jqGrid loses selections when request is cancelled - jqgrid

Question

I have a requirement to allow a user to cancel a jqGrid (Version 4.4.1) paging or sorting operation if they have any selections that they do not want to lose.
I initially attempted to handle this in the beforeRequest event handler but when I call the selarrrow function an empty array is always returned as the selections appear to have already been cleared.
I then tried adding onPaging and onSorting event handlers where the selections were available via the selarrrow function, however, when I return 'stop' from these functions to cancel the request (as specified in the jqGrid documentation) the selections still appear to have been cleared. Note the rows still appear selected in the grid but selarrrow returns an empty array.
I'm guessing this is a jqGrid defect but does anyone know if it has been fixed in a more recent release or if there is a configuration workaround?

Answer 1

I think that there are just a bug in usage of onPaging. If the method return "stop" the selection still cleared. The reason is the order of the lines in the code fragment
clearVals = function(onpaging){
var ret;
if ($.isFunction(ts.p.onPaging) ) { ret = ts.p.onPaging.call(ts,onpaging); }
ts.p.selrow = null;
if(ts.p.multiselect) {ts.p.selarrrow =[]; setHeadCheckBox( false );}
ts.p.savedRow = [];
if(ret==='stop') {return false;}
return true;
};
The correct code should be
clearVals = function(onpaging){
var ret;
if ($.isFunction(ts.p.onPaging) ) { ret = ts.p.onPaging.call(ts,onpaging); }
if(ret==='stop') {return false;}
ts.p.selrow = null;
if(ts.p.multiselect) {ts.p.selarrrow =[]; setHeadCheckBox( false );}
ts.p.savedRow = [];
return true;
};
You can move the line 2045 (with if(ret==='stop') {return false;}) of jquery.jqGrid.src.js of the version 4.5.2 (which corresponds the line 1902 in version 4.4.1) after the 2041 (the line 1898 in version 4.4.1) (after if ($.isFunction(ts.p.onPaging) ) { ret = ts.p.onPaging.call(ts,onpaging); }) to fix the bug.
The usage of onSortCol seems be correct and if the callback returns "stop" string the selection should stay unchanged.
UPDATED: I posted the corresponding bud fix as pull request. It's merged today (see here) to the main code of jqGrid. So the next version (>4.5.2) should not have more the problem which you described.

Answer 2

This is the workaround I have put in place for this problem (note: it requires Underscore.js) but interested in a cleaner solution if anyone has one:
var tempSelections,
myGrid = $("#mygrid"),
checkSelections = function() {
var selections = myGrid.jqGrid("getGridParam", "selarrrow");
if (selections && selections.length > 0) {
tempSelections = selections;
}
};
myGrid.jqGrid({
... //settings
multiselect: true,
onPaging: checkSelections,
onSortCol: checkSelections,
beforeRequest: function() {
if (tempSelections && tempSelections.length > 0) {
if (!confirm("Do you want to clear the selections on this page?")) {
_.forEach(tempSelections, function(selection) {
myGrid.jqGrid("setSelection", selection);
});
tempSelections = null;
return false;
}
tempSelections = null;
}
return true;
}
});