Adding clear btn callback

[anonymous-ME]

What issue does this pull request resolve?
onInputChange not called when input cleared. Fix for this issue #594

What changes did you make?
added the callBack

Is there anything that requires more attention while reviewing?
nope

[codecov]

Codecov Report

Merging #630 (c1e21a3) into master (c50cbca) will increase coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head c1e21a3 differs from pull request most recent head 5e18602. Consider uploading reports for the commit 5e18602 to get more accurate results

@@           Coverage Diff           @@
##           master     #630   +/-   ##
=======================================
  Coverage   99.84%   99.84%           
=======================================
  Files          44       44           
  Lines         661      663    +2     
  Branches      134      135    +1     
=======================================
+ Hits          660      662    +2     
  Misses          1        1           

Impacted Files	Coverage Δ
src/core/Typeahead.js	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c50cbca...5e18602. Read the comment docs.

[coveralls]

Coverage increased (+0.0005%) to 99.849% when pulling 5e18602 on anonymous-ME:master into c50cbca on ericgio:master.

[coveralls]

Coverage increased (+0.0005%) to 99.849% when pulling 5e18602 on anonymous-ME:master into c50cbca on ericgio:master.

[ericgio]

Hey @anonymous-ME, thanks for submitting this PR. The issue you're trying to solve with this change is actually a bit more complicated than it first appears. onInputChange also passes the change event as the second argument, but that event doesn't actually happen, since the value changes in response to a click on a different element.

[ericgio]

As noted, onInputChange passes the change event as the second argument. It also doesn't seem like a good idea to trigger a callback during a state change. That should happen after the state change is complete.

[ericgio]

Oh, and if you'd like to continue pursuing this change, some tests would be great :)

[anonymous-ME]

Hey @anonymous-ME, thanks for submitting this PR. The issue you're trying to solve with this change is actually a bit more complicated than it first appears. onInputChange also passes the change event as the second argument, but that event doesn't actually happen, since the value changes in response to a click on a different element.

Hi @ericgio, what solution would you suggest in this case?

[anonymous-ME]

Should we add a callback for onClear instead?

[ericgio]

I think the solution is that the event needs to be manually triggered by the clear callback, which would then trigger onInputChange as one would expect.

[anonymous-ME]

Hi @ericgio, I'm thinking of doing something like this to simulate onChange for TypeaheadManager.

  const event = new Event('change');
  element.dispatchEvent(event);

But not sure how to get TypeaheadManager element reference inside of clearTypeahead callback.

[ericgio]

Thanks for having a look at this! The callback was added in v5.2