Need to accept empty data

Errors occurred when I tried to use empty data object to initialize a chart instance.

  const chart = new frappe.Chart('.panel .chart', {
    data: {},
    type: 'line',
    height: 320,
    colors: ['#0294FF'],
  })

This caused an Uncaught TypeError:

frappe-charts.min.iife.js:1 Uncaught TypeError: Cannot read property 'map' of undefined
    at Ct (frappe-charts.min.iife.js:1)
    at i.value (frappe-charts.min.iife.js:1)
    at i.e (frappe-charts.min.iife.js:1)
    at new i (frappe-charts.min.iife.js:1)
    at Tt (frappe-charts.min.iife.js:1)
    at new t (frappe-charts.min.iife.js:1)
    at HTMLDocument.<anonymous> (stats-overview.js:20)
    at l (jquery.js:2)
    at Object.fireWith [as resolveWith] (jquery.js:2)
    at Function.ready (jquery.js:2)

Seems frappe tried to call map function of datasets or labels. But I only need to create an empty chart at that time, and update data on future user events.

I tried to use this as init data

{
  labels: [],
  datasets: [],
}

and got a lot of SVG errors which blocked the future data updatings.

Error: <g> attribute transform: Trailing garbage, "translate(0, undefined)".

It’s weird that

{
  labels: [''],
  datasets: [{
    values: [0],
  }],
}

also cause some errors such as

frappe-charts.min.iife.js:1 Error: <path> attribute d: Unexpected end of attribute. Expected number, "M".

and

Error: <circle> attribute cy: Expected length, "undefined".

but without blocking future updatings.

Seems it only works fine with two or more data points.

User-Agent:

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36

[blueabysm]

The when creating charts it is necessary to provide the labels at least. With the labels in place the Charts will automatically fill in the value 0 as default for the missing values.

So a config like the following will work without any errors.

data: {
	labels: ['Monday, 'Tuesday', 'Wednesday', 'Thursday', 'Friday'],
	datasets: [],
}

I hope this answers your question.

Thanks a lot for your help. But actually for me, it’s not a perfect solution 😂. I don’t know any of the labels until the server responds them via an xhr (for example last 30 days as labels). Better if frappe could draw an empty chart without any data or labels provided at initialization. Now I manually set two labels as a walkaround, it seems a little bit strange showing two unrelated zero data points on every refresh before real data loaded.

[scmmishra]

The when creating charts it is necessary to provide the labels at least. With the labels in place the Charts will automatically fill in the value 0 as default for the missing values.

So a config like the following will work without any errors.

data: {
	labels: ['Monday, 'Tuesday', 'Wednesday', 'Thursday', 'Friday'],
	datasets: [],
}

I hope this answers your question.