Chart.js multiTooltip labels

I'm trying to get charts.js to display the label name from each dataset in the tooltip.

My code:

var barChartData = {
	labels : ["January","February","March","April","May","June","July"],
	datasets : [
	
		{
		    label: "Bob",
			fillColor : "rgba(88,196,246,0.5)",
			strokeColor : "rgba(88,196,246,0.8)",
			highlightFill: "rgba(88,196,246,0.75)",
			highlightStroke: "rgba(88,196,246,1)",
			data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
		},
		{
		    label: "Tina",
			fillColor : "rgba(74,211,97,0.5)",
			strokeColor : "rgba(74,211,97,0.8)",
			highlightFill : "rgba(74,211,97,0.75)",
			highlightStroke : "rgba(74,211,97,1)",
			data : [randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor(),randomScalingFactor()]
		}
		
	]
}

var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx).Line(barChartData, {
	responsive : true,
	animation: true,
	barValueSpacing : 5,
	barDatasetSpacing : 1,
	tooltipFillColor: "rgba(0,0,0,0.8)",				
	multiTooltipTemplate: "<%= label %> - <%= value %>"
			
});

With my above code the tooltip when hovering above "January" displays:

January
January - xx
January - xx

Any ideas how I can get it to display the following?

January
Bob - xx
Tina - xx

Change

window.myBar = new Chart(ctx).Line(barChartData, {
   responsive : true,
   animation: true,
   barValueSpacing : 5,
   barDatasetSpacing : 1,
   tooltipFillColor: "rgba(0,0,0,0.8)",                
   multiTooltipTemplate: "<%= label %> - <%= value %>"
});

to:

window.myBar = new Chart(ctx).Line(barChartData, {
   responsive : true,
   animation: true,
   barValueSpacing : 5,
   barDatasetSpacing : 1,
   tooltipFillColor: "rgba(0,0,0,0.8)",                
   multiTooltipTemplate: "<%= datasetLabel %> - <%= value %>"
});
   

The change is to the last line

multiTooltipTemplate: "<%= datasetLabel %> - <%= value %>"

datasetLabel gets the value of the label from the dataset objects (in this case 'Bob' and 'Tina'), whereas label gets the caption printed on the x-axis (part of the labels array)

want to update the answer, because I was searching for a long time.

You can now change the tooltips settings inside the options. See Docu: http://www.chartjs.org/docs/#chart-configuration-tooltip-configuration

As for the asked question, to show all X data.

window.myBar = new Chart(ctx).Line(barChartData, {
  tooltips: {
   mode: 'label'
 }           
});

Cheers Hannes

As I answered here, you can give multiTooltipTemplate a function. Put a breakpoint inside that function with 'debugger', and explore the given object for all the properties you'd like. Then construct a string to be displayed in your tooltip:

multiTooltipTemplate: function(v) {debugger; return someManipulation(v);}
tooltipTemplate: function(v) {return someOtherManipulation(v);}

Similar to the answer by Hannes but the documentation has been updated since then - There are various options now and the link he provided no longer goes anywhere as that option is deprecated.

I'm adding a new answer as it took me a while to find.

This is x mode - displays multiple dataset info in tooltip based on x axis

var chart = new Chart(ctx, {
    type: 'line',
    data: data,
    options: {
        tooltips: {
            mode: 'x'
        }
    }
})

http://www.chartjs.org/docs/latest/general/interactions/modes.html#x

There is also 'y' mode. Label mode is now deprecated.

You can also use 'point', 'index' and 'nearest' mode.