feat(dropdown): add option to let event propagate on toggle

[H--o-l]

Issue #1217 was fixed but re-introduce
recently in development branch (commit 04cab1e).

Let's add an option to authorize propagation of click event on toggle
for users that need it.

[valorkin]

@H--o-l question is: if add (click)="return false;" should it do the same?

[valorkin]

@H--o-l as far as I remember I was fighting with document click closing just opened dropdown :)

[H--o-l]

@valorkin ok, not sure what you mean but I'm glad to do some tests if you have ideas.

For now I tried:
<button dropdownToggle (click)="false"> which doesn't work and <button dropdownToggle (click)="return false"> which doesn't compile.

Before submitting the PR I also tried to remove the event.stopPropagation() in dropdown-toggle directive and it was ok for my app.

Do you have other suggestions ? Or did I missed something ?

[valorkin]

what if completely remove event.stopPropagation() from drop down toggle
but (click)="$event.stopPropagation()" should work in the same way
need to try this
cc #2800

[H--o-l]

@valorkin just to add water under the bridge, you did say, in this discussion #1217, that twitter bootstrap stop the click event.
I don't know twitter bootstrap myself but it's seems a legitimate reason to put event.stopPropagation() where you did, but we need the option to desactivate it :-)

[valorkin]

https://github.com/twbs/bootstrap/blob/v4-dev/js/src/dropdown.js#L205-L209

[valorkin]

yep they use it a lot

[codecov]

Codecov Report

Merging #2964 into development will decrease coverage by <.01%.
The diff coverage is 66.66%.

@@               Coverage Diff               @@
##           development    #2964      +/-   ##
===============================================
- Coverage        65.78%   65.77%   -0.01%     
===============================================
  Files              207      207              
  Lines             5608     5610       +2     
  Branches           984      985       +1     
===============================================
+ Hits              3689     3690       +1     
  Misses            1656     1656              
- Partials           263      264       +1

Impacted Files	Coverage Δ
src/dropdown/bs-dropdown-toggle.directive.ts	82.75% <66.66%> (-2.43%)	⬇️

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[valorkin]

@H--o-l thanks again :)
we will see where it will take us

[H--o-l]

@valorkin thanks to you !

[valorkin]

My hope to release it today