In case of line / spline chart, by default line will be broken when datapoint with null value is present. You can connect the non-null values directly by setting connectNullData property to true – which draws a dashed line to connect non-null datapoints. The type of this line can be changed by setting nullDataLineDashType property. Please refer to the code-snippet below.
...
data: [{
...
type: "line",
connectNullData: true,
nullDataLineDashType: "solid",
...
}]
...
Please take a look at this updated JSFiddle for complete code.
—
Vishwas R
Team CanvasJS