Fix applications service error

[jrahmatzadeh]

The service will be undefined when user don't use application blur.

Since ?. is supported in 40 and higher, we can use that to avoid calling undefined properties.

Related to #312

[TanawatJukmongkol]

Yup. Looks like that's the fix. I think in the long run, using monads to check for undefined or null, instead of if statements could be beneficial (that's just my thoughts on this).

[TanawatJukmongkol]

Now that I think about it... If this.service is undefined, then this could mean there's some undefined behavior else where (which, if that's the case would make this only a work around). And not calling the service.unexport might lead to memory leak (because this.DBusImpl will not be unexported)?

[jrahmatzadeh]

@TanawatJukmongkol
No, that's happening because the enable method hasn't been called before (as I explained in the commit).
And ?. is just a quick fix because I didn't want to change the architecture.
Basically, when it's not enabled, the first line of disable function should return.

This error is not easy to find on review time, that's why I didn't catch it on ego review.

[TanawatJukmongkol]

@justperfection Ahh, I see. Thank you for the clarification. 😊

I have to confess. I don't know much about gnome extension development, let alone the inner working of this extension, so I had to make lots of assumptions based on the source code, since there's no documentation. The code is super clean, and easy to understand though.

[aunetx]

Thank you very much, I'm kinda dumb and forgot that I choose to disable every component, even when they haven't been enabled before... That's stupid and I will change this behaviour, but at least this will fix the crash very well :)