How to set locale (globally) in Vega - d3.js

Question

I would like to configure the locale for a visualization in Vega. I need a German number format, which means that I need a comma (,) as decimal separator. Without any configuration in Vega, a decimal point (.) is used as separator.
Here is a complete working example which shows a simple bar chart. As you can see in the image below, I want to format the numbers on the y-Axis and the values inside the bars with two decimal places.
How can I set a specific locale (e.g. German) either globally for the whole visualization or for each number format separately? (I would prefer a global setting.)
(Note: You can use the Vega Editor to paste and try out my bar chart example.)
{
"width": 600,
"height": 300,
"padding": {"top": 10, "left": 35, "bottom": 30, "right": 10},
"data": [
{
"name": "table",
"values": [
{"x": 1, "y": 0.5},
{"x": 2, "y": 0.8},
{"x": 3, "y": 0.3},
{"x": 4, "y": 0.6}
]
}
],
"scales": [
{
"name": "x",
"type": "ordinal",
"range": "width",
"domain": {"data": "table", "field": "x"},
"padding": 0.1
},
{
"name": "y",
"type": "linear",
"range": "height",
"domain": {"data": "table", "field": "y"}
}
],
"axes": [
{"type": "x", "scale": "x"},
{"type": "y", "scale": "y", "format": ".2f"}
],
"marks": [
{
"type": "rect",
"from": {"data": "table"},
"properties": {
"enter": {
"x": {"scale": "x", "field": "x"},
"width": {"scale": "x", "band": true, "offset": -1},
"y": {"scale": "y", "field": "y"},
"y2": {"scale": "y", "value": 0}
},
"update": {
"fill": {"value": "steelblue"}
}
}
},
{
"type": "text",
"from": {"mark": "bars"},
"properties": {
"enter": {
"y": {"field": "y", "offset": 10},
"x": {"field": "x"},
"dx": {"field": "width", "mult": 0.6},
"fill": {"value": "white"},
"align": {"value": "right"},
"baseline": {"value": "middle"},
"text": {"template": "{{datum.datum.y | number:'.2f'}}"}
}
}
}
]
}

Answer 1

I found a pull request in the Vega GitHub repository which allows to set the number and time locale. Also runtime changes are supported.
Example for changing the number format to German:
vg.util.format.numberLocale({
decimal: ",",
thousands: ".",
grouping: [3],
currency: ["", "\xa0€"]
});
Example for changing the time format to German:
vg.util.format.timeLocale({
dateTime: "%A, der %e. %B %Y, %X",
date: "%d.%m.%Y",
time: "%H:%M:%S",
periods: ["AM", "PM"], // unused
days: ["Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samstag"],
shortDays: ["So", "Mo", "Di", "Mi", "Do", "Fr", "Sa"],
months: ["Januar", "Februar", "März", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"],
shortMonths: ["Jan", "Feb", "Mrz", "Apr", "Mai", "Jun", "Jul", "Aug", "Sep", "Okt", "Nov", "Dez"]
});