How put halo around text using the contour package as suggested in this answer in many nodes by defining a style?
MWE:
\documentclass[tikz]{standalone}
\usepackage[outline]{contour} %halo around text
%https://tex.stackexchange.com/questions/18472/tikz-halo-around-text
\contourlength{1.2pt}
\usetikzlibrary{patterns}
\begin{document}
\begin{tikzpicture}[halo text node/.style={circle, draw, pattern=north east lines}]
\node [halo text node] {\contour{white}A};
\end{tikzpicture}
\end{document}
Result:
What I want is to include an option for the tikzpicture in a form similar to halo text node/.style{...,text=\contour{white}} instead of using \contour{white}{...} inside every node.

