Hi, 

Why there are no examples of Boolean and date grouping in the documentation? these are common data types and should be supported without overriding the default grid behavior. In my example date is displayed but not formatted and Boolean is missing https://stackblitz.com/edit/react-7exwjp?file=app%2Fmain.jsx . 

Hello, Matej,

The main reason for this is that we show the data in those rows as we receive it.

I can suggest checking this issue/discussion here on more details why and how we are processing the group rows:

https://github.com/telerik/kendo-react/issues/53

Also, we have an idea for a type property of a column, which helps us know the specific type and allows us to make automatic formating based on that:

https://github.com/telerik/kendo-react/issues/414

Regards,
Stefan
Progress Telerik

So only "text" cells are working properly. No boolean or date/number because "format" and "locale" .

 "It is easy for the user to decide if he wants to format them before passing down to the grid. (more over he could already do that)"  I do not understand this. I am not formatting ma data because I am using column "format" prop and your IntlProvider. I also can not convert everything to formatted strings because IntlProvider and format will be useless and all of my custom cells will stop working.  Only solution I see there is your "cellRender" but clone and override the cell is not the most future proof solution. 

1. So I have to create cellRender, connect it to IntlProvider, clone the cell, remove all children except the arrow td.props.children.props.children[0] and hope you will never change the layout, read props.dataItem.value, check it for value type, format it and apply this to every grid. Where can I find the column "format" value in the cellRender? https://stackblitz.com/edit/react-7exwjp-c6atam?file=app%2Fmain.jsx

2. Is there an easier solution I overlooked? 

Hello, Matej,

I completely understand your point and I can agree that we can provide an easier way to handle these cases. One of the options is to add the type to the column based on the issue that I linked. This will allow us to format the groups as well as we will already know the specific type.

As for changing the rendering, we change the rendering in very very few cases and it will be either to fix an issue or a breaking change that will be noted in the release notes.

As for the format in the cellRender I can suggest having a global const for the format and to use it inside the Column configuration and on the cellRender:

https://stackblitz.com/edit/react-7exwjp-cveckj?file=app%2Fmain.jsx

Regards,
Stefan
Progress Telerik

Kendo grids require a lot of custom code (to enable selecting, sorting, filtering, expanding) but you are not passing important props to custom components (also had a problem with missing prop here https://www.telerik.com/forums/kendo-grid-custom-cell-with-row-selection) because you are expecting that all the code is written in a single file and all functions/methods have access to everything. This is not true. I am sure that I am not the only one who have a shared "BasicGrid" component with selecting/sorting/filtering/grouping/expanding... implemented and reusing it across the app. In this case custom cell functions or column configs can be in a completely different part of the application than the grid. One example:

My point is that if you expect us to create custom code we should have all necessary data. Now we have to extract the data, save it to redux or context, share it between components, "watch" for data change and update shared state. This is adding unnecessary complexity.