When serverSide is on not all selected items are being selected

[demetris-manikas]

Hi.
I believe I stumbled on a bug.
The preXhr listener preXhr.dt
attempts to give a solution to keeping the selected items in place when serverSide is on.
The code misses to account for more than two consecutive xhr requests since the whole list of
selected items is not kept but rather only the list of selected in the current page.
Thanks

[AllanJard]

Can you give me a link to a page showing the issue please?

[demetris-manikas]

Hi again.
I prepared the following codepen to showcase the problem.

To see what I mean follow this steps.
Select the first couple of rows and then scroll down until an alert will stop you then scroll up again the selection is lost.
Now select rows 7, 8 and 9. Scroll down again and after the first alert if you scroll back the selection is still there only for 8 and 9 but NOT for 7
I understand why this is. I realized that there is a bug by just reading the code.
The plugin needs to keep track of all the selections made at all time and not only the ones the
current page has.

[AllanJard]

I see what you mean - thanks for the clarification. Yes, I agree - this is a feature that is not yet implemented in Select.

Part of the reason for that was that I'm not yet sure how to handle something like "Select all" when server-side processing. It would be easy to have an "all" flag, but then say to remove one or two from the selection, it starts to get a bit complicated.

It is something we need to handle, it just isn't implemented yet I'm afraid.

[demetris-manikas]

I have to make the decision now and what I ended up with is the following.
Let the selectAll function as is and supply the user with the select all (really all) option if necessary
just before an action must be performed.
Replacing the current selectAll option to select all rows in the "db" is not an option
since the user wont be able to select all the items in a page as he might want to.
To sum up I propose that the plugin holds on to a list of all the selected ids that should be available to the programmer
and leave the complicated situation to the plugin's user to solve.

[demetris-manikas]

Hi. I have some thoughts to share on the matter.
The way I would go about to handle the selectAll option would be to
keep a list of selected or deselected items along with a mode;
When the selectAll options is selected the mode is turned to 'exclude'
the list of user selections/deselection is cleared and whenever a row is DEselected it gets stored in the list.
When the selectAll options is DEselected the mode is turned to 'include'
the list of user selections/deselection is cleared and whenever a row is selected it gets stored in the list.
The plugin can then report the current selection as
{type: 'include'|'exclude', rows: rows} so that a query can be built on the info provided.

Actually I will implement this scheme for my current project anyways so if you are interested I could provide a PR on that

[AllanJard]

I would indeed be interested to see what you cook up :-)