Selection doesn't follow row when sorting in DataGrid

[Bryan Forbes]

When sorting a column after selecting a row, the selection should follow the item selected rather than the row index in the grid.

[Nathan Toone]

Reassigning to me

[Bertrand Fan]

This bug also applies when selectionMode="multiple":

If you look at the grid Multiple in this test: ​http://archive.dojotoolkit.org/nightly/dojotoolkit/dojox/grid/tests/test_selection.html

then toggle a few rows and sort by column, the selected rows are now different rows (at the same positions that they were before).

[David Schwartz]

Just to be clear, this issue exists whether the selectionMode is 'multiple', 'extended' or 'single'.

[xbillbill]

is it a difficult bug to fix?

[Nathan Toone]

It's moderately difficult to fix - what would need to happen is we'd need to keep track of selection on a per-item basis...rather than a per-row basis (as we currently are).

Most of the issue is making sure that we don't break other stuff in making that change. Patches are welcome - but I just don't have cycles to dedicate to solving this in the week before 1.4 gets frozen.

[jake richardson]

The above patch might break the compat grid, due to the getFirstSelected/getNextSelected not doing anything useful anymore.

[jake richardson]

Fails when selecting items not in the local cache...

[jake richardson]

Prevent selection from occuring when no item is available.

[jake richardson]

Above patch is still not usable due selection not working on rows that have not loaded their associated items from the store.

[jake richardson]

Identifier based selection management will not allow for virtualized selection (select all, or selecting an item and scrolling down and shift-selecting).

Alternative solution would be to deselect all selections when the filter or sort changes.

[Nathan Toone]

Yes - this is exactly the reason why I mentioned that it's moderately difficult to fix. Getting into the "guts" of the grid can be quite a pain at times...

[jake richardson]

I don't think this is an issue of difficulty, but rather an issue of capability. As far as I see it, there is no way to do identity based virtualized row selection management without the server participating in someway (full server side selection management, or row based identity querying interface), or by obtaining all item identifiers beforehand.

If anyone has a solution in mind that shows otherwise, please sketch it out.

[David Schwartz]

My $.02: This is a serious usability bug. The user doesn't select 'row 5' but rather 'object XXXXX'. Selection should definitely persist across sort events. This will really tick users off when they discover that their selection is lost.

[Nathan Toone]

Agreed - this bug *needs* to be addressed...the issue is that it's not a simple enough bug to address in the 1.4 timeframe. Especially given that the issue has existed since the dawn of Grid-time. :)

[jake richardson]

The above patch does work except for virtual selections (the following scenarios):

• select all (with the _CheckBoxSelector)
• select item, scroll over unloaded pages (so it won't load them), shift select

So it should work for most cases, just not when selecting items that have not been loaded.

[David Schwartz]

So will this remain open until working in all cases?

[Nathan Toone]

It will at least remain open until it's working in *some* cases... ;)

That is, I haven't applied the patch yet - I'll have to look at it and see what it would take to handle virtual selections. I'm guessing that virtual selections will not be able to be handled...because we don't *know* what items were selected (because they weren't loaded...we don't have their identity).

[Nathan Toone]

Unassigning my tickets.

[evan]

(In [25579]) Fixes #7304 !strict by leveraging selection persistence across DataGrid?, TreeGrid/LazyTreeGrid?. Refs #10855

The selection persistence feature is still limited with

1. Key precondition - Store Identifier(id) is required since id is used for differentiating row items.

2. Known issue - might not be accurate if some unloaded rows are selected by range(e.g.SHIFT + click)

Usage - To turn on this, please set 'keepSelection' attribute to true, e.g. <div dojoType="dojox.grid.DataGrid?" keepSelection = true .../> or

<div dojoType="dojox.grid.TreeGrid?" keepSelection = true .../> or <div dojoType="dojox.grid.LazyTreeGrid?" keepSelection = true .../>

[evan]

(In [25580]) Refs #10855 !strict use this.inherited() after the fix of #7304, refs #7304

[evan]

(In [25668]) Refs #7304 leveraging selection preserver with LazyTreeGrid?, also see [25579]

[evan]

(In [25740]) Refs #7304 !strict need to reset selectedById[] for deselectAll()

[Evan]

In [27122]:

Refs #7304, fix a regression caused by [25579] - selection shouldn't be cleared in _clearData() otherwise selections will be lost after being sorted, refreshed etc. Also applied to 1.7.* branch