Dijit Time picker bug

[m.baldoncini]

We found a bug on the time picker.

Before version 1.9 it's possible to set the visibleRange property, that loads and shows only the times comprised in the range; furthermore, there are two arrows above and below to scroll the hidden times.

Starting from version 1.9 it isn't possible to set the visibleRange property anymore: because of this, the select component is always filled with each time of the day: this causes slow loading when the times are configured with a small interval between each other.

[bill]

As explained in #18220, the time picker has been intentionally rearchitected, replacing the up/down arrows with normal scrolling, so thus the visibleRange property was intentionally removed.

Is your main issue performance? I do see an inefficiency in the current code. It would theoretically be faster if _getFilteredNodes() returned a DocumentFragment and _showText() just appended it to this.domNode all at once, rather than looping through each node.

[bill]

I made the performance optimization at 50278e40c6b4c549f7ca1041e17890df521617af.

[m.baldoncini]

Thank you for the code! Anyway, I've tried it and the performance issue is still there, there isn't any noticeable improvement from the previous version: I click on the time picker (5 minutes range) and it takes quite a bit to load the list, I click outside the time picker and it takes quite some time to hide itself; the same holds true when I select a value from the TimePicker?.

Perhaps the problem is due to the fact that every time is loaded at once? Did you notice the performance issue yourself? I'm testing it with Google Chrome 43, both on Windows and Linux.

[bill]

OK, I see the slowness creating the picker, although no problem hiding it. I traced the JS and it seems like that dojo/date/locale.format() is slow, specifically from format() --> _getGregorianBundle() --> mixin().

Although lazy-loading the drop-down list is one option, that's too complicated. I have a simpler solution which I filed as #18629 and ​https://github.com/dojo/dojo/pull/159. It gives about a 5x speed improvement.

[m.baldoncini]

Great, I confirm that the GregorianBundle? caching is quite effective: the time picker drop down rendering speed is now acceptable. Thank you very much for your effort!

[bill]

Good. Note that #18629 has now been pushed and backported.