Feature Proposal: Add default value to STARTSECTION

Motivation

In trunk you can now set a default value for a TMPL:P, the default is set in the TMPL:DEF:

%TMPL:DEF{"x" y="1"}% x%y%z %TMPL:END% 

(see http://trunk.foswiki.org/System/SkinTemplates#Block_definition_parameters)

This principle does not exist yet with STARTSECTION / INCLUDE.

We should make sure that TMPL:P, Set and sections work the same way.

Problem

Let's say I want to have a section where a value should have a default size of 10.

Currently I can only say: INCLUDE{"topic" size="10"}, and in STARTSECTION handle this with %size%. But this breaks if size is not passed by INCLUDE.

To get around this, you need this construction inside the section:

%STARTSECTION{"select"}%
size='%IF{
    "defined size AND $size"
    then="%size%"
    else="10"
}%'
%ENDSECTION{"select"}%

It is too complex and error prone.

Description and Documentation

Desired syntax:

%STARTSECTION{"select" size="10"}%
size='%size%'
%ENDSECTION{"select"}%

where the default value is used as long as param size is not passed.

WhatDoesItAffect:

%WHATDOESITAFFECT%

edit

Implementation

-- Contributors: ArthurClemens - 24 May 2012

Discussion

I agree - its all part of what 1.2.0 is about for me - coalessing the functionalities of paramaterised variables, TMPL and sectional includes, so that in a future release we can see what can be merged.

-- SvenDowideit - 24 May 2012

For what it's worth, CrawfordCurrie 's parameterized variables work means (I think) that this should work also (less elegant, but not quite as less-elegant as the IF solution):

%STARTSECTION{"select"}%
size='%size{default="10"}%'
%ENDSECTION{"select"}%

-- PaulHarvey - 25 Jun 2012 - 05:33

Michael came across a problem that I'm hoping we can make a unit test for, but other than that - this feature is either implemented, or if we find a mis-compatibility, will need re-thinking.

At its root, we are changing what preferences are set when INCLUDE-chaining.

-- SvenDowideit - 26 Jun 2012

Sven (or Michael) - can you elaborate on what the problem is?

-- KipLubliner - 28 Jun 2012

Kip - see Tasks.Item11969

-- SvenDowideit - 30 Jun 2012