Adding the string "part" before the entries in the TOC

Question

I want to add the word "Part" before my entries in the toc.

I read here that I could use \renewcommand\cftpartpresnum{Part~}. I have tried adding making some modifications to the partpresnum and partleader command but it did not work.

I am using the classicthesis style, which defines the toc like this for parts: (The full style file can be seen here)

    \ifthenelse{\boolean{@parts}}%
    {%
      \renewcommand{\thepart}{\roman{part}}%
      \renewcommand{\cftpartpresnum}{\scshape}%  \MakeTextLowercase
%      \renewcommand{\cftpartaftersnum}{\cftchapaftersnum}%
%      \renewcommand{\cftpartaftersnumb}{\quad}%
%      \setlength{\cftpartnumwidth}{\cftpartnumwidth}
      \renewcommand{\cftpartfont}{\color{Maroon}\normalfont}%
      \renewcommand{\cftpartpagefont}{\normalfont}%
      \ifthenelse{\boolean{@dottedtoc}}{\relax}%
      {%
        \renewcommand{\cftpartleader}{\hspace{1.5em}}% 
        \renewcommand{\cftpartafterpnum}{\cftparfillskip}%
      }%        
      \setlength{\cftbeforepartskip}{1em}%
      \setlength{\cftbeforechapskip}{.1em}%
      \setlength{\beforebibskip}{\cftbeforepartskip}%
     }{\relax}
    % chapters
    \ifthenelse{\boolean{@nochapters}}%
        {\relax}%
        {%
            \renewcommand{\cftchappresnum}{\scshape\MakeTextLowercase}%
            \renewcommand{\cftchapfont}{\normalfont}%
            \renewcommand{\cftchappagefont}{\normalfont}%
            \ifthenelse{\boolean{@dottedtoc}}{\relax}%
                {%
                \renewcommand{\cftchapleader}{\hspace{1.5em}}% 
                \renewcommand{\cftchapafterpnum}{\cftparfillskip}% 
            }
            %\setlength{\cftbeforechapskip}{.1em}%           
        }

... see style file for full code.

Any suggestions? Am I trying to make changes in the right place even?

The following is a reduced example. I tried using only a portion of the style file, but I couldn't get that working.

\documentclass[parskip=half,10pt,twoside]{scrbook}
\usepackage{classicthesis}


\begin{document}

\tableofcontents
\part{First test part}
\chapter{Test chapter}
\chapter{Test chapter}
\part{Second  test part}
\chapter{Test chapter}
\chapter{Test chapter}

\end{document}

Answer 1

Since classicthesis uses the tocloft package internally to generate the ToC, adding a "Part~" string can be achieved with the following code (assuming that your LaTeX installation has the latest version of the tocloft package):

\renewcommand{\cftpartpresnum}{Part~}

\newlength{\mylen} % a "scratch" length
\settowidth{\mylen}{\cftpartpresnum} % extra space
\addtolength{\cftpartnumwidth}{\mylen} % add the extra space

Notice that by redefining the \cftpartpresnum command to prepend the "Part~" string, we are adding text to the number box in addition to the part number. Thus, we need to increase the width of the box to include the additional text. One possible method is to create a new length that will store the width of the additional text and add the extra space to the \cftpartnumwidth macro.

EDIT: I'm adding the full code (based on the provided MWE) that produces the desired results. In addition, the tocloft package I used (v2.3f, 2013/05/02) is downloaded from here.

\documentclass[parskip=half,10pt,twoside]{scrbook}
\usepackage{classicthesis}

\renewcommand{\cftpartpresnum}{Part~}

\newlength{\mylen} % a "scratch" length
\settowidth{\mylen}{\cftpartpresnum} % extra space
\addtolength{\cftpartnumwidth}{\mylen} % add the extra space

\begin{document}

\tableofcontents
\part{First test part}
\chapter{Test chapter}
\chapter{Test chapter}
\part{Second  test part}
\chapter{Test chapter}
\chapter{Test chapter}

\end{document}

NOTE: For earlier versions of the tocloft package the documentation states that using it together with the KOMA classes (and others) might result in \cftpartpresnum becoming doubled in the output. This behavior is fixed (at least) since version 2.3f.

EDIT 2: Passing the parts option to the classicthesis package seems to disable this workaround. The reason is that, when using this option, the classicthesis class relies on the titlesec package in order to produce the ToC entry for parts. Luckily, the documentation for the package states that:

• \part does not encapsulates the label in the toc entry, except if you use the newparttoc option. [page 10]

and the description for the option itself further adds:

Standard parts write the toc entry number in a non standard way. You may change that with newparttoc so that titletoc or a similar package can manipulate the entry. (That works only if \part has been redefined.) [page 8]

Thus, to get the desired behavior, it's simply a matter of passing this option to the titlesec package with \PassOptionsToPackage{newparttoc}{titlesec}, prior to loading the classicthesis package.

The final code looks like this:

\documentclass[parskip=half,10pt,twoside]{scrbook}
\PassOptionsToPackage{newparttoc}{titlesec} % MUST be called before classicthesis
\usepackage[dottedtoc,floatperchapter,parts]{classicthesis}

\renewcommand{\cftpartpresnum}{Part~}

\newlength{\mylen} % a "scratch" length
\settowidth{\mylen}{\cftpartpresnum} % extra space
\addtolength{\cftpartnumwidth}{\mylen} % add the extra space

\begin{document}

\tableofcontents
\part{First test part}
\chapter{Test chapter}
\chapter{Test chapter}
\part{Second  test part}
\chapter{Test chapter}
\chapter{Test chapter}

\end{document}

and the output produced: