gistfile1.txt

\documentclass{report}
\makeatletter
\usepackage{pgfopts}

% This is what we do here. We define commands like \@wgetdoc@title@maintitle
% that we need to call manually to execute their content.
\newif\if@wgetdoc@title@ownpage
\pgfkeys{
    /wgetdoc/title/.cd,
    % maintitle/.code={\ifx#1\@empty\else\edef\@wgetdoc@title@maintitle{#1}\fi},
    maintitle/.store in=\@wgetdoc@title@maintitle,
    maintitle/.value required,
    subtitle/.store in=\@wgetdoc@title@subtitle,
    author/.store in=\@wgetdoc@title@author,
    filename/.store in=\@wgetdoc@title@filename,
    ownpage/.is if=@wgetdoc@title@ownpage
}

\renewcommand{\title}[1][]{%

    % The following command is a shortcut and marginally quicker than
    % \pgfkeys{/wgetdoc/title/.cd, #1}
    % The command cannot end with the trailing / though.
    \pgfqkeys{/wgetdoc/title}{#1}

    \@ifundefined{@wgetdoc@title@filename}{

        % Do not use the following check. This macro is only available in
        % xkeyval and allows just checking if a key is defined in a family from
        % a list of families.
        \@ifundefined{@wgetdoc@title@maintitle}{
            \ClassError{wgetdoc}{You did not specify a main title}{}
        }{}

        % Check if maintitle is empty as it: maintitle=,subtitle=lorem
        % or maintitle={},subtitle=lorem
        % No need to check further as pgfkeys trims white spaces and
        % checks performed either by \ifblank (etoolbox) or
        % \@ifmtarg (ifmtarg) are lost
        \ifx\@wgetdoc@title@maintitle\@empty
            \ClassError{wgetdoc}{The main title you specified is empty}{}
        \fi

        % Custom horizontale rule only local to this environment
        \newcommand{\@wgetdoc@title@hrule}{\rule{\linewidth}{1mm}}

        % If this boolean key is absent of the title command, this will return
        % false. If it is only present, it will return true. Any
        % value other than 'true' or 'false' is non accepted and will make the
        % compilation crash.
        \if@wgetdoc@title@ownpage
            \begin{titlepage}
                \begin{center}

                    \@wgetdoc@title@hrule%
                    \vspace{0.4cm}

                    % We always need to define \par in scope for a font size
                    % change, otherwise, if the title is ever longer than a
                    % line, it will wrap to the next line with huge characters
                    % on a normal baseline.
                    {\Huge\textbf{\@wgetdoc@title@maintitle}\par}%

                    \vspace{0.4cm}%
                    \@wgetdoc@title@hrule

                    \@ifundefined{@wgetdoc@title@subtitle}{}{
                        \vspace{1.5cm}
                        {\Large{\@wgetdoc@title@subtitle}\par}%
                    }

                    \@ifundefined{@wgetdoc@title@author}{}{
                        % Adds vertical space which will not be suppressed at the
                        % beginning or end of a page. Text following that statement
                        % will be at the bottom of the page.
                        \vspace*{\fill}
                        {\emph{Author: \@wgetdoc@title@author}\par}%
                    }

                \end{center}
            \end{titlepage}%
        \else
            \begin{center}
                {\huge\textbf{\@wgetdoc@title@maintitle}\par}
                \@ifundefined{@wgetdoc@title@subtitle}{}{
                    {\large{\@wgetdoc@title@subtitle}\par}%
                }
            \end{center}
            \@ifundefined{@wgetdoc@title@author}{}{
                {\emph{Author: \@wgetdoc@title@author}\par}%
            }
            \@wgetdoc@title@hrule%
        \fi

    }{
    }
}


\usepackage{fancyhdr}
\newcommand{\@wgetdoc@header@centervalue}{}
\fancypagestyle{plain}{

    \fancyhf{}
    \@ifundefined{@wgetdoc@title@subtitle}{}{
        \renewcommand{\@wgetdoc@header@centervalue}{\@wgetdoc@title@subtitle}
    }
    \fancyhead[C]{\@wgetdoc@header@centervalue}
}
\pagestyle{plain}


\usepackage{lipsum}
\makeatother
\begin{document}

    \title[maintitle=Some title,
          subtitle=\textsc{some sub},
          author=This is me,ownpage=true]

    \chapter{My chapter name}

    \section{My section name}

    \lipsum[4-57]



\end{document}