How to manage stateSave value when we change the table?

lenamtl

Hi,

How to manage stateSave value when the table get changed?

I'm wondering what will be the best approach in the case we have stateSave values for a table
and the table get changed if we add, remove a column or change column order ....

Because when doing this datatables will throw an error if we don't clear the stateSave values...

Does the only available method is to clear the stateSave values?

As it is not easy to parse the stateSave value so I'm out of idea...

colin

Hi @lenamtl ,

The callback function, stateLoadCallback, is a good place to manipulate the saved data. You could probably detect if the table shape has changed and just destroy that saved information so that it starts fresh.

Cheers,

Colin

lenamtl

How do you detect the table shape have changed?

colin

By counting the columns and the rows. You could store the value that was relevant to the saved state in the saved data with stateSaveParams, and compare it again when it's reloaded.

lenamtl

It won't cover the case if a column was changed, let say the column was for address and get change to phone, so column equal the same qty as before...

is there a way to save custom settings in stateSaveParams?

Maybe having a way to version individual table could be another solution,

For now, I will continue to delete the stateSave value using my update script as there is no easy way to update the stateSave values (this is not easy to parse the stateSave values) and may produce errors and delay for nothing if there is no changes..

colin

Hi @lenamtl ,

stateSave isn't that smart - see this example here. It only stores the current searches, orders, and paging position (plus a time check). So if the column types changed, it wouldn't know about it, or care even.

Cheers,

Colin

lenamtl

Yes I know this is why this is hard to parse...

How would you compare both result ?

colin

Hi @lenamtl .

If you take a look at the console in that example I posted, you'll see it's just a structure. So you can do checks like data.columns.length for example.

Cheers,

Colin

lenamtl

I figured out

From Datatables

 console.log(
        'Number of all columns',
        $('#example').DataTable().columns().nodes().length
    );

from LocalStorage

var mycolumns = $('#example').DataTable().state().columns;
var count= Object.keys(mycolumns).length;
console.log(' localstorage ' + count);