New datases do not shows Chart js - chart.js

Question

Using line chart js.
Need to make checkbox which show/hide datasets
I made something like this:
lineChartData = {
labels : ["01.01.2015","012.01.2015","03.01.2015","04.01.2015","05.01.2015","06.01.2015","07.01.2015"],
datasets : dataSets
};
where dataSets is array of dataset objects, and when checkbox changed i do the next:
if($(this).prop('checked')){
myNewChart.datasets[datasetId] = dataSets[datasetId];
}
else{
myNewChart.datasets[datasetId]= {};
}
myNewChart.update();
myNewChart.datasets[datasetId]= {}; Works and delete line on graph, but adding dataset back not showing the line, however it added in myNewChart.datasets array.

Answer 1

Just destroy and redraw the chart. While Chart.js does support adding and removing line points - it is by label (and not by dataset - which is what you want)
Your problem was that you were emptying out the actual dataset objects - if you link it to a copy of the dataset everything works.
Here is your updated change handler
$('input:checkbox').change(function () {
var chartId = $(this).attr('data-chart-id');
var datasetId = $(this).attr('data-data-set');
dataSets[datasetId].hide = !$(this).prop('checked')
lineChartData.datasets = []
dataSets.forEach(function (dataset) {
// create a copy of the dataset to modify (if required) and put into the chart dataset array
var copy = jQuery.extend(true, {}, dataset)
if (dataset.hide)
copy.data = []
lineChartData.datasets.push(copy)
})
// create the graph from scratch
myNewChart.destroy()
myNewChart = new Chart(ctx).Line(lineChartData, chartOpt);
});
Fiddle - http://jsfiddle.net/6qdm7nwu/