Dropdown onChange callback should only be called when the selected value changes

[spencer-brown]

Bug Report

Steps

• Create a Dropdown with value and onChange props.
• Click the Dropdown and then click outside of the value-displaying-box and dropdown list.

Expected Result

The onChange callback should not be fired because I haven't selected a new value. This is how HTML's select behaves.

Actual Result

The onChange callback is called even though the selected value has not changed.

Version

0.82.3

Testcase

https://codesandbox.io/s/5z379wy7ol

[husseyexplores]

You can pass selectOnBlur={false} as a prop to prevent this behavior.
I'm not sure if this intentional (i.e passing selectOnBlur explicitly). I can work on this if this needs to behave as expected.
Edit: I personally think selectOnBlur should be false by default because that is the normal HTML Select element behavior.

[spencer-brown]

ah, thanks @husseyexplores !

I agree with you - I think that it makes more sense for selectOnBlur to default to false for the sake of achieving parity w/ HTML.

[spencer-brown]

This is still an issue beyond the blur case btw - if you click the already-selected item in the dropdown list, the onChange callback is called. This too is different than HTML's behavior.

[levithomason]

Superb report, thanks much. The current dropdown calls onChange on blur even if the value doesn't change, which is certainly not correct. Here's an updated example comparing a native DOM select to the Dropdown: https://codesandbox.io/s/43r9899x4

We need to update the Dropdown to behave just as the regular HTML select in this regard.

[zarend]

#3391

[spencer-brown]

@levithomason , how does @zarend 's PR look?

[layershifter]

Was fixed in #3391 🎉

[spencer-brown]

thanks @zarend @levithomason & @layershifter !