chart.js-php.js

// Will be filled with canvas
var ChartJSPHP = new Array();

// You must call this function after document.ready
function loadChartJsPhp() {
	// Getting all chart.js canvas
	var elements = document.querySelectorAll("[data-chartjs]");

    console.log(elements);

	// Looping every canvas
	for (var i in elements)
	{
		// Escaping length and item in the loop
		if (i === 'length' || i === 'item') {
			continue;
		}
		var canvas = elements[i];
		var id = canvas.id;

		// Getting ctx from canvas
		var ctx = canvas.getContext('2d');

		// Getting values in data attributes
		var htmldata = canvas.dataset;
		var data = JSON.parse(htmldata.data);
		var type = htmldata.chartjs;

		// Creating chart and saving for later use
		ChartJSPHP[id] = new Chart(ctx)[type](data);
	}
};