Separator "." in date data is no longer working

[pietrasagh]

Separator "." in date data (e.g. "2001.12.13") is no longer working . Other combinations of "/", " " and "," are parsed correctly (e.g. "2019 //// 10, ,,,, / 01" or "2019 11 01"). It seems that separator "-" can be only one and not combined with any other.
Problem may be due to some update in d3 or deeper in eslint. I noticed it on wikipedia Graph Extension which is using Vega 2.
I tested it on
in editor for Vega version Vega 5.15.0
and Vega 2 editor

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "width": 500,
  "height": 250,

  "data": [
    {
      "name": "traffic",
      "values": [
        {"date": "2020.01.01", "curr": 3764192, "prev": 3560276},
        {"date": "2019 ////  10, ,,,, / 01", "curr": 4292562, "prev": 4044655},
        {"date": "2019    11     01", "curr": 3892767, "prev": 3817267},
        {"date": "2019-12-01", "curr": 4320042, "prev": 3937790}
      ],
      "format": {
        "type": "json",
        "parse": {"date": "date"}
      },
      "transform": [
        {
          "type": "timeunit",
          "units": ["year", "month"],
          "field": "date"
        }
      ]
    }
  ],

  "scales": [
    {
      "name": "x",
      "type": "time",
      "range": "width",
      "padding": 24,
      "domain": {"data": "traffic", "field": "unit0"}
    },
    {
      "name": "y",
      "type": "linear",
      "range": "height",
      "nice": true,
      "zero": false,
      "domain": {"data": "traffic", "field": "curr"}
    }
  ],


  "axes": [
    {
      "orient": "bottom",
      "scale": "x",
      "format": "%b %Y"
          },
    {
      "orient": "left",
      "scale": "y",
      "grid": true

    }
  ],

  "marks": [
    {
      "type": "line",
      "aria": false,
      "from": {"data": "traffic"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "unit0"},
          "y": {"scale": "y", "field": "curr"},
          "stroke": {"value": "steelblue"},
          "strokeWidth": {"value": 3}
        }
      }
    }
  ]
}

[domoritz]

Vega uses standard browser date parsing and only dates in the standard formats are supported.

Vega 2 probably used datalib and may have used different date parsing ut I haven't checked.

[domoritz]

It would be awesome if you help update the graph extension to the latest Vega versions, btw.

[pietrasagh]

I checked example code with "." separator on mentioned mozilla website and it works.

const javaScriptRelease = Date.parse('04.12.1995');
console.log(javaScriptRelease);
// expected output: 818035920000

My js skills are on "Hello world" level. Unfortunate Mediawiki developers seems to be overloaded with more urgent issues. They started to work on it but got stucked. If you could help would be great. Please contact Yurik for details

[jheer]

Unfortunately, '04.12.1995' is simply not a universally valid date. I just tested and it works in Chrome, but not in Firefox. I don't believe this is a Vega-specific issue, but rather a consequence of different browsers supporting inconsistent formats for Date.parse. The solution is to change the input data to use a valid date string accepted by all major browsers.

[jheer]

Alternatively, you can specify the date format yourself as part of the Vega specification, as described here: https://vega.github.io/vega/docs/data/#format.

You can pass a format parameter like {"myDateField": "date:'%m.%d.%Y'"} to specify a custom date format.
I don't recall offhand but I believe we supported this in Vega 2 as well.

[pietrasagh]

This could be best solution for me. I will check if it works.
Thanks!