[patch][cla] (Compat grid) QueryReadStore sends two requests when sorting on grid columns

[guest]

If you hook QueryReadStore? to a grid via DojoData? and click a grid column to sort it makes a double request, each with the same data.

See the attached files for a simple demo.

[jaredj]

I believe this is a grid problem, not a store problem. Ben, I know you made changes to grid to try and solve the double-fetch issue. Can you verify those changes didn't get regressed out?

[benschell]

This bug isn't specific to QueryReadStore?. In fact, any dojo data store used will have the fetch() function called twice for a sort. The problem lies in the Grid receiving a 'change' event when the row count is set as a result of a normal 'onBegin' call from the store.

My solution proposed in the patch is to add two new listeners to the Grid for a 'BeginUpdate?' and 'EndUpdate?' event from the model. The functionality for delaying updates until all updates are complete is already built into the Grid, so simply notifying the Grid that the model is in flux should be sufficient.

Part of this patch also adjusts the Grid for the note left in the comments, that the beginUpdate and endUpdate functions do not take into account the possibility of multiple beginUpdate calls (aka, nested updating calls). Now, endUpdate checks that it is the final endUpdate call and handles all updates (aka, if/if rather than if/else as previous).

Feel free to tear this one up, it's kindof a big patch for such a small problem, but it should help out for other issues in the future, as it ensures a way for the Model to notify the grid of an in-progress update.

[guest]

Unfortunately this patch leads to the grid not showing all rows as expected. In a grid with 115 entries, only about 60 of rows are fine, all the other rows just show three dots in each cell. Quick tests have shown, that always the same rows and subrequests are affected. Firebug does not display any errors. Firefox and IE make no difference here. I am using plain dojox.grid and dojox.data.QueryReadStore? (1.1.0). Your patch was applied with all chunks succeeding.

All rows show valid data after undoing the patch.

Will post a copy of the JSON data and dojo markup if you like.

[benschell]

Small typo. New patch uploaded.

[guest]

Thank you very much, 6567-2 works as expected. No more cells showing up as dots. Excellent. Cheers, Sascha.

[remi]

How is the current status with this Patch? Will we see it in 1.2?

[benschell]

I'm not sure if this bug persists or not, but the patch most certainly isn't still applicable given the rewrite in most of the Grid code. I'm not prepared to re-investigate before 1.2, so un-owning this bug.

[benschell]

After some discussion with Jared J., this bug apparently does not exist in the new version of the Grid. However, it (obviously) persists in the compat version. Adding a new patch (with no changes other than directory structure) which fixes this issue.

[jaredj]

Applied to compat, used BackwardsCompatibilityTest?, verified double-fetch no longer occurs.

Tested on:

IE 6

Firefox 2.0

Safari 3.1

[jaredj]

(In [14502]) Fixing double-fetch issue. \!strict fixes #6567