How to give a name (not just label) to an equation

Question

I have the following code:

\documentclass{article}
\usepackage[top = 2cm, bottom = 1cm, left = 1.5cm, right = 1.5cm, includefoot]{geometry}
\usepackage[italic = true]{derivative}
\usepackage{physics}
\usepackage{tcolorbox}
\definecolor{blizzardblue}{rgb}{0.4, 0.6, 0.8} 
\definecolor{bleudefrance}{rgb}{0.19, 0.55, 0.91}
\newcommand{\Emph}[1]{{\bfseries #1}}
\NewDocumentCommand{\bline}{somo}{%
\IfBooleanTF{#1}{
    \begin{tcolorbox}[
    colback = blizzardblue!30!white,
    colframe = blizzardblue!30!white,
    ]
    \setlength{\abovedisplayskip}{0pt}
    \begin{flalign}
        \IfValueT{#2}{\text{\Emph{#2}}} && #3 &&
    \end{flalign}
    \IfValueT{#4}{\emph{#4}}
    \end{tcolorbox}\noindent%
}{
    \begin{tcolorbox}[
        colback = blizzardblue!30!white,
        colframe = blizzardblue!30!white,
    ]
    \setlength{\abovedisplayskip}{0pt}
    \begin{flalign}
        \IfValueT{#2}{\text{\Emph{#2}}} && #3 &&
    \end{flalign}
    \IfValueT{#4}{\emph{#4}}
    \end{tcolorbox}\noindent%
}}
\usepackage{hyperref}
\newcommand{\eq}[1]{{\hyperref[#1]{eq. ({\color{bleudefrance}\ref*{#1}})}}}
\begin{document}
\bline[Gauss's Law]{
    \label{gaussLaw}
    \nabla\vdot\vb{E} = \frac{\rho}{\epsilon_0}
}
As you can see in \eq{gaussLaw}, it says "1" instead of "Gauss's Law".
\end{document}

that produces

What I need is: adapt the code in way that \eq gives (produces) "Gauss's Law" instead of "eq (1)". Comment: \tag may not be the solution I'm looking for because I want a number for the equation. I want to be able to refer to that equation by it's number (1) or by it's name (Gauss's Law) I hope I have explained myself. Please tell me if more information is needed. Thanks for reading.

If you're still giving it a number, why can't you just type out "Gauss's Law"? Are you wanting the hyperlink? — Teepeemm, Jun 28 '23 at 01:46
Does this answer your question? Link to arbitrary part of text? — Alan Munn, Jun 28 '23 at 02:15
Somewhat related: https://tex.stackexchange.com/questions/236626/refer-to-the-name-of-an-equation-while-a-list-of-equations-is-generated-using — John Kormylo, Jun 28 '23 at 02:34

score 5 · Accepted Answer · answered Jun 28 '23 at 07:42

You can define \@currentlabelname and then use \nameref:

\documentclass{article}
\usepackage[top = 2cm, bottom = 1cm, left = 1.5cm, right = 1.5cm, includefoot]{geometry}
\usepackage[italic = true]{derivative}
\usepackage{physics}
\usepackage{tcolorbox}
\definecolor{blizzardblue}{rgb}{0.4, 0.6, 0.8} 
\definecolor{bleudefrance}{rgb}{0.19, 0.55, 0.91}
\newcommand{\Emph}[1]{{\bfseries #1}}
\makeatletter
\NewDocumentCommand{\bline}{somo}{%
\def@currentlabelname{#2}%
\IfBooleanTF{#1}{
    \begin{tcolorbox}[
    colback = blizzardblue!30!white,
    colframe = blizzardblue!30!white,
    ]
    \setlength{\abovedisplayskip}{0pt}
    \begin{flalign}
        \IfValueT{#2}{\text{\Emph{#2}}} && #3 &&
    \end{flalign}
    \IfValueT{#4}{\emph{#4}}
    \end{tcolorbox}\noindent%
}{
    \begin{tcolorbox}[
        colback = blizzardblue!30!white,
        colframe = blizzardblue!30!white,
    ]
    \setlength{\abovedisplayskip}{0pt}
    \begin{flalign}
        \IfValueT{#2}{\text{\Emph{#2}}} && #3 &&
    \end{flalign}
    \IfValueT{#4}{\emph{#4}}
    \end{tcolorbox}\noindent%
}}
\usepackage{hyperref}
\newcommand{\eq}[1]{{\hyperref[#1]{eq. ({\color{bleudefrance}\ref*{#1}})}}}
\begin{document}
\bline[Gauss's Law]{
    \label{gaussLaw}
    \nabla\vdot\vb{E} = \frac{\rho}{\epsilon_0}
}
As you can see in \eq{gaussLaw}, it says "1" instead of "Gauss's Law".
\nameref{gaussLaw}
\end{document}

How to give a name (not just label) to an equation

1 Answers1