In this and this question I learned how to pass simple definitions like a location from my main file to a e.g. beameroutertheme.
However this approach fails for longer strings or text blocks, in this example
"Hello World!"
main.tex
\documentclass{beamer}
\author{George Orwell}
\title{Animal Farm}
\date{\today}
\institute[TUD]
\usetheme[myText=Hello World!]{tudrobert}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
\end{document}
which can then be used in the template definitions:
beamerthemetudrobert.tex
\mode<presentation>
\DeclareOptionBeamer{myText}{\PassOptionsToPackage{myText=#1}{beamerinnerthemetudrobert}}
\ProcessOptionsBeamer
\usepackage{graphicx}
\usepackage[absolute,overlay]{textpos}
\usepackage{calc}
\usepackage{fontspec}
\useinnertheme{tudrobert}
\setbeamertemplate{navigation symbols}{}
\setbeamertemplate{blocks}[rounded][shadow=true]
\mode<all>
And finally the theme where I'd like to insert the text:
beamerinnerthemetudrobert.tex
\mode<presentation>
\DeclareOptionBeamer{myText}{\def\beamer@tudrobert@myText{#1}}
\ProcessOptionsBeamer
\defbeamertemplate*{title page}{tudrobert}{%
\usebeamerfont*{title}
\MakeUppercase{\inserttitle}\par
\vfill
{\scriptsize\insertauthor}
\vfill
\beamer@tudrobert@myText
\vfill
\insertdate
}
\mode<all>
As you can see, the text is not parsed correctly.

What is the appropriate way to pass text defined in the main file to beamer themes?

\insertsubtitle– samcarter_is_at_topanswers.xyz Apr 27 '15 at 15:18