Renaming equation name for reference is causing unwanted horizontal spaces

Question

I succeded in renaming my equation names from the german word "Gleichung" into "Formel" through the following page: https://golatex.de/formelverzeichnis-erstellen-t6688,start,8.html

This equation name is used for reference through the \autoref{} function.

Now I get unwanted horizontal spaces after and before the reference like this:

As you can see before the "F" in the reference and after the number there is a big unwanted horizontal space.

I figured out an alternative way which I am not fully happy with:

Here I am using \hyperref[Pythagoras]{Formel~}\ref{Pythagoras} to refer to the equation labeled "Pythagoras". This reference excludes the space between the equation name "Formel" and the number. But I'd like the reference to be together but without the horizontal spaces. How can I achieve this?

This is my code:

\documentclass[a4paper,13pt,twoside]{scrreprt}

\usepackage[utf8]{inputenc}
\usepackage[german]{babel}
\usepackage{hyperref}
\usepackage{amsmath}

\DeclareNewTOC[
indent=0pt,
hang=2em,
type=equation
]{loe}

\AtBeginDocument{
    \newcaptionname{german}\equationname{Formel}
    \newcaptionname{german}\listequationname{Formelverzeichnis}
}

\newcommand{\formelref}[1]{
    \begingroup
    \def\equationautorefname{Formel}
    \autoref{#1}
    \endgroup
}

\begin{document}
    \chapter{Pythagoras}
    \begin{equation}
    a^2 + b^2 = c^2
    \label{Pythagoras}
    \end{equation}
    \newline
    Der Satz des Pythagoras wird über die \formelref{Pythagoras} dargestellt. Möchte man nun die Länge von $c$ bestimmen, verwendet man die \formelref{cPythagoras}.
    \begin{equation}
    c = \sqrt{a^2 + b^2}
    \label{cPythagoras}
    \end{equation}
    \newline
    \textbf{Alternative:}
    \newline
    Der Satz des Pythagoras wird über die \hyperref[Pythagoras]{Formel~}\ref{Pythagoras} dargestellt. Möchte man nun die Länge von $c$ bestimmen, verwendet man die \hyperref[cPythagoras]{Formel~}\ref{cPythagoras}. % Alternative

\end{document}

Answer 1

As an alternative to modifying the \autoref command and providing a new, dedicated command called \formelref, I'd like to suggest that you load the cleveref package and define "Formel" as an alias for "Gleichung". Then, use the optional argument of \label to inform cleveref when an equation should be labeled 'Formel' rather than 'Gleichung' and use \cref to cross-reference either single or multiple instances of equations. In comparison, with \autoref you can only cross-reference one object at a time.

\documentclass[a4paper,13pt,twoside,ngerman]{scrreprt}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{amsmath}

\usepackage[colorlinks,allcolors=blue]{hyperref}
\usepackage[nameinlink]{cleveref}
\crefalias{formel}{equation}
\crefname{formel}{Formel}{Formeln}
\creflabelformat{formel}{#2\textup{(#1)}#3}

\begin{document}
\setcounter{chapter}{1}
\begin{equation} a^2+b^2=c^2 \label[formel]{Pythagoras}\end{equation}
\begin{equation} c=\sqrt{a^2+b^2} \label[formel]{cPythagoras} \end{equation}
\begin{equation} 1+1=2 \label{trivial} \end{equation} % observe: NO '[formel]'

\cref{Pythagoras}, \cref{Pythagoras,cPythagoras}; \cref{trivial}
\end{document}

Answer 2

As Donald pointed out, I needed to add a % after the lines and now it seems to work.

\newcommand{\formelref}[1]{%
    \begingroup%
    \def\equationautorefname{Formel}%
    \autoref{#1}%
    \endgroup%
}%

This gives me the wanted result:

Full Code:

\documentclass[a4paper,13pt,twoside]{scrreprt}

\usepackage[utf8]{inputenc}
\usepackage[german]{babel}
\usepackage{hyperref}
\usepackage{amsmath}

\DeclareNewTOC[
indent=0pt,
hang=2em,
type=equation
]{loe}

\AtBeginDocument{
    \newcaptionname{german}\equationname{Formel}
    \newcaptionname{german}\listequationname{Formelverzeichnis}
}

\newcommand{\formelref}[1]{%
    \begingroup%
    \def\equationautorefname{Formel}%
    \autoref{#1}%
    \endgroup%
}%

\begin{document}
    \chapter{Pythagoras}
    \begin{equation}
    a^2 + b^2 = c^2
    \label{Pythagoras}
    \end{equation}
    \newline
    Der Satz des Pythagoras wird über die \formelref{Pythagoras} dargestellt. Möchte man nun die Länge von $c$ bestimmen, verwendet man die \formelref{cPythagoras}.
    \begin{equation}
    c = \sqrt{a^2 + b^2}
    \label{cPythagoras}
    \end{equation}
    \newline
    \textbf{Alternative:}
    \newline
    Der Satz des Pythagoras wird über die \hyperref[Pythagoras]{Formel~}\ref{Pythagoras} dargestellt. Möchte man nun die Länge von $c$ bestimmen, verwendet man die \hyperref[cPythagoras]{Formel~}\ref{cPythagoras}. % Alternative

\end{document}