Trigger change event for select element

[Robelind]

I'm trying to trigger the change event for a <select> element, by using IHtmlSelectElement.Change.
When I do this I get an exception saying

The element does not have an event handler for the event 'onchange', nor any other events.

How come?

[egil]

Can you please share the code where you bind to the @onchange event? Otherwise it is hard to help you.

[Robelind]

I don't bind to the onchange event myself, it is done by a third party component (Telerik DropDownList).
Or so I thought. Could the problem be that the component doesn't bind to the event and handles
the selection in some other way?

[egil]

I cannot remember how the Telerik DropDownList works, but perhaps @EdCharbeneau can you help you with this?

Meanwhile, you can always inspect cut.Markup and look for blazor:onchange attributes or similar event handler bindings to find where there is an event you can trigger in the DOM.

[Robelind]

The markup is some <span>s and a hidden <select> and none of the elements has any event bindings.
Seems that the whole thing is handled entirely in Javascript.

[egil]

In that case, you cannot trigger the Telerik DropDownList through the event handlers triggers in bUnit, since there are none. What you can try is to trigger the JSInvocableMethod method in the Telerik DropDownList directly, that the JavaScript would have called normally, e.g.:

// telerikDropDownList is a reference to the component instance
var telerikDropDownList = cut.FindComponent<TelerikDropDownList>().Instance;

// Now you need to figure out what public method to call to emulate the change event
telerikDropDownList....