[TextField] Spurious onBlur() with undefined event

[nareshbhatia]

onBlur() is being called on a TextField with event parameter as undefined

• I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior

onBlur() should always be called with an event.

Current Behavior

In some situations, onBlur() is being called with an undefined event.

Steps to Reproduce (for bugs)

I am not able to reproduce this in a small example, but I can tell you which code path is making this spurious call to onBlur. The culprit is essentially the componentWillUpdate() method in Input.js. See here.

1. On line 395, there is a call to muiFormControl.onBlur(), without passing an event!!!
2. This calls FormControl.handleBlur(), which expects an event.
3. This in turn calls this.props.onBlur(event), which is my event handler that gets an undefined event.

Context

This issue is requiring me to check for an undefined event in the beginning of my event handler.

Your Environment

Tech	Version
Material-UI	1.0.0-beta.20
React	16.0.0
browser	Chrome
etc

[oliviertassinari]

@nareshbhatia This is a nice finding. The logic was introduced in order to fix #8811. What do you think of asserting that the event is defined before triggering the property callback here?
https://github.com/callemall/material-ui/blob/86dbd4986c6fdc1f32c088abb3b73d25974272e8/src/Form/FormControl.js#L180-L182

[nareshbhatia]

@oliviertassinari, I think that would work perfectly. It is essentially what I am doing in my event handler, but better to catch this upstream in the framework code.

[oliviertassinari]

@nareshbhatia Do you want to give it a try?

[nareshbhatia]

Sure. Will send you a PR.

[reznord]

@oliviertassinari in current stable version (v0.19.x) it is not possible to use onBlur() for textFields right?

If so, where do you recommend to validate the fields? (onChange)?

[oliviertassinari]

@reznord I have no clue.