generator

This module provides api which generates thread safe unique serial number for a given key.

Q) How is this different from nid?
A) nid serial is unique across all nodes created in the system. Serial Generator generates a different sequence based on key provided by user.

Example: If you have 10 different exams and multiple submissions for each exam, every exam's submissions have separate sequence (usually starts with 1), exam name being the key.

Q) How is it different from other modules that generate serial based on Content Type?
A) Those modules are based on content type. Serial Generator is based on key. Key can be anything

Ex:
"node" as key provides node level serial across content types
content type name provides as key provides content type level serial
nid of node as serial provides individual node item level serial (every node has its own sequence). This is useful in case several other nodes are referring a node -- like submissions referring an exam)

Q) How do I use it in UI?
A) This module is intended to be used as API in other modules and not a end user module by itself.