OlegK on small improvements in $.ajax which load grid contain

Thu, 22 Sep 2011 12:57:14 +0300

Hello Tony,

I have some small suggestion to improve in the code of grid.base.js in the call of $.ajax (see the lines 1687-1710).

1) Add the second parameter to the beforeSend callback and forward it to loadBeforeSend:

beforeSend: function (xhr, settings) {
beginReq();
if ($.isFunction(ts.p.loadBeforeSend)) { ts.p.loadBeforeSend.call(ts, xhr, settings); }
}

It will simplify implementation of loadBeforeSend for example in case of setting custom authentication headers.

2) Include additional event beforeResponseProcessing which will be called directly at the begining of success callback:

success: function (data, st, xhr) {
if ($.isFunction(ts.p.beforeResponseProcessing)) {
ts.p.beforeResponseProcessing.call(ts, data, st, xhr);
}
if (dt === "xml") { addXmlData(data, ts.grid.bDiv, rcnt, npage > 1, adjust); }
...

The new event (callback) can gives more flexibility in the usage of jqGrid.

Just two examples where it can be usefull:

a) I have grids where many columns with chechboxes exist. Depend on data contain it can be very usefull to hide some columns where in full grid contain the chechboxes in the columns have false (uncheched). If allow to show only important information. I used userdata to send to jqGrid information which columns should be hidden. If one hide the columns before filling of the grid (in the new beforeResponseProcessing) the web browser can caclulate grid width abd the whole page layout more effectively. If I hide the columns one after the another inside of loadComplete the web browser have more work and grid work slowly.

b) Sometine one uses datatype as the function only to have simple way to make modification in the grid response (some decoding of data or creating an additional column based of other columns) before forwarding the data from the server to jqGrid. The introduction of new beforeResponseProcessing callback parameter will make the usage of datatype as the function unneeded in the case.

3) Include the code of success and error callbacks before

endReq();

in the try {...} catch(ex) {} block. It will make hiding of loading div work allways even if some errors occuer. One can additionally include an alert or some other error message (till to calling user callback like loadError) in the catch block. Alternatively one can move endReq(); from both success and error callbacks in the additional complete callback. The small disadvantage of the way will be unblocking of grid (or hiding of loading div) at the beginning of filling of jqGrid and calling of loadComplete handler. This can change the behavier of the user GUI of jqGrid.

Best regards
Oleg

jQuery Grid Plugin - jqGrid - Topic: small improvements in $.ajax which load grid contain

OlegK on small improvements in $.ajax which load grid contain