remember after refresh selected row in extjs grid - extjs

Question

I have a problem. I use extjs grid. This grid will be refreshed every seconds.
I refresh with this function:
ND.refresh = function() {
ND.commList.load();
}
var refreshSeconds = refreshRate * 1000;
var t = setInterval('ND.refresh()', refreshSeconds);
But when someone selected a row to highlight it it reset this selection.
How can I remember the selected row and highlight it again after refresh?
This is my grid:
var grid = Ext.create('Ext.grid.Panel', {
autoscroll: true,
region: 'center',
store: ND.dashBoardDataStore,
stateful: true,
forceFit: true,
loadMask: false,
stateId: 'stateGrid',
viewConfig: {
stripeRows: true
},
columns: [{
text: 'Vehicle',
sortable: true,
flexible: 1,
width: 60,
dataIndex: 'vehicle'
}, {
text: 'CCU',
sortable: true,
flexible: 0,
width: 50,
renderer: status,
dataIndex: 'ccuStatus'
}]
});
Thanks guys

Answer 1

I wrote simple Ext.grid.Panel extension that automatically selects back rows that were selected before store reload. You can try it in this jsFiddle
Ext.define('PersistantSelectionGridPanel', {
extend: 'Ext.grid.Panel',
selectedRecords: [],
initComponent: function() {
this.callParent(arguments);
this.getStore().on('beforeload', this.rememberSelection, this);
this.getView().on('refresh', this.refreshSelection, this);
},
rememberSelection: function(selModel, selectedRecords) {
if (!this.rendered || Ext.isEmpty(this.el)) {
return;
}
this.selectedRecords = this.getSelectionModel().getSelection();
this.getView().saveScrollState();
},
refreshSelection: function() {
if (0 >= this.selectedRecords.length) {
return;
}
var newRecordsToSelect = [];
for (var i = 0; i < this.selectedRecords.length; i++) {
record = this.getStore().getById(this.selectedRecords[i].getId());
if (!Ext.isEmpty(record)) {
newRecordsToSelect.push(record);
}
}
this.getSelectionModel().select(newRecordsToSelect);
Ext.defer(this.setScrollTop, 30, this, [this.getView().scrollState.top]);
}
});

Answer 2

The straightforward solution is just save somewhere in js index of selected row. Then after reload you could easily select this row by index using grid's selection model.
Get selection model: http://docs.sencha.com/ext-js/4-0/#!/api/Ext.grid.Panel-method-getSelectionModel
var selectionModel = grid.getSelectionModel()
Get selected rows: http://docs.sencha.com/ext-js/4-0/#!/api/Ext.selection.Model-method-getSelection
var selection = selectionModel.getSelection()
Set selected row back: http://docs.sencha.com/ext-js/4-0/#!/api/Ext.selection.Model-method-select
selectionModel.select(selection)

Answer 3

Here is another way to select the previously selected record:
var selectionModel = grid.getSelectionModel()
// get the selected record
var selectedRecord = selectionModel.getSelection()[0]
// get the index of the selected record
var selectedIdx = grid.store.indexOfId(selectedRecord.data.id);
// select by index
grid.getSelectionModel().select(selectedIdx);
For some reason the grid.getSelectionModel().select(record) method wasn't working for me, but selecting by index seems to work.
Edit: found out why grid.getSelectionModel().select(record) method wasn't working. Apparently the store is reloaded, the record instances aren't the same (they have different automatically generated Ext IDs). You have to use selectAt() in this case.

Answer 4

for extjs 4.1.7 users
need a workarround about the statement in
refreshSelection() {
...
Ext.defer(this.setScrollTop, 30, this,
[this.getView().scrollState.top])
}
thus setScrollTop no longer exists
so a working soluction is add
me.getView().preserveScrollOnRefresh = true;
in initComponent
Ext.define('PersistantSelectionGridPanel', {
extend: 'Ext.grid.Panel',
selectedRecords: [],
initComponent: function() {
this.callParent(arguments);
this.getStore().on('beforeload', this.rememberSelection, this);
this.getView().on('refresh', this.refreshSelection, this);
//-------------------------------------------
me.getView().preserveScrollOnRefresh = true;
//-------------------------------------------
},
rememberSelection: function(selModel, selectedRecords) {
if (!this.rendered || Ext.isEmpty(this.el)) {
return;
}
this.selectedRecords = this.getSelectionModel().getSelection();
this.getView().saveScrollState();
},
refreshSelection: function() {
if (0 >= this.selectedRecords.length) {
return;
}
var newRecordsToSelect = [];
for (var i = 0; i < this.selectedRecords.length; i++) {
record = this.getStore().getById(this.selectedRecords[i].getId());
if (!Ext.isEmpty(record)) {
newRecordsToSelect.push(record);
}
}
this.getSelectionModel().select(newRecordsToSelect);
}
});

Answer 5

i have make modification on this code.
If you make selection, and aplys a filter on the store and reload it, the selection model have a first empty array in this selected collection ( at index 0 ).
This modification is in the last line of the "refreshSelection" function.
if (newRecordsToSelect.length >= 1){
this.getSelectionModel().select(newRecordsToSelect);
Ext.defer(this.setScrollTop, 30, this, [this.getView().scrollState.top]);
}