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From: Peter Rolf <indiego@gmx.net>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Re: Test whether variable has been set
Date: Sun, 27 May 2007 15:26:37 +0200	[thread overview]
Message-ID: <4659870D.9080501@gmx.net> (raw)
In-Reply-To: <e65d34bf0705270415m3721c268x52e8cb813086b49e@mail.gmail.com>

Hi Elliot,

Elliot Clifton schrieb:
> Hi,
> 
> How can test whether a variable has been set? I couldn't find any
> reference to this in the wiki?
>
What do you mean by "set"?

I use

\doifnothing{\getvariable{foo}{bar}}
  {foo:bar contains nothing.\par}%
\doifsomething{\getvariable{foo}{bar}}
  {foo:bar contains something.\par}%
\doifelsenothing{\getvariable{foo}{bar}}
  {foo:bar contains nothing.\par}
  {foo:bar contains something.\par}%

to test, if a defined(!) variable contains something.

If you want to test if a variable is defined, you can use

\doifnotvariable{foo}{bar}
  {foo:bar is undefined.\par}%
\doifvariable{foo}{bar}
  {foo:bar is defined.\par}%
\doifelsevariable{foo}{bar}
  {foo:bar is defined.\par}
  {foo:bar is undefined.\par}%

Never used these macros, as I always define default values for my variables.


HTH, Peter


> TIA,
> 
> Elliot
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive  : https://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________
> 

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________


  reply	other threads:[~2007-05-27 13:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-27 11:15 Elliot Clifton
2007-05-27 13:26 ` Peter Rolf [this message]
2007-05-27 14:58 Elliot Clifton
2007-05-27 15:55 ` Aditya Mahajan
2007-05-27 16:15   ` Hans Hagen
2007-05-27 18:15 ` Peter Rolf

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