Bug 8077 - add "empty" EL operator
Summary: add "empty" EL operator
Alias: None
Product: Taglibs
Classification: Unclassified
Component: Standard Taglib (show other bugs)
Version: unspecified
Hardware: All All
: P3 normal (vote)
Target Milestone: ---
Assignee: Tomcat Developers Mailing List
Depends on:
Reported: 2002-04-14 23:11 UTC by Nathan Abramson
Modified: 2004-11-16 19:05 UTC (History)
0 users


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Description Nathan Abramson 2002-04-14 23:11:13 UTC
Add "empty A" operator with same precedence as "not" and unary minus.
empty A evaluates to true if:

  A is null
  A is a zero-length String
  A is a zero-length array
  A is a List and ((List) A).isEmpty()
  A is a Map and ((Map) A).isEmpty()

otherwise empty A evaluates to false
Comment 1 Nathan Abramson 2002-04-14 23:35:20 UTC
The empty EL operator has been added as EmptyOperator.java