[Bug]: DataGrid : DatePicker Column isn't compatible with DisplayFormat

[David-Moreira]

@stsrki

I Remember now why we had a separate DateDisplayFormat.
The DisplayFormat isn't really compatible with the DatePicker format style. It seems to use a string.format

DisplayFormat="{0:dd.MM.yyyy}"
UI

DatePicker

DisplayFormat="dd.MM.yyyy"

UI

DatePicker

What do you think, should we revert back?

[stsrki]

Not sure. DisplayFormat is used for display in a non-edit mode. Only when the row is edited that the DatePicker is shown. Right? So then it shouldn't affect it?

[David-Moreira]

I don-t understand your question. I just showed you the differences with the screenshots. Cell Display vs DatePicker input.

[stsrki]

I don-t understand your question. I just showed you the differences with the screenshots. Cell Display vs DatePicker input.

Sorry, I was looking at the wrong date input in the image. Yeah, I see the problem now.

Whichever path we take will be a breaking change/behavior for our users. If we tell them to now write "dd.MM.yyyy" instead of "{0:dd.MM.yyyy}" as previously, or if they replace DisplayFormat with DateDisplayFormat it is essentially the same. They need to change their code.

I'm more open to telling them to do "dd.MM.yyyy" instead of "{0:dd.MM.yyyy}" as that will not introduce any new API.

[stsrki]

Dumb idea.. What if we parse and convert "{0:dd.MM.yyyy}" to "dd.MM.yyyy"?

[stsrki]

ChatGPT 😅

public static string ConvertToSimpleDateFormat(string inputFormat)
{
     var match = Regex.Match(inputFormat, @"\{0:(.+?)\}");
    if (match.Success)
    {
         return match.Groups[1].Value;
    }  
 
    return inputFormat;
}

[David-Moreira]

Well first of all why are we even using this type of format "{0:}" ? Was there a special reason for it? Seems weird to define it like this honestly. I'd expect it to work just like : "dd.MM.yyyy".
So if there's no special reason, we could consider the change in order to make it more clear. As a user I would expect "dd.MM.yyyy" instead of "{0:dd.MM.yyyy}".

Now, we could wait for 2.0 to make that breaking change, and just try to infer the proper format for DatePicker as you mention.

[stsrki]

Well first of all why are we even using this type of format "{0:}" ? Was there a special reason for it? Seems weird to define it like this honestly. I'd expect it to work just like : "dd.MM.yyyy".

I have no idea TBH. It was so long ago that I really don't know the reason by now.

[David-Moreira]

ChatGPT 😅

public static string ConvertToSimpleDateFormat(string inputFormat)
{
var match = Regex.Match(inputFormat, @"{0:(.+?)}");
if (match.Success)
{
return match.Groups[1].Value;
}

return inputFormat;

}

Lol, don't let your "brain rot" by depending on it too much. StartsWith and EndsWith works equally well in this case. Probably more readable even.
But yea for some stuff it's easy to just not waste time thinking and jump in chatgpt.

[stsrki]

My brain is already rot from a lack of sleep from looking at my 1 year old 😅