Maintain sort property order when changing sort direction

[cmrgKoradir]

SETUP
Take any GridPro and make it multi-sort.

Experienced under:
Vaadin 14.2.3
Chrome 84.0.4147.89 (Official Build) (64-bit)
Ubuntu 20.04.1 LTS

IS
Whatever sort property you activate last is considered the one that should be sorted by first.
(Weird behaviour, imo, but apparently a feature since vaadin/vaadin-grid#1624 was not labelled a bug.)
If you have multiple sort properties selected, and you change the sort direction of one, that will count as being "activated last" and will therefore become the new first sort property.

SHOULD
Changing sort direction on an already active sort property should maintain the existing sort order.

[tomivirkki]

This also is intended behavior and not a bug. I took a look at some of the other data grids out there and seems that some follow the same behavior (the last sorted column gets the first priority in sorting) and some do the opposite. Changing this now in vaadin-grid would be a breaking change, UX-wise. What we could do is to offer some more control over what happens on column sort so it would be easier to apply individual preferences for the behavior. But that would also be an enhancement, not a bugfix.

Some adjustments can be made with the current API already:

• Use dataProvider instead of items. It will receive the sort order on every data request. Using this information, the application logic can handle the effective sort order in any fashion.
• If the sorter arrow numbering doesn't follow the desired behavior, the numbers can be hidden with a style module or vaadin-grid can be extended (or monkey-patched) to override the numbering logic in vaadin-grid-sort-mixin (the latter option would of course mean accessing private API)

[cmrgKoradir]

I will admit, I am VERY surprised this is "intended behaviour" because it's confusing to just about everybody I show this to.

I took a look at some of the other data grids out there and seems that some follow the same behavior

Of course they do, they quite simply have no other choice if they want to use "plain Vaadin".

Use dataProvider instead of items. It will receive the sort order on every data request. Using this information, the application logic can handle the effective sort order in any fashion.

Yes, but maintaining the sort property order when you change the sort direction requires either overriding the sort property selection logic in the vaadin component or slapping additional bookkeeping on top of it to correct vaadin's selection before we pass it on. Because we can no longer make assumptions about the property order in the backend.

[tomivirkki]

Of course they do, they quite simply have no other choice if they want to use "plain Vaadin".

I meant data grids from vendors other than Vaadin

Yes, but maintaining the sort property order when you change the sort direction requires either overriding the sort property selection logic in the vaadin component or slapping additional bookkeeping on top of it to correct vaadin's selection before we pass it on. Because we can no longer make assumptions about the property order in the backend.

Yes, additional bookkeeping would most likely be required. A dedicated API for the purpose would be ideal.

[mvysny]

@tomivirkki could you please post links to videos or pages from those vendors other than Vaadin, so that we can compare?

[tomivirkki]

@mvysny Here's one https://fancygrid.com/samples/sorting/multi

[web-padawan]

To me it looks like the proper way of fixing this would be adding new property e.g. reverseSortOrder to modify this block:

web-components/packages/grid/src/vaadin-grid-sort-mixin.js

Lines 83 to 85 in b4dec66

	if (sorter.direction) {
	this._sorters.unshift(sorter);
	}

  if (this.reverseSortOrder) {
    this._sorters.push(sorter);
  } else {
    this._sorters.unshift(sorter);
  }

Then we would also need to update sorters when reverseSortOrder is set to true / false while grid is already sorted.