improved.js

var charts = ["#drug", "#clinical", "#mri", "#disease", "#gd", "#relapses"].map(function (chart) {
  return datachart.compositeChart(chart);
});
charts.push(datachart.barChart("#monthly-chart"));

var svg = element.children('svg');
function compile () { $compile(svg)(scope); };

charts.map(function (chart) { chart.on('postRender', compile); });

original.js

var chartDrug = datachart.compositeChart("#drug");
var chartClinical = datachart.compositeChart("#clinical");
var chartMRI = datachart.compositeChart("#mri");
var chartDisease = datachart.compositeChart("#disease");
var moveChart = datachart.barChart("#monthly-chart");
var chartGD = datachart.compositeChart("#gd");
var chartRelapses = datachart.compositeChart("#relapses");

chartDisease.on("postRender",function () {
  $compile(element.children('svg'))(scope)
});
chartGD.on("postRender",function () {
  $compile(element.children('svg'))(scope)
});
chartMRI.on("postRender",function () {
  $compile(element.children('svg'))(scope)
});
chartClinica62l.on("postRender",function () {
  $compile(element.children('svg'))(scope)
});