PmWiki | PITS / 01529: new conditional markup condition "empty" (original) (raw)

Summary: new conditional markup condition "empty"

Created: 2025-11-11 19:17

Status: Closed, added for 2.5.4

Category: Feature

Assigned:

Priority: 3

Version: latest

OS: n/a

Description: I propose

(:if empty STRING:)

true if VARIABLE or STRING is empty or does not exist

to replace the construct

(:if equal "STRING" "":)

simon November 11, 2025, at 07:17 PM

Should a value of "0" be considered empty, like the PHP empty() function? Or these values? Petko November 11, 2025, at 07:33 PM

(:if empty:) true (:if empty :) true (:if empty "":) true (:if empty {$NoSuchVar}:) true (:if empty "{$NoSuchVar}":) true (:if empty 0:) false, string is '0' (:if empty "0":) false, string is '0' (:if empty false:) false, string is 'false' (:if empty "false":) false, string is 'false' (:if empty var=value:) false, string is 'var=value' (:if empty var=0:) false, string is 'var=0' (:if empty var="":) false, string is 'var=""'

No, I see this as 'string' comparison, I've added what I would expect to be returned above.
true and false can be evaluated using the existing Conditional Markup (:if expr EXPRESSION :)

This PITS does not ask for numeric evaluation (but see something similar at 01469)