dynamic-barchart-extract-color-fm-table-data-9000[5star].tex

% Select color of a bar plot from table value
% https://tex.stackexchange.com/questions/493962/select-color-of-a-bar-plot-from-table-value

\documentclass{article}
\usepackage{pgfplots, pgfplotstable}
\pgfplotsset{compat=1.16}
\usetikzlibrary{calc}
\usepackage[utf8]{inputenc}

% tight page
\usepackage[active,tightpage]{preview}  % set tight page
\PreviewEnvironment{tikzpicture}        % preview tikz
\setlength\PreviewBorder{20pt}%         % gap around plot

\pgfkeys{/pgf/shapes/xbar/height/.initial=10cm,/pgf/shapes/xbar/width/.initial=6pt}

\pgfdeclareplotmark{xbar}{%
    \pgfpathrectangle{\pgfpoint{0pt}{-.5*\pgfkeysvalueof{/pgf/shapes/xbar/width}}{0pt}}{%
    \pgfpoint{-\pgfkeysvalueof{/pgf/shapes/xbar/height}}{\pgfkeysvalueof{/pgf/shapes/xbar/width}}}
    \pgfusepath{stroke,fill}}

\begin{document}

\pgfplotstableread[col sep=comma]{
	label, startyear, endyear, color, years  
	Washington, 1789, 1797, black!50, 8
	Adams, 1797, 1801, red!30, 4
	Jefferson, 1801, 1809, green!50, 8
	Madison, 1801, 1809, brown!50, 8
}\loadedtable

% sort by startyear
\pgfplotstablesort[sort key=startyear]\sortedtable\loadedtable

\begin{tikzpicture}
	\begin{axis}[
%		xmin=1785, 
%		xmax=1810, 
		height=4cm,
		/pgf/shapes/xbar/width=0.2cm,
	  	axis lines=left,
	  	width=\textwidth, 
	  	enlarge y limits={abs=0.5},
	  	ytick=\empty,
	  	scatter/@pre marker code/.code={
		  \pgfplotstablegetelem{\coordindex}{color}\of{\sortedtable}
		  \edef\mycolor{\pgfplotsretval}
		  \pgfplotstablegetelem{\coordindex}{startyear}\of{\sortedtable}
		  \edef\startyear{\pgfplotsretval}
		  \pgfplotstablegetelem{\coordindex}{endyear}\of{\sortedtable}
		  \edef\endyear{\pgfplotsretval}
		  \pgfplotstablegetelem{\coordindex}{years}\of{\sortedtable}
			\edef\years{\pgfplotsretval}		  
%		  \pgfmathsetmacro{\myheight}{(\endyear-\startyear)*\xunit} % height
		  \pgfmathsetmacro{\myheight}{(\years)*\xunit} % height
		  \scope[fill=\mycolor,/pgf/shapes/xbar/height=\myheight pt] },
	  legend style={at={(1,1.5)}}
	]
	
	\addplot [
		xbar , 
%		draw=none, 
		forget plot] table [col sep=comma,x=startyear, y expr=-\coordindex]{\sortedtable};
	\path let \p1=($(1786,0)-(1785,0)$) in \pgfextra{\xdef\xunit{\x1}}; % measure x unit
	
	\addplot[
		only marks, 
		scatter, 
		mark=xbar,
	   	nodes near coords*, 
	   	forget plot,
		nodes near coords align={anchor=west},
		point meta=explicit symbolic, 
		every node near coord/.append style={black}]  
	 		table[
	 			col sep=comma, 
	 			y expr=-\coordindex, 
	 			x expr=\thisrow{endyear}, 
	 			meta=label]{\sortedtable};
	 
	 % create object NumRows that we will use in foreach
	 \pgfplotstablegetrowsof{\sortedtable} 
	 \pgfmathtruncatemacro{\NumRows}{\pgfplotsretval-1} 

%		adds a colored legend	 
%	 \pgfplotsinvokeforeach{0,...,\NumRows}{
%		\pgfplotstablegetelem{#1}{color}\of{\sortedtable}
%		\edef\mycolor{\pgfplotsretval}
%		\pgfplotstablegetelem{#1}{label}\of{\sortedtable}
%		\edef\mylabel{\pgfplotsretval}
%		\edef\temp{\noexpand\addlegendimage{area legend,fill=\mycolor}
%		\noexpand\addlegendentry{\mylabel}}
%		\temp
%	 }
	\end{axis}
\end{tikzpicture}
\end{document}