Syncronize AJAX requests: Client or Server Sync?

[John Dendrinos]

Hello,

I have the following scenario:

I have a data grid which gets data for its rows from json (ajax). I have filters for some of the grid's columns. Also, I have an autupdate operation (polling), which is an AJAX request that retrieves only the updated rows, based on the filters and a session variable that keeps the latest update time and checks if the latest update time in the db is greater than the stored value. If it is the grid is updated (rows are added or updated).

My issue:

The filter operation collides with the polling operation. When a filter is entered by the user, depending on the timing, the polling operation gets called with this filter as a parameter (so it gets the udpated records filtered by the new filter) and returns before the filter operation has returned. In this case the grid is not update correctly as you can assume.

Is there any best practice on how to deal with this situation? When the polling is very frequent (every 1 sec) this issue arises every time.

I have never stumbled upon this issue and I am wondering if I should sync the two processes. And if so, should I sync in the server, or the client? And how?

Thank you very much in advance.

[Bear Bibeault]

Disable the polling while an update is in progress.