Programmatically change grid column order - extjs

Question

I want to sort the columns in my grid, just like the rows. I have made a simple sort function that is called from an actioncolumn handler:
sortColumns:function(record) { // The record after which's values the columns are ordered
var columns = this.columns;
Ext.Array.sort(columns,function(col1,col2) {
if(record.get(col1.dataIndex) > record.get(col2.dataIndex)) return 1;
if(record.get(col1.dataIndex) < record.get(col2.dataIndex)) return -1;
if(col1.dataIndex > col2.dataIndex) return 1;
if(col1.dataIndex < col2.dataIndex) return 1;
throw new Error("Comparing column with itself shouldn't happen.");
});
this.setColumns(columns);
});
The setColumns line now throws the error
Cannot add destroyed item 'gridcolumn-1595' to Container 'headercontainer-1598'
which is because the "old" columns are destroyed first, and then the "new" columns, which are the same and thus destroyed, are applied.
I only want to change the order, but I didn't find any function to do it. Do you know how to do it?
Drag-drop ordering of the columns works, so it is doable; but I don't find the source code where sencha did implement that drag-drop thingy. Do you know where to look for that code?

Answer 1

Reconfigure method needs two arguments
grid.reconfigure(store, columns)
Here is the fiddle that changes the columns programatically https://fiddle.sencha.com/#fiddle/17bk

Answer 2

I have found that columns are items of the grid's headerCt, so the following works well, and unlike the other answers, it does not create new column components, keeping the column state and everything:
var headerCt = normalGrid.headerCt,
columns = headerCt.items.getRange();
Ext.Array.sort(columns,function(col1,col2) {
if(record.get(col1.dataIndex) < record.get(col2.dataIndex)) return -1;
if(record.get(col1.dataIndex) > record.get(col2.dataIndex)) return 1;
if(col1.dataIndex < col2.dataIndex) return -1;
if(col1.dataIndex > col2.dataIndex) return 1;
return 0;
});
headerCt.suspendLayouts();
for(var i=0;i<columns.length;i++)
{
headerCt.moveAfter(columns[i],(columns[i-1] || null));
}
headerCt.resumeLayouts(true);

Answer 3

There is a reconfigure method which can be used to achieve reordering, e.g:
grid.reconfigure(columns);
Check the this.

Answer 4

I couldn't manage to do it without storing columns in a custom field and using reconfigure, maybe someone can suggest something better (reconfigure doesn't work well with just regular columns field it seems):
Ext.define('MyGrid', {
extend: 'Ext.grid.Panel',
//just renamed "columns"
myColumnConfigs: [
//all your column configs
]
});
//to rearrange inside controller, also need to call it on grid render
var grid = this.getView();
var columns = grid.myColumnConfigs;
//...do your sorting on columns array
grid.reconfigure(columns);