Doing math on aggregates

[Brian Vallelunga]

I need a couple of my aggregate fields to be calculated based on the aggregates of other columns. Is this possible?

For example, if I have the following fields:

Revenue, Cost, Margin (Revenue - Cost), Margin % (Margin / Revenue)

For aggregating these fields, sum works fine on Revenue, Cost, and Margin. However, if I want to find the total Margin %, I need to do: SUM(Margin) / SUM(Revenue). Is there a way to do this with the DataSource?

[Alexander Valchev]

Hello Brian,

I am afraid that the dataSource currently does not support such functionality out of the box. It is possible to achieve it via custom code in the template function - for example:

{ field: "Revenue", title: "Revenue", footerTemplate: "Results: #= doMath() #"}
//...

function doMath() {
    var ds = $("#grid").data("kendoGrid").dataSource;
    var aggregates = ds.aggregates();
    var margin = aggregates.Revenue.sum - aggregates.Cost.sum;
    //...
    return "your result string";
}

This approach will work with pre-set dataSource aggregates though (like in this example), e.g. when groupable is not enabled.

Greetings,
Alexander Valchev
the Telerik team

[Brian Vallelunga]

That works just fine, thanks.

[Nathan]

I'm trying to achieve the same functionality.  Would you please post a complete example.  The code for the grid and the script for doing the math on the aggregate.  Also, please don't point me to the example that you mentioned in your post.  It doesn't do custom functions on the aggregate.

[Alexander Valchev]

Hello Nathan,

Please check this sample page: http://trykendoui.telerik.com/IdEd/2
Inside you will find an example that demonstrates how to do math with aggregates, in this particular case the Grid displays half of the total products count.

Regards,
Alexander Valchev
Telerik

 

 

[Nathan]

Hi Alexander

This is no longer an issue for me.  Thank you for providing an example.

[Rajesh]

Hello I'm using the example provided however I have requirement to show custom aggragated values on groupfooter as well. Can you show me how it can be achieved in below example?
http://dojo.telerik.com/IdEd/10

(Group half Count) value for each group.

[Alexander Valchev]

Hello Rajesh,

To me it looks like that the example you provided is working and is displaying the Group half Count value for each group. I added the count aggregate to the group footer template and verified that the displayed values are correct. Please see the attached screen shot.

Am I missing something?

Regards,
Alexander Valchev
Telerik

 

 

[Vachara]

Hi,

How does this example work with AngularJS?
Can I add a custom aggregate function to $scope and use it in footer template like your "doMath()" function?

Thank you.

[Alexander Valchev]

Hello Vachara,

The groupFooterTemplate can also accept a function. Please try to directly assign a function to it in the Grid configuration object.

{ field: "Revenue", title: "Revenue", footerTemplate: $scope.footerTemplateConstructor }

Regards,
Alexander Valchev
Telerik

 

 

[Vachara]

Hi Alexander,

I could see that we can use $scope to directly return a template string.
But my point is, can we use $scope function inside said template? Something like this

// In an AngularJS controller...
{ field: "Revenue", title: "Revenue", footerTemplate: "Results: #= $scope.doMath() #"}

//...

$scope.doMath() {
    // Whatever calculation regarding the grid data
    return "your result string";
}

Thank you.

[Alexander Valchev]

Hello Vachara,

This is not possible. Templates are executed in the global window scope, $scope is not available in the global window scope.

Regards,
Alexander Valchev
Telerik

 

 

[Vachara]

Thank you.