Referencing Enumerate List

Question

First off, I realise there are a lot of questions on this topic, and I've had an extensive look at finding an answer to my question, but haven't found one; if there is a duplicate on this site, my sincere apologies. Now for the actual question...

I would like to create an enumerated list in a way that I can choose the label and then have a hyperref reference to this label. The accepted answer on this SE question here almost does exactly what I want. The answer gives the following MWE.

\documentclass{article}
\usepackage{enumitem}
\begin{document}
\begin{enumerate}[label=\textbf{S.\arabic*}]
\item a
\item \label{l} b
\item c. goto \ref{l}
\end{enumerate}
\end{document}

Now, I would like to do exactly this, but I don't want to have to write label=... each time. Previously, I had used something like

\newcommand{\alphanumbering}{\renewcommand{\labelenumi}{(\textit{\alph{enumi}})}}

and then just prior to typing begin{enumerate} I would type \alphanumbering. When I use \ref, however, I just get the counter (which is enumi?), and I can't even use something like \alph{\ref{1}}.

I'd then like to extend this further, to write something like \alphaarabicnumbering before enumerate, where

\newcommand{\alphaarabicnumbering}{
    \renewcommand{\labelenumi} {(\textit{\alph{enumi}})}
    \renewcommand{\labelenumii}{\arabic{enumii}.} }

This then gives a list with first level (a), (b), ... and second level 1., 2., .... For example,

(a) foo
    1. bar
    2. foobar

I'd like to reference "foobar" as (a.2), and other lines similarly. (Note that a naive reference would be (a)2, which is not what I want.)

For reference, see also this SE question.

Answer 1

... I don't want to have to write label=... each time.

Since you're loading the enumitem package, you may want to make use of its \newlist and \setlist macros to create a custom enumerated environment that does the special labelling automatically. The solution is fully compatible with the hyperref package.

\documentclass{article}

\usepackage{enumitem}
\newlist{senum}{enumerate}{1} % create a new, 1-level enumerated environment
\setlist[senum]{label=\textbf{S.\arabic*}} % define the labels

\begin{document}
\begin{senum}
\item a
\item \label{x} b
\item c.\ goto \ref{x}
\end{senum}
\end{document}

Answer 2

Here is a MWE to give a few more details. To those who are very familiar with TeX, Mico's answer and a brief glance at the documentation (which has some examples, but not necessarily exactly what I want) will be sufficient, but for those like myself we need to do a little bit of testing to see exactly what's going on! Here it is below.

\documentclass[]{article}
\usepackage{enumitem}
\newlist{list1}{enumerate}{2}
\setlist[list1,1]{label=\arabic{list1i},ref=\arabic{list1i}}
\setlist[list1,2]{label=\alph{list1ii},ref=(\arabic{list1i}.\alph{list1ii})}
\begin{document}
\begin{list1}
    \item \label{1} ITEM 1
    \item \label{2} ITEM 2
    \begin{list1}
        \item \label{3} ITEM (2.a)
    \end{list1}
\end{list1}
\ref{1} \ref{2} \ref{3}
\end{document}