SID-00175: Conditional rendering in view.pattern.tmpl | contentheader

Status:	Answered	TWiki version:	4.2.0	Perl version:	5.008008 (linux)
Category:	CategoryRendering	Server OS:	Linux 2.6.18-53.1.14.el5pae (i386-linux-thread-multi)	Last update:	17 years ago

I want to define

TMPL:DEF{"contentheader"}

a) "Valid document" if %FORMFIELD{"valid"}% equals True
b) "Deprecated document" if %FORMFIELD{"valid"}% equals False
c) Empty string otherwise

The best I can do so far is:

%TMPL:DEF{"contentheader"}%\
%FORMFIELD{"valid" topic="%BASETOPIC%" format="This document is valid: $value" default="" alttext=""}%\
%TMPL:END%

But this is not exactly what I want.

Thanks in advance for your help.

-- GregoireLeclair - 09 Mar 2009

Discussion and Answer

Look into conditionals, either with %IF{}% (see VarIF, IfStatements), or a %CALC{$IF()}% (see SpreadSheetPlugin).

Please report back a working example once you find out so that other TWiki community members can learn.

-- PeterThoeny - 11 Mar 2009

Thanks Peter. I figured out how to build the conditional code, but the problem is the nested double quotes. Is there any way of getting rid of them?

%TMPL:DEF{"contentheadervalid"}%\
%FORMFIELD{"valid" topic="%BASETOPIC%" default="" alttext=""}%
%TMPL:END%

%TMPL:DEF{"contentheader"}%\
%CALC{"$IF($EXACT(%TMPL:P{"contentheadervalid"}%, True) == 1, Valid document, )"}%\
%CALC{"$IF($EXACT(%TMPL:P{"contentheadervalid"}%, False) == 1, Deprecated document, )"}%\
%TMPL:END%

-- GregoireLeclair - 11 Mar 2009

Either omit the quotes ( %TMPL:P{contentheadervalid}% ) or escape them ( %TMPL:P{\"contentheadervalid\"}% ).

-- PeterThoeny - 11 Mar 2009

Also, you can list multiple formulae within one CALC, such as %CALC{$IF(...)$IF(...)}%

-- PeterThoeny - 11 Mar 2009

I tried without the quotes and with escaped quotes without success.

For a given topic where valid=True, If I use this code:

%TMPL:INCLUDE{"view.pattern"}%

%TMPL:DEF{"contentheadervalid"}%\
%FORMFIELD{"valid" topic="%BASETOPIC%" default="" alttext=""}%
%TMPL:END%

%TMPL:DEF{"contentheader"}%\
%CALC{"$IF($EXACT(%TMPL:P{contentheadervalid}%, True) == 1, Valid document, )"}%\
%CALC{"$IF($EXACT(%TMPL:P{contentheadervalid}%, False) == 1, Deprecated document, )"}%\
%TMPL:END%

Then the following text is rendered:

%CALC{"$IF($EXACT(True , True) == 1, Valid document, )"}%%CALC{"$IF($EXACT(True , False) == 1, Deprecated document, )"}%

It looks like %TMPL:P{contentheadervalid}% is evaluated after the IF conditional evaluation.

Therefore, I tried to replace %TMPL:P{contentheadervalid}% with the plain text True. I got the expected result:

Valid document

I guess the challenge is to retrieve the formfield value prior to the conditional evaluation.

-- GregoireLeclair - 12 Mar 2009

Why not use a CALC IF on the form field? Such as:
$IF($EXACT(%FORMFIELD{\"valid\" topic=\"%BASETOPIC%\"}%, True), ...)

-- PeterThoeny - 12 Mar 2009

It does work if I remove the escaped quotes:

%TMPL:DEF{"contentheader"}%\
%CALC{"$IF($EXACT(%FORMFIELD{"valid" topic="%BASETOPIC%"}%, True) == 1, Valid document, )"}%<br>\
%CALC{"$IF($EXACT(%FORMFIELD{"valid" topic="%BASETOPIC%"}%, False) == 1, Deprecated document, )"}%<br>\
%TMPL:END%

Not sure exactly how the quotes are evaluated... but it works!

Thanks for your help

-- GregoireLeclair - 12 Mar 2009

Ah, yes, you are right. FORMFIELD is evaluated before CALC, so no escape of quotes in FORMFIELD is needed.

-- PeterThoeny - 12 Mar 2009

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