ZoomButtons: multiple calls to onLoadBefore and onLoadAfter per click

[yaro90]

I'm submitting a...

• [x] bug
• [ ] feature
• [ ] chore

What is the current behavior

Multiple calls to to onLoadBefore or onLoadAfter per click

What is the expected behavior

Single call to onLoadBefore or onLoadAfter per click

Please tell us about your environment

• Version: 1.3.2
• Browser: [all]

Other information

Possible solution is to add ignoreOnload flag which would be true until last interval is hit, but I'm not sure if optimal:

[amaneer94]

I used this solution from lodash debounce function, it helped me somehow.