How to load user defined content to be used in a template?

Question

I'm writing a template which uses the report class and customizes the typesetting with several packages. I'm defining some data in a separate user-data.tex file which is loaded just after documentclass:

\def\thesis{Master} %<PhD> or <Master>
\def\thesistitle{The title of the thesis}
\def\author{AName AFirst ASecond}
\def\authormail{aname@univ.edu}
\def\school{Master and Doctoral School}
\def\date{City, month year}
\def\logo-university{univ.pdf}

Those variables/constants are used to provide two different titlepages, to be included in the footer with titlesec, or used by the user at any time.

Is it ok to do it like that (using just \def)? Or should I use \global, \newcommand... or any other ? Would you place them in any other format rather than plain tex?

---

After the comments, I changed to \newcommand* and renamed some of the macros:

\newcommand*\thesis{Master} %<PhD> or <Master>
\newcommand*\thesistitle{The title of the thesis}
\newcommand*\authors{AName AFirst ASecond}
\newcommand*\authorsmail{aname@univ.edu}
\newcommand*\school{Master and Doctoral School}
\newcommand*\titledate{City, month year}
\newcommand*\university{univ.pdf}

---

After the answer by @Andrew, I'm using

\providecommand*\@school{No SCHOOL defined}
\newcommand*\School[1]{\renewcommand*\@school{#1}}

just in the beginning of the package, to let the user either define \newcommand*\@school{Something} before loading it, or \School{Something} after doing so.

---

As @barbara guessed, I moved the template to a *.sty which I'm loading as a package:

mypkg.sty

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{mypkg}

%If not previously defined, default value applied
\providecommand*{\@mythesis}{No THESIS TYPE defined}
\providecommand*{\@myauthor}{No AUTHOR defined}
%Command to modify the field at any point after this
\newcommand*\MyThesis[1]{\renewcommand*\@mythesis{#1}}
\newcommand*\MyAuthor[1]{\renewcommand*\@myauthor{#1}}
%Command to access the field
\newcommand*\showDF[1]{\csname @#1\endcsname}

%The content may be supplied in a separate file with \Thesis
\@input{data.dat}

\endinput

main.tex

\documentclass[a4paper,titlepage,11pt,twoside,openright]{report}

% A field may defined before loading the package
\makeatletter
\newcommand\@mythesis{My title before loading}
\makeatother
%If it not defined, the package does it
\usepackage{mypkg}

\begin{document}

% The variable may be directly accessed
\makeatletter\@mythesis\makeatother
% The content may be rewritten
\MyThesis{PhD}
% Reading with the provided command
\showDF{mythesis}
\showDF{myauthor}

\end{document}

It works. The user can define the content prior to loading the package, or either in a separate file or at any point after doing so with a 'helper command'. However, I'd like to:

-Use a command to automatically define the commands associated to a field. New question here.

-Give the user the ability to give the field as an option when loading the package. I tried with xkeyval:

\define@key{fam}{thesis}[Master]{\Thesis{#1}}
\ProcessOptionsX<fam>

changing the loading in the main file to:

\usepackage[thesis=PhD]{mypkg}

The above code works, except for the fields which have more than a word, since the spaces between them are removed. How can I make it work with, i.e. \usepackage[title=A title with several words]{mypkg}. I tried with {A title with several words} and "A title with several words" but It doesn't work.

It can not be made

---

Using the approach in this answer, I have now this 'factory' function to create all the commands at once:

\usepackage{etoolbox}
\newcommand\forcsvlistargs[2]{ \expandafter\providecommand\csname \detokenize{#1}aux\endcsname[1]{
 \csname \detokenize{#1}\endcsname##1\relax}
 \forcsvlist{\csname \detokenize{#1}aux\endcsname}{#2}
}
\newcommand\newDF[2]{ \expandafter\providecommand\csname th#1\endcsname{No \MakeUppercase{#2} defined}
 \expandafter\newcommand\csname TH#2\endcsname[1]{\expandafter\renewcommand\csname th#1\endcsname{##1}} }

\forcsvlistargs{newDF}{{{typ}{type}}, {{date}{date}}, {{tit}{title}}, {{sch}{school}}, 
{{aut}{author}}, {{eaut}{eauthor}} }

Answer 1

I have some (internal) classes that do something like this. What I do is first define a command like:

\newcommand\School[1]{\def\@school{#1}}

so that the "user" can use \School{My wonderful school} to overwrite the defaults. Internally, the class uses \@school whenever it needs to print the name of the school.

Next, if this is reasonable I have the class set a reasonable default for the school by having a line like

\School{My Wonderful School}

in the class. In fact, it is probably better form to use

\providescommand\@school{My Wonderful School}

although using the "helper command" is clearer, I think.

One place where I use this is for tutorial sheets where it happens that many of these variables depend on something else. For these cases I define an option to the class for setting all of these variables in one hit. So the "user" starts their file with

\documentclass[somecourse,solutions]{mytutorials}

and then inside mytutorials.cls I have

\DeclareOption{somecourse}{
  \CourseName{An exciting counrse}
  \Semester{Semester 2}
  \CourseNumber{Math 987123}
}
\DeclareOption{solutions}{
    ...
}

To process all of the options you need something like:

\DeclareOption*{\PassOptionsToClass{\CurrentOption}{article}}
\ProcessOptions

This allows me to piggyback off article.cls and pass it options that are not defined in my file.

Finally, depending on your use-case, you might want to automatically load a set of defaults from a file in the current directory. If you use \include or \input then you will run into problems when the file does not exist. Instead you can use \@input inside your class file:

\@input{defaults.dat}

This will load the file "defaults.dat" if it exists and, otherwise, do nothing. This file will be included as is, so there is a danger in using this trick because if the file contains garbage everything breaks. Of course, to cover the cases when this file does not exist, you need to set reasonable defaults.

(Btw, for your own internal variables there is really no harm in using \def -- and it is easier too. Of course, you should first make sure that you are not overwriting anything else!)