How to add indent in non-numbered section of the table of content?

Question

I'm using \setcounter{secnumdepth}{0} to show sections without any number. It works as expected, but I'd like to have some indentation to align the begin of the text.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{blindtext}

\usepackage{filecontents}
\begin{filecontents}{text1.tex}
     \section{text 1}
    \blindtext
\end{filecontents}
\begin{filecontents}{text2.tex}
    \section{text 2}
    \blindtext
\end{filecontents}
\begin{filecontents}{text3.tex}
    \section{text 3}
    \blindtext
\end{filecontents}
\begin{filecontents}{text4.tex}
    \section{text 4}
\blindtext
\end{filecontents}

\newcommand{\inputa}[1]{%
    \setcounter{secnumdepth}{0} 
    \input{#1}
    \setcounter{secnumdepth}{1}
}

\begin{document}    
\input{text1.tex}
\inputa{text2.tex}
\input{text3.tex}
\input{text4.tex}

\tableofcontents

\end{document}

Giving the following result:

I'd like all the words "text" to be aligned.

[EDIT after Phelype Oleinik answere]

Regarding the suggested non-starred approach: I will not manually change my numerous sections consisting of a lot of different .tex files. I've once tried to make it automated writing my \inputa command with something like:

\newcounter{starlab}%counter for a label to use with \nameref
\newcommand{\inputa}[1]{%
    \let\origsection\section
    \renewcommand{\section}{% force starred section
        \@ifstar{\origsection*}{\origsection*}}
    \input{#1}
    \refstepcounter{starlab}\label{sec:\thestarlab}
    \addcontentsline{toc}{section}{\protect\numberline{}\nameref{sec:\thestarlab}}
    \let\orgisection\section
    }

But…

1. I cannot compile it anymore, I don't know why (Argument of \@ssect has an extra } error).
2. yersterday it worked on my document with the desired appearance, but I still had a problem with hypperef since the label points at the end of the text, and those texts are sometimes quite long.

Answer 1

You can do it with etoc.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{blindtext}
\usepackage{hyperref}
\usepackage{etoc}
\etocsetstyle{section}
    {}
    {\etocifnumbered
      {\etocsavedsectiontocline{\numberline{\etocnumber}\etocname}{\etocpage}}
      {\etocsavedsectiontocline{\numberline{}\etocname}{\etocpage}}%
    }
    {}
    {}
\begin{document}
\tableofcontents
\section{Alpaca}
\blindtext
\setcounter{secnumdepth}{0}
\section{Capybara}
\setcounter{secnumdepth}{1}
\blindtext
\section{Ant}
\blindtext
\end{document}

Here is with MWE from OP.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{blindtext}
\usepackage{etoc}
\etocsetstyle{section}
    {}
    {\etocifnumbered
      {\etocsavedsectiontocline{\numberline{\etocnumber}\etocname}{\etocpage}}
      {\etocsavedsectiontocline{\numberline{}\etocname}{\etocpage}}%
    }
    {}
    {}

\usepackage{filecontents}
\begin{filecontents}{text1.tex}
     \section{text 1}
    \blindtext
\end{filecontents}
\begin{filecontents}{text2.tex}
    \section{text 2}
    \blindtext
\end{filecontents}
\begin{filecontents}{text3.tex}
    \section{text 3}
    \blindtext
\end{filecontents}
\begin{filecontents}{text4.tex}
    \section{text 4}
\blindtext
\end{filecontents}

\newcommand{\inputa}[1]{%
    \setcounter{secnumdepth}{0} 
    \input{#1}
    \setcounter{secnumdepth}{1}
}

\begin{document}    
\input{text1.tex}
\inputa{text2.tex}
\input{text3.tex}
\input{text4.tex}

\tableofcontents

\end{document}

Answer 2

I changed your approach a bit... Instead of changing secnumdepth in the middle of the document, you can use the starred version \section* to add a numberless section.

(If you insist on changing secnumdepth, see the second part of the answer).

Then you can use \addcontentsline{toc}{section}{text 2} to add this section's entry to the ToC.

Better yet! You can use

\section*{text 2}
\addcontentsline{toc}{section}{\numberline{}text 2}

and the indentation will be preserved in the ToC, as you want:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{blindtext}

\begin{document}
\section{text 1}
\blindtext

\section*{text 2}
\addcontentsline{toc}{section}{\numberline{}text 2}
\blindtext

\section{text 3}
\blindtext
\section{text 4}
\blindtext

\tableofcontents

\end{document}

To make things less manual, you can define a command, say, \nonumbersection to do the whole thing:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{blindtext}


\makeatletter
\def\nonumbersection{\@dblarg\@nnsection}
\def\@nnsection[#1]#2{%
  \section*{#2}%
  \sectionmark{#1}%
  \addcontentsline{toc}{section}{\numberline{}#1}}
\makeatother

\begin{document}
\section{text 1}
\blindtext

\nonumbersection{text 2}
\blindtext

\section{text 3}
\blindtext
\section{text 4}
\blindtext

\nonumbersection[t5]{text 5}
\blindtext

\tableofcontents

\end{document}

---

As per your edit, if you insist on keeping the secnumdepth approach:

Your definition of \inputa is almost correct, except:

• The \refstepcounter, \label, and \addcontentsline commands should me inside the new definition of \section, because this \section command will be inside the \input, and if you place the \label after the \input it's too late, and the reference will be wrong (as you concluded yourself);

• The de-redefinition of \section is incorrect. You had \let\orgisection\section, which will make a copy of \section into \orgisection, but you want the opposite, so it's \let\section\orgisection;

• It's \origsection :P

After the corrections, your code works as expected:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage{blindtext}

\usepackage{filecontents}
\begin{filecontents}{text1.tex}
\section{text 1}
\blindtext
\end{filecontents}
\begin{filecontents}{text2.tex}
\section{text 2}
\blindtext
\end{filecontents}
\begin{filecontents}{text3.tex}
\section{text 3}
\blindtext
\end{filecontents}
\begin{filecontents}{text4.tex}
\section{text 4}
\blindtext
\end{filecontents}

\makeatletter
\newcounter{starlab}%counter for a label to use with \nameref
\newcommand{\inputa}[1]{%
    \let\origsection\section
    \def\section{%
      \refstepcounter{starlab}%
      \label{sec:\thestarlab}%
      \addcontentsline{toc}{section}{\protect\numberline{}\nameref{sec:\thestarlab}}
      \@ifstar{\origsection*}{\origsection*}}
    \input{#1}
    \let\section\origsection}
\makeatother

\begin{document}
\input{text1.tex}
\inputa{text2.tex}
\input{text3.tex}
\input{text4.tex}

\tableofcontents

\end{document}

Answer 3

Using unnumberedtotoc:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{blindtext}
\usepackage[indentunnumbered]{unnumberedtotoc}%<----------
\usepackage{hyperref}
\begin{document}
\tableofcontents
\section{Alpaca}
\blindtext
\addsec[Wombat]{Capybara}
\blindtext
\section{Ant}
\blindtext
\end{document}