Kendo-angular: selectedKeys should have NOT mutate array

[montella1507]

SelectedKeys of Grid and another components violates unidirectional dataflow - what is even worse it violates least surprise principle.

Input properties shoudl be never mutated, because it leads to several issues (problem with memoization, expressionhasbeenchangedaftercheck, etc..) and it is door closer - for example, it is not easy to use any state-management system. You cannot do something like

[selectedKeys]="gridStateFromStore.selections"
(selectionChange)="store.dispatch(...)"

please reconsider your implementation.

Mutating inputs is bad habit and should be avoided as much as possible.

[tsvetomir]

Seems like a valid concern. We emit selectedKeysChange so mutating the array is not expected.

It also applies to the kendoGridExpandDetailsBy, kendoTreeViewExpandable and kendoTreeViewSelectable.

[christianacca]

IF this is changed, then this must be flagged as a breaking change please!

[montella1507]

To be honest it must be changed, because this way, the behavior is considered as ,,undefined" in angular (mutating inputs).

Kendo had several issues with mutanting inputs (hello grid filters), however, it was unintentionally there (bug).

[christianacca]

@montella1507 makes sense. Just asking that the kendo team to mark this as a breaking change as it is

[Raisolution]

Thank you for raising the concern around this item. We are still in the process of evaluating the most appropriate implementation and will try to align the same behavior between the Grid and TreeList components. If the current behavior of any of those components is changed, it will be marked as a breaking change accordingly.