EDIT: Added Title clickable (1. just the title cickable and 2. the whole reference clickable)
1. Just the Title reference clickable
You can redefine the title macro and add the \href to the title using the DeclareFieldFormat. I edited the default definitions in the biblatex.def file.
\DeclareFieldFormat{title}{\myhref{\mkbibemph{#1}}}
\DeclareFieldFormat
[article,inbook,incollection,inproceedings,patent,thesis,unpublished]
{title}{\myhref{\mkbibquote{#1\isdot}}}
And the macros are:
\newcommand{\doiorurl}{%
\iffieldundef{doi}
{\iffieldundef{url}
{}
{\strfield{url}}}
{http://dx.doi.org/\strfield{doi}}%
}
\newcommand{\myhref}[1]{%
\ifboolexpr{%
test {\ifhyperref}
and
not test {\iftoggle{bbx:url}}
and
not test {\iftoggle{bbx:doi}}
}
{\href{\doiorurl}{#1}}
{#1}%
}
MWE
\documentclass{article}
\usepackage[backend=biber,style=numeric-comp,sorting=none,%
isbn=false,url=false,doi=false,firstinits=true]{biblatex}
\usepackage{filecontents}
\usepackage{hyperref}
\begin{filecontents}{\jobname.bib}
@Article{usingdoi,
author={The First Author},
title={Using DOI},
year={2014},
journal={J. Med. Sc.},
publisher={Springer},
doi={10.1103/PhysRevLett.77.3865},
pages={1-2},
}
@Article{usingurl,
author={The Other Authors},
title={Using URL},
number={2},
year={1998},
month={4},
journal={ACM Trans. Inf. Sys.},
publisher={Springer},
volume={16},
pages={127-160},
url={https://www.google.com}
}
@Article{nodoiurl,
author={The Author},
title={Neither doi or url},
number={2},
year={1998},
month={4},
journal={ACM Trans. Inf. Sys.},
publisher={Springer},
volume={16},
pages={127-160},
}
\end{filecontents}
\newcommand{\doiorurl}{%
\iffieldundef{doi}
{\iffieldundef{url}
{}
{\strfield{url}}}
{http://dx.doi.org/\strfield{doi}}%
}
\newcommand{\myhref}[1]{%
\ifboolexpr{%
test {\ifhyperref}
and
not test {\iftoggle{bbx:url}}
and
not test {\iftoggle{bbx:doi}}
}
{\href{\doiorurl}{#1}}
{#1}%
}
\DeclareFieldFormat{title}{\myhref{\mkbibemph{#1}}}
\DeclareFieldFormat
[article,inbook,incollection,inproceedings,patent,thesis,unpublished]
{title}{\myhref{\mkbibquote{#1\isdot}}}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}%XXIII

2. The whole reference clickable
I found a way that allow to make a reference clickable (The whole text of the reference is clickable)
For this I Modified the definition of DeclareBibliographyDriver to add a \href to the full reference.
This is necessary before biblatex load the bibliography style.
By default, before load the style files, biblatex try load the file biblatex-dm.cfg (biblatex custom data model), then it is possible modify the DeclareBibliographyDriver using this file.
I created the file (biblatex-dm.cfg) in the work directory with the content:
\newcommand{\doiorurl}{%
\iffieldundef{doi}
{\iffieldundef{url}
{}
{\strfield{url}}}
{http://dx.doi.org/\strfield{doi}}%
}
\newcommand{\bibdrivercontent}[1]{%
\ifboolexpr{%
test {\ifhyperref}
and
not test {\iftoggle{bbx:url}}
and
not test {\iftoggle{bbx:doi}}
}
{\href{\doiorurl}{#1}}
{#1}%
}
\let\OldDeclareBibliographyDriver\DeclareBibliographyDriver
\renewcommand{\DeclareBibliographyDriver}[2]{\OldDeclareBibliographyDriver{#1}{\bibdrivercontent{#2}}}
This code use \href only if hyperref is loaded and doi and url options are false.
The MWE:
\documentclass{article}
\usepackage[backend=biber,style=numeric-comp,sorting=none,%
isbn=false,url=false,doi=false,firstinits=true]{biblatex}
\usepackage{filecontents}
\usepackage{hyperref}
\begin{filecontents}{\jobname.bib}
@Article{usingdoi,
author={The First Author},
title={Using DOI},
year={2014},
journal={J. Med. Sc.},
publisher={Springer},
doi={10.1007/0000-0xz},
pages={1-2},
}
@Article{usingurl,
author={The Other Authors},
title={Using URL},
number={2},
year={1998},
month={4},
journal={ACM Trans. Inf. Sys.},
publisher={Springer},
volume={16},
pages={127-160},
url={https://www.google.com}
}
@Article{nodoiurl,
author={The Author},
title={Neither doi or url},
number={2},
year={1998},
month={4},
journal={ACM Trans. Inf. Sys.},
publisher={Springer},
volume={16},
pages={127-160},
}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}
And the result:

eprintandeprinttype? – cfr Oct 13 '14 at 23:13urlanddoiand only print the wordsurlordoiwith the hyperlink to the download location (And usingdoi=trueandurl=true, of course). – Carlos Lanziano Oct 13 '14 at 23:48