If you just wish to reverse the numbering - not the order - then you can use the following approach:
\documentclass{moderncv}
\usepackage{biblatex,refcount}
\makeatletter
% https://tex.stackexchange.com/q/66829/5764
\newcounter{numbibentries}
\renewbibmacro*{finentry}{\stepcounter{numbibentries}\finentry}
% https://tex.stackexchange.com/q/123805/5764
\defbibenvironment{bibliography}
{\list
{\printtext[labelnumberwidth]{% label format from numeric.bbx
\printfield{prefixnumber}%
\number\numexpr\getrefnumber{num-bib-entries}-\abx@field@labelnumber+1\relax}}
{\setlength{\topsep}{0pt}% layout parameters from moderncvstyleclassic.sty
\setlength{\labelwidth}{\hintscolumnwidth}%
\setlength{\labelsep}{\separatorcolumnwidth}%
\leftmargin\labelwidth%
\advance\leftmargin\labelsep}%
\sloppy\clubpenalty4000\widowpenalty4000}
{\endlist}
{\item}
\AtEndDocument{% Add reference at end of document to remember number of bib-entries.
\edef\@currentlabel{\thenumbibentries}\label{num-bib-entries}}
\makeatother
\moderncvstyle{classic}
\moderncvcolor{blue}
\firstname{John}
\familyname{Doe}
\addbibresource{biblatex-examples.bib}
\begin{document}
\makecvtitle
\nocite{companion,knuth:ct:a,knuth:ct:b}
\printbibliography[title={Publications}]
\end{document}
The idea is to count the number of references by tapping into each "\bibitem". Once all is counted, we insert a \label at the end of the document (using \AtEndDocument). This label is retrieved and used in a calculation (thanks to the expandable \getrefnumber from refcount) to reverse the numbering.
For multiple bibliographies per document, you could use \citesinthissection{<num>} as defined below:
\documentclass{moderncv}
\usepackage[defernumbers=true]{biblatex}
\makeatletter
\newcommand{\citesinthissection}[1]{\xdef\@totalcites{#1}}
% https://tex.stackexchange.com/q/123805/5764
\defbibenvironment{bibliography}
{\list
{\printtext[labelnumberwidth]{% label format from numeric.bbx
\printfield{prefixnumber}%
\number\numexpr\@totalcites-\abx@field@labelnumber+1\relax}}
{\setlength{\topsep}{0pt}% layout parameters from moderncvstyleclassic.sty
\setlength{\labelwidth}{\hintscolumnwidth}%
\setlength{\labelsep}{\separatorcolumnwidth}%
\leftmargin\labelwidth%
\advance\leftmargin\labelsep}%
\sloppy\clubpenalty4000\widowpenalty4000}
{\endlist}
{\item}
\makeatother
\moderncvstyle{classic}
\moderncvcolor{blue}
\firstname{John}
\familyname{Doe}
\addbibresource{biblatex-examples.bib}
\begin{document}
\makecvtitle
\nocite{companion,knuth:ct:a,knuth:ct:b}
\citesinthissection{3}% There are 3 cites in this section
\printbibliography[notkeyword=primary,title={Publications}]
\nocite{aristotle:anima,aristotle:physics}
\citesinthissection{2}% There are 2 cites in this section
\printbibliography[keyword=primary,resetnumbers=true,title={Other Publications}]
\end{document}
Remember to update the count of items whenever you add elements to your bibliography. Use the defernumbers=true global option and resetnumbers=true option from the second \printbibliography onwards. You may need to use options like keyword/notkeyword options in order to print exactly only what you want in each bibliography part.
You could write something like that
\newif\ifnumericCVbibliography
\numericCVbibliographytrue % replace true with false to disable
\newlength{\hintscolumnwidthV}
\setlength\hintscolumnwidthV{\hintscolumnwidth}
\ifnumericCVbibliography
\usepackage[backend = biber,
style = nature,
sorting = none
]{biblatex}
\def\printbibnumber{\hspace*{1.5em}%
\llap{\printtext[labelnumberwidth]{%
\printfield{prefixnumber}%
\printfield{labelnumber}%
}%
}%
}
\addtolength\hintscolumnwidthV{-1.75em}
\else
\usepackage[backend = biber,
style = authoryear,
sorting = none
]{biblatex}
\def\printbibnumber\relax
\fi
and then use the \printnumber macro before your \tldatecventryV.
The \hspace{1.5em} makes room for two-digit numbers.
Complete (working, I hope) example:
\documentclass[sans]{moderncv}
\moderncvstyle{classic}
\moderncvcolor{orange}
\usepackage[scale=0.75]{geometry}
\usepackage{moderntimeline}
\tlmaxdates{1888}{1929}
\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@Article{Jones1929,
author = {Jones, Grinnell and Dole, Malcolm},
title = {THE VISCOSITY OF AQUEOUS SOLUTIONS OF STRONG ELECTROLYTES},
journaltitle = {J. Am. Chem. Soc.},
date = {1929},
volume = {51},
number = {10},
pages = {2950--2964},
doi = {10.1021/ja01385a012}
}
@Article{Drude1894,
author = {Drude, P. and Nernst, W.},
title = {{\"U}ber Elektrostriktion durch freie Ionen},
journaltitle = {Z. Phys. Chem.},
date = {1894},
volume = {15},
pages = {79--85},
}
@Article{Hofmeister1888,
author = {Hofmeister, Franz},
title = {Zur Lehre von der Wirkung der Salze},
journaltitle = {Arch. Exp. Pathol. Pharmakol.},
date = {1888},
volume = {25},
number = {1},
pages = {1--30},
doi = {10.1007/BF01838161},
}
\end{filecontents*}
%-----------------------------------------------------------
\newif\ifnumericCVbibliography
\numericCVbibliographytrue % replace true with false to disable
\newlength{\hintscolumnwidthV}
\setlength\hintscolumnwidthV{\hintscolumnwidth}
\ifnumericCVbibliography
\usepackage[backend = biber,
style = nature,
sorting = none
]{biblatex}
\def\printbibnumber{\hspace*{1.5em}%
\llap{\printtext[labelnumberwidth]{%
\printfield{prefixnumber}%
\printfield{labelnumber}%
}%
}%
}
\addtolength\hintscolumnwidthV{-1.75em}
\else
\usepackage[backend = biber,
style = authoryear,
sorting = none
]{biblatex}
\def\printbibnumber\relax % do nothing
\fi
\addbibresource{\jobname.bib}
%-----------------------------------------------------------
\makeatletter
\newcommand*{\cventryV}[1][.25em]{}
% for numeric bibliography
\newcommand{\tldatecventryV}[2][color1]{%
\issincefalse
\tl@formatstartyear{#2}
\cventryV{\tikz[baseline=0pt]{
\useasboundingbox (2ex,0ex) rectangle (\hintscolumnwidthV,1ex);
\fill [\tl@runningcolor] (0,0)
rectangle (\hintscolumnwidthV,\tl@runningwidth);
\fill [#1] (0,0)
++(\tl@startfraction*\hintscolumnwidthV,0pt)
node [tl@singleyear] {#2}
node {$\bullet$};
}}}
\makeatother
% 'numeric' bibliography environment (from numeric.bbx)
\defbibenvironment{bibliography}
{\list
{\printbibnumber % here you see the macro in action
\tldatecventryV{%
\thefield{year} % actual year from bibitem
}}
{\setlength{\topsep}{0pt}% layout parameters based on moderncvstyleclassic.sty
\setlength{\labelwidth}{\hintscolumnwidth}%
\setlength{\labelsep}{\separatorcolumnwidth}%
\setlength{\itemsep}{\bibitemsep}%
\leftmargin\labelwidth%
\addtolength{\leftmargin}{-.35\labelsep}% <-- changed
\advance\leftmargin\labelsep
}%
\sloppy\clubpenalty4000\widowpenalty4000}
{\endlist}
{\item}
%-----------------------
\AtEveryBibitem{\clearfield{year}}
%-------------------------------------------------------------------------------
% reverse numbering of publications
%-------------------------------------------------------------------------------
% Count total number of entries in each refsection
\AtDataInput{%
\csnumgdef{entrycount:\therefsection}{%
\csuse{entrycount:\therefsection}+1}}
% Print the labelnumber as the total number of entries in the
% current refsection, minus the actual labelnumber, plus one
\DeclareFieldFormat{labelnumber}{\mkbibdesc{#1}}
\newrobustcmd*{\mkbibdesc}[1]{%
\number\numexpr\csuse{entrycount:\therefsection}+1-#1\relax}
%------------------- Personal Data for CV header -------------------------------
\name{Joan}{Doe}
%-------------------------------------------------------------------------------
\begin{document}
\makecvtitle
\nocite{*}
\printbibliography[type=article,title={Journal Publications}]
\end{document}
Best Answer
\defbibenvironmentpretty much takes the same arguments as\newenvironment. For the standard numeric styles the default bibliography environment is defined innumeric.bbx. You can adapt this definition to use the list layout parameters formoderncv'sthebibliographyenvironment. The following document takes the parameters frommoderncvstyleclassic.sty.