lib/Ext/util/Sortable.js
function(sorters, direction, where, doSort) {
        var me = this,
            sorter, sorterFn,
            newSorters;
        
        if (Ext.isArray(sorters)) {
            doSort = where;
            where = direction;
            newSorters = sorters;
        }
        else if (Ext.isObject(sorters)) {
            doSort = where;
            where = direction;
            newSorters = [sorters];
        }
        else if (Ext.isString(sorters)) {
            sorter = me.sorters.get(sorters);

            if (!sorter) {
                sorter = {
                    property : sorters,
                    direction: direction
                };
                newSorters = [sorter];
            }
            else if (direction === undefined) {
                sorter.toggle();
            }
            else {
                sorter.setDirection(direction);
            }
        }
        
        if (newSorters && newSorters.length) {
            newSorters = me.decodeSorters(newSorters);
            if (Ext.isString(where)) {
                if (where === 'prepend') {
                    sorters = me.sorters.clone().items;
                    
                    me.sorters.clear();
                    me.sorters.addAll(newSorters);
                    me.sorters.addAll(sorters);
                }
                else {
                    me.sorters.addAll(newSorters);
                }
            }
            else {
                me.sorters.clear();
                me.sorters.addAll(newSorters);
            }
            
            if (doSort !== false) {
                me.onBeforeSort(newSorters);
            }
        }
        
        if (doSort !== false) {
            sorters = me.sorters.items;
            if (sorters.length) {
                //construct an amalgamated sorter function which combines all of the Sorters passed
                sorterFn = function(r1, r2) {
                    var result = sorters[0].sort(r1, r2),
                        length = sorters.length,
                        i;

                        //if we have more than one sorter, OR any additional sorter functions together
                        for (i = 1; i < length; i++) {
                            result = result || sorters[i].sort.call(this, r1, r2);
                        }

                    return result;
                };

                me.doSort(sorterFn);                
            }
        }
        
        return sorters;
    }
function(sorters, direction, where, doSort) {
        var me = this,
            sorter, sorterFn,
            newSorters;
        
        if (Ext.isArray(sorters)) {
            doSort = where;
            where = direction;
            newSorters = sorters;
        }
        else if (Ext.isObject(sorters)) {
            doSort = where;
            where = direction;
            newSorters = [sorters];
        }
        else if (Ext.isString(sorters)) {
            sorter = me.sorters.get(sorters);

            if (!sorter) {
                sorter = {
                    property : sorters,
                    direction: direction
                };
                newSorters = [sorter];
            }
            else if (direction === undefined) {
                sorter.toggle();
            }
            else {
                sorter.setDirection(direction);
            }
        }
        
        if (newSorters && newSorters.length) {
            newSorters = me.decodeSorters(newSorters);
            if (Ext.isString(where)) {
                if (where === 'prepend') {
                    sorters = me.sorters.clone().items;
                    
                    me.sorters.clear();
                    me.sorters.addAll(newSorters);
                    me.sorters.addAll(sorters);
                }
                else {
                    me.sorters.addAll(newSorters);
                }
            }
            else {
                me.sorters.clear();
                me.sorters.addAll(newSorters);
            }
            
            if (doSort !== false) {
                me.onBeforeSort(newSorters);
            }
        }
        
        if (doSort !== false) {
            sorters = me.sorters.items;
            if (sorters.length) {
                //construct an amalgamated sorter function which combines all of the Sorters passed
                sorterFn = function(r1, r2) {
                    var result = sorters[0].sort(r1, r2),
                        length = sorters.length,
                        i;

                        //if we have more than one sorter, OR any additional sorter functions together
                        for (i = 1; i < length; i++) {
                            result = result || sorters[i].sort.call(this, r1, r2);
                        }

                    return result;
                };

                me.doSort(sorterFn);                
            }
        }
        
        return sorters;
    }
Sorts the data in the Store by one or more of its properties. Example usage:

//sort by a single field
myStore.sort('myField', 'DESC');

//sorting by multiple fields
myStore.sort([
{
property : 'age',
direction: 'ASC'
},
{
property : 'name',
direction: 'DESC'
}
]);

Internally, Store converts the passed arguments into an array of {@link Ext.util.Sorter} instances, and delegates
the actual sorting to its internal {@link Ext.util.MixedCollection}.

When passing a single string argument to sort, Store maintains a ASC/DESC toggler per field, so this code:

store.sort('myField');
store.sort('myField');

Is equivalent to this code, because Store handles the toggling automatically:

store.sort('myField', 'ASC');
store.sort('myField', 'DESC');

@param {String/Ext.util.Sorter[]} sorters Either a string name of one of the fields in this Store's configured
{@link Ext.data.Model Model}, or an array of sorter configurations.
@param {String} [direction="ASC"] The overall direction to sort the data by.
@param {String} [where]
@param {Boolean} [doSort]
@return {Ext.util.Sorter[]}