Width of \chapter section with titlesec

Question

I use the titlesec package for styling the sectioning commands. But I have a problem with the chapter width or right margin:

The width of the text should only reach to the blue line, "Organisation" and "Display" should break. I know \\ is an option, but in the footer is also the chapter name referred:

So, if I use \\, the text in the footer is: "Konzepte für die semantische"...

The styling ist:

% > formats: \chapter
\titleformat{\chapter}[display]%
{\usekomafont{chapter}}%
{\vspace{-8em}\raggedleft{%
    {\color{ctcolorchapterline}%
        \rule[-5pt]{2pt}{5cm}}\quad%
    {\color{ctcolorchapternum}
        \fontsize{60}{60}\selectfont\thechapter}%
    }%
}%
{-2.1em}%
{\raggedright}%
[\phantomsection]

Answer 1

You can use the explicit option for titlesec to place the title inside a \parbox of the desired length; notice that now you need to use #1 (typically in the last mandatory argument for \titleformat) to get the title for the sectional unit. I used \textwidth-3em as the width for the box, but you can change this value according to your needs. In the example below I provided some definitions for the colors used since they were not given in the question:

\documentclass{scrbook}
\usepackage{xcolor}
\usepackage[explicit]{titlesec}
\usepackage{lmodern}% just for the example
\usepackage{lipsum}% just for the example
\usepackage{hyperref}

\colorlet{ctcolorchapterline}{cyan}
\colorlet{ctcolorchapternum}{cyan}

\titleformat{\chapter}[display]%
  {\usekomafont{chapter}}%
  {\vspace{-8em}\raggedleft{%
    {\color{ctcolorchapterline}%
        \rule[-5pt]{2pt}{5cm}}\quad%
    {\color{ctcolorchapternum}
        \fontsize{60}{60}\selectfont\thechapter}%
    }%
  }%
  {-2.1em}%
  {\parbox[b]{\dimexpr\textwidth-3em\relax}{\raggedright#1}}%
  [\phantomsection]

\begin{document}

\chapter{A test chapter with a long title that will span two lines}
\lipsum[4]

\end{document}

As egreg has pointed out in his comment, one can avoid using the explicit option using an auxiliary macro:

\documentclass{scrbook}
\usepackage{xcolor}
\usepackage{titlesec}
\usepackage{lmodern}% just for the example
\usepackage{lipsum}% just for the example
\usepackage{hyperref}

\colorlet{ctcolorchapterline}{cyan}
\colorlet{ctcolorchapternum}{cyan}

\newcommand\mychapformat[1]{%
  \parbox[b]{\dimexpr\textwidth-3em\relax}{\raggedright#1}}
\titleformat{\chapter}[display]%
  {\usekomafont{chapter}}%
  {\vspace{-8em}\raggedleft{%
    {\color{ctcolorchapterline}%
        \rule[-5pt]{2pt}{5cm}}\quad%
    {\color{ctcolorchapternum}
        \fontsize{60}{60}\selectfont\thechapter}%
    }%
  }%
  {-2.1em}%
  {\mychapformat}%
  [\phantomsection]

\begin{document}

\chapter{A test chapter with a long title that will span two lines}
\lipsum[4]

\end{document}

I added \sectfont to your definitions so you can keep the boldfaced sansseerf font used by default in KOMA sectional units:

\documentclass{scrbook}
\usepackage{xcolor}
\usepackage{titlesec}
\usepackage{lmodern}% just for the example
\usepackage{lipsum}% just for the example
\usepackage{hyperref}

\colorlet{ctcolorchapterline}{cyan}
\colorlet{ctcolorchapternum}{cyan}

\newcommand\mychapformat[1]{%
  \parbox[b]{\dimexpr\textwidth-3em\relax}{\raggedright#1}}
\titleformat{\chapter}[display]%
  {\usekomafont{chapter}\sectfont}%
  {\vspace{-8em}\raggedleft{%
    {\color{ctcolorchapterline}%
        \rule[-5pt]{2pt}{5cm}}\quad%
    {\color{ctcolorchapternum}
        \fontsize{60}{60}\selectfont\thechapter}%
    }%
  }%
  {-2.1em}%
  {\mychapformat}%
  [\phantomsection]

\begin{document}

\chapter{A test chapter with a long title that will span two lines}
\lipsum[4]

\end{document}

Notice that titlesec and KOMA-Script might not be fully compatible (you'll get a warning from the KOMA classes when loading titlesec); see Incompatibilities between KOMA-Script and titlesec