Changing to another language programmatically

Problem

In the course of a questionnaire, you want to change to another language based on an answer to a previous question.

Solution

Use a CALCUL question as in:

Q1
% question

[EN]In which language do you want to fill out the questionnaire?
[FR]En quelle langue voulez-vous compléter le questionnaire?
% note
% categories

[EN]English[FR]Anglais
[EN]French[FR]Français
% skips
% condition
% open-end
! ==================================================
SWITCH CALCUL
% question

SWITCH =
{
$formdata{_lang} = ( $QLANGUE == 1 ) ? "FR" : "EN";
$_callweb = _insere_dans_chaine("_lang",$formdata{_lang},$_callweb);
}
% note
% categories
% skips
% condition
% open-end
! ==================================================

Discussion

The $_lang system variable controls the language in which the questionnaire is displayed. It contains a two-letter code from the ISO classification of languages.

The CALCUL question above attributes "EN" to $_lang if Q1 equals 1 and "FR" otherwise. This scheme can be extended to more languages or other sources of data such as prepopulated information: if you have imported information on the respondent's preferred language of communication, you can use it in a similar CALCUL to adjust the language of the questionnaire accordingly.