adds updateViewDate option

[jelhan]

Implementation details are present in updated docs and added test. Default value does not change any existing behaviour.

I think this option will be helpful if you interact with bootstrap-datepicker via code. It allows you a more granular control how bootstrap-datepicker reacts on changes. It will be really powerful together with setViewDate method suggested in #1978.

Please have a review on syntax used in docs. I'm not quite sure if lists are supported and wasn't able to build docs to verify.

[acrobat]

@jelhan can you provide a jsfiddle example of a possible usecase so I can test the pr? Thanks!

[jelhan]

@acrobat Here you go: https://jsfiddle.net/pkpx6baw/ Also note that tests are included in PR.

[acrobat]

Thanks @jelhan

[vsn4ik]

Hmm... Maybe (!which || which === 'view') && this.o.updateViewDate?

[jelhan]

@vsn4ik (!which || which === 'view') && this.o.updateViewDate would make it impossible to change viewDate if updateViewDate is false. Perhaps _setDate should be better documented.

[Azaret]

This feature actually breaks the default and expected behavior of the picker.
It should be set to false by default.

Moreover can we have some use cases on why anyone would want to set this to true ?
I'm not convinced.

[jelhan]

@Azaret Could you please provide a case where it breaks something? It should not change any existing behaviour if updateViewDate is set to true which is default.

[Azaret]

Change the month, call update and the picker goes back to the current month.
This issue is that when set to true viewDate is not updated anymore so any call made to update, setDates, ... will reset the view. I'm not sure in which case we would want sure behavior.

Now maybe there is a side effect with another change, but I noticed that turning that false solve the issue of the view being reset.

[jelhan]

@Azaret I'm not quite sure what you mean. I see same behavior in 1.6.4: https://jsfiddle.net/1gv2vwau/