General ⇒ case-statement conditional text

[Shea12Shea12]

Hello,

In my continued search for various ways of creating conditional text, I'm looking for a good way to handle a case statements. One way of handling it is to use nested if statements, but the more cases your have the uglier/more-cumbersome it becomes, and I am also getting a weird spacing issue where the text is placed (large spacing after the colon).

Is there a smarter way of handling this?

Thank you for taking the time to read and reply,
Alan

Example nested statement, spacing issue

Code: Select all

\documentclass{article}
\usepackage{etoolbox}

\begin{document}
\newbool{customer1}
\newbool{customer2}
%...
\newbool{customerN}

This is general text all customers get.

\booltrue{customer1}
This is special information:
\ifboolexpr{bool{customer1}}{
customer1 specific information
}{
\ifboolexpr{bool{customer2}}{
customer2 specific information
}{
\ifboolexpr{bool{customer2}}{
customerN specific information
}{
No previous customers were matched
}}}

\boolfalse{customer1}
\booltrue{customerN}
Notice the larger spacing after the colon using customerN

This is special information:
\ifboolexpr{bool{customer1}}{
customer1 specific information
}{
\ifboolexpr{bool{customer2}}{
customer2 specific information
}{
\ifboolexpr{bool{customerN}}{
customerN specific information
}{
No previous customers were matched
}}}

\bigskip

If the text is on a new line, no spacing issue
\booltrue{customer1}
\boolfalse{customerN}

\ifboolexpr{bool{customer1}}{
customer1 specific information
}{
\ifboolexpr{bool{customer2}}{
customer2 specific information
}{
\ifboolexpr{bool{customer2}}{
customerN specific information
}{
No previous customers were matched
}}}

\boolfalse{customer1}
\booltrue{customerN}

\ifboolexpr{bool{customer1}}{
customer1 specific information
}{
\ifboolexpr{bool{customer2}}{
customer2 specific information
}{
\ifboolexpr{bool{customerN}}{
customerN specific information
}{
No previous customers were matched
}}}

\end{document}

[Stefan Kottwitz]

Hi Alan,

that's an excellent test example! Here's the improved code:

Code: Select all

\documentclass{article}
\usepackage{etoolbox}

\begin{document}
\newbool{customer1}
\newbool{customer2}
%...
\newbool{customerN}
\boolfalse{customer1}
\booltrue{customerN}
This is special information:
\ifboolexpr{bool{customer1}}{%
customer1 specific information
}{%
\ifboolexpr{bool{customer2}}{%
customer2 specific information
}{%
\ifboolexpr{bool{customerN}}{%
customerN specific information
}{%
No previous customers were matched
}}}
\end{document}

In text, the end of a line is like a white space. So just take care that your macros don't insert line spaces just because the code line ends. Just comment out the line ending by a % where it should not cause a white space.

That's the reason why you often can see percent signs at the end of lines in longer LaTeX macros that generate text, to avoid generating spaces. After a while one gets used to it and ends every macro code line with a % because the "end of line space" is only needed in text.

Stefan

[Shea12Shea12]

Thank you!