Sorting in Dojo 1.5 datagrid doesn't work - sorting

Question

I have built a dojo 1.5 datagrid + dojox.data.JsonRestStore. When the grid renders I can see the "carrot" that shows that sorting has fired and is on defaulting the right column. However, the content of the column(string values - field: 'projectShortName',...see code below) are not actually sorted. Hitting the descending/ascending button doesn't change the order or the rows. They are essentially locked in. I am not sure why?
I have column sorting turned off for certain columns and on for others using the canSort(). I only have formatters for calls with columns that have the sort turned OFF. I have tried making all columns sortable or only just the one that I really wanted. No dice.
Here is the layout/grid code:
var layout = [{
field: '_item',
name: '&nbsp',
formatter: selectFormatter,
width: '25px'
},
{
field: 'projectName',
name: 'Project Name',
width: '325px'
},
{
field: 'projectShortName',
name: 'Short Name',
width: '80px'
},
{
field: 'projectAreaName',
name: 'RQM Project Area',
width: '175px'
},
{
field: '_item',
name: 'Test Guide Status',
width: '190px',
formatter: testCaseGenerationOptionFormatter
},
{
field: 'projectOwner',
name: 'Owner',
width: '140px'
},
{
field: 'projectCreationTime',
name: 'Created Date',
width: '100px'
},
{
field: 'projectLastUpdateTime',
name: 'Last Modified Date',
width: '120px'
}];
dojo.empty(dojo.byId('workspaceGridContainer'));
if (dijit.byId("projectGrid")) {
dijit.byId("projectGrid").destroyRecursive();
}
// Create a new grid:
var grid = new dojox.grid.DataGrid({
id:'projectGrid',
onHide: dojo.hitch(this, function() {
dijit.byId("projectGrid").destroyRecursive();
}),
store: jsonStore,
clientSort: true,
autoHeight: true,
//sortInfo: "-2",
selectionMode: 'single',
rowsPerPage: '100',
structure: layout
},document.createElement('div'));
dojo.byId("workspaceGridContainer").appendChild(grid.domNode);
// Call startup, in order to render the grid:
grid.startup();
//var test = grid.setSortInfo(obj);
// Prevent sorting on column 1
grid.canSort = function(col){ if((Math.abs(col) == 1) || (Math.abs(col) == 5) || (Math.abs(col) == 6) || (Math.abs(col) == 7) || (Math.abs(col) == 8)) { return false; } else { return true; } };
var index = grid.getSortIndex();
if(index!=2) {
if(grid.canSort(2)){
grid.setSortIndex(2, false);
}
}
As you can see commented out I have tried sortInfo as well. Any advice would be appreciated!
-Doug

Answer 1

You may be using the wrong comparison operator. The dojo documentation uses the strict equal '===' whereas you only use the equal '=='. This causes problems in js, especially when you're comparing a literal, i.e. '1' with an object: 'Math.abs(col). The official grid.canSort method should be coded as follows:
function canSort(col){ return Math.abs(col) === 2;}
Note Mozilla's description of the equal operator, and the type conversion js uses to resolve different data types:
https://developer.mozilla.org/en/JavaScript/Reference/Operators/Comparison_Operators
Equal (==) - If the two operands are not of the same type, JavaScript converts the operands then applies strict comparison. If either operand is a number or a boolean, the operands are converted to numbers if possible; else if either operand is a string, the other operand is converted to a string if possible. If both operands are objects, then JavaScript compares internal references which are equal when operands refer to the same object in memory.