Null date column

[Alison]

Hi

I've done some searching but can't find a solution to this.

Essentially, I have a settlement date column in my grid, however, this column can be null because the settlement date may not have been set yet.

How do I show a date if there's a date entered, blank string if there's no date entered yet?

I'm using JSON data in my datasource. I couldn't find a way to bring NULL dates in JSON so I'm currently bringing in the NULL dates as 01/01/0001 (which, by searching, seems to be the earliest date in JSON).

My column at the moment is:

columns: [

{ field: "SettlementDate", width: "150px", title: "Settlement Date", format: "{0:d/MM/yyyy}", filterable: { ui: "datetimepicker" } }

]

I want to allow batch editing of the grid.

Any suggestions or direction from someone who overcame a similar problem would be appreciated.

Thanks, Alison

[Alexander Valchev]

Hi Alison,

By default the grid will display empty string if the field has a null value. If in your case the data is not null, you may use a template with JavaScript expression to display a value according to your requirements. For example:

{ field: "date", template: "#= <condition> ? kendo.toString(date, 'd/MM/yyyy') : " " #" }

Even though that the template will do the job, I recommend you to revise your server side implementation and return null instead of "01/01/0001". In this way you would be able to get the described behaviour out of the box.

Regards,
Alexander Valchev
the Telerik team

[Alison]

Thanks Alexander

I managed to get the JSON to pass through a null.

So, the .asmx file ended up...

Public Class cDetail

    Public SettlementDate As DateTime?

End Class

<WebMethod> _

<ScriptMethod(ResponseFormat:=ResponseFormat.Json, UseHttpGet:=False)> _

Public Function getDetail() As cDetail()

    Dim items As New List(Of cDetail)

    .... omitted

    Using oConn As New SqlConnection(ConfigurationManager.ConnectionStrings("conn").ToString())

        .... omitted

        Dim item As New cDetail()

        .... omitted

        Dim dteTemp As Date

        If (Date.TryParse(dr.Item("SettlementDate").ToString(), dteTemp) = True) Then

            item.SettlementDate = dteTemp

        End If

        .... omitted

    End Using

 

    Return items.ToArray()

End Function

I guess there's a lesson in there to not keep trying to get something to work last thing on a Friday - you tend to miss the obvious :).

Regards, Alison

[Victor]

Is there a function that can encapsulate this logic "#= <condition> ? kendo.toString(date, 'd/MM/yyyy') : " " #"?  I have multiple values that need to check if it is null and it just seems that this logic can be called once and reused. 

[Dimiter Topalov]

Hi Victor,

The columns.template option can be set to a function that takes the dataItem as an argument and returns the string to be rendered in the respective Grid cell, e.g.:

http://dojo.telerik.com/EfIcU

I hope this helps.

Regards,
Dimiter Topalov
Telerik by Progress

[Victor]

Thanks for the example.

How can I get this same function to work in a Custom Template in an MVC Kendo Grid?  Here is a snippet of code.

 

<div class='col-lg-4 col-md-4 col-sm-4'>
<label class="tab-strip-label">Lot</label>
<span class="tab-strip-span">#= LotNumber ==null ? "" : LotNumber #</span>
</div>

I want to do something like this and get an empty string.

<div class='col-lg-4 col-md-4 col-sm-4'>
<label class="tab-strip-label">Lot</label>
<span class="tab-strip-span">#= ToString(LotNumber) #</span>
</div>

[Boyan Dimitrov]

Hello Victor,

I believe that what you are looking for is How to Apply Conditional Logic in Column Client Templates?. 

Regards,
Boyan Dimitrov
Telerik by Progress

[Victor]

I am looking to use a function in javascript similar to this c# method.

public string GetValue(string e)
{
            return (e == null) ? "" : e;
}

And in my client template I want to call it like this.

<span class="tab-strip-span">#= GetValue(LotNumber) #</span>

Instead of like this

<span class="tab-strip-span">#= LotNumber ==null ? "" : LotNumber #</span>

 

 

[Boyan Dimitrov]

Hello Victor,

Please refer to the Handle External Templates and Expressions and specifically take a look at the second example. 

Regards,
Boyan Dimitrov
Telerik by Progress