ExtJS: remove a grid from a tabpanel when its underlying store is empty

Question

Hi,

I have TabPanel which contains, among other things, a Grid connected to a Store.

Several events may remove elements from the store.

I would like the Grid to be removed from the TabPanel when the store is empty and, possibly, to have a single place in my code to check for this event.

I thought about using store listeners, but unfortunately this causes exceptions in Ext code. My assumption is that this happens because rendering is performed on the grid after this is removed from the tabpanel.

Any idea on how to accomplish such a task without messing up Ext is much appreciated. Thanks :)

By the way, this is a code excerpt:

var myStore = new Ext.data.Store({
 reader: new Ext.data.JsonReader({fields: MyRecord}),
 listeners:{
  'clear': function(store, recs) {
   myTabPanel.remove(myGrid);
  },
  'remove': function(store, rec, idx) {
   if (store.getCount() == 0) {
    myTabPanel.remove(myGrid);
   }
  }
 }
});

var myGrid = new Ext.grid.GridPanel({
 id: "myGrid",
 title: "A Grid",
 store: myStore,
 frame:false,
 border:false,
 columns: [
 {
  header: 'Remove',
  align:'center',
  width: 45,
  sortable: false,
  renderer: function(value, metaData, record, rowIndex, colIndex, store) {
   return '<img src="images/remove.png" width="34" height="18"/>';
  }
 },{
  header: 'Some Data',
  dataIndex: 'data',
  sortable: true
 }
 ],
 listeners:{
  'cellclick':function(grid, rowIndex, colIndex, e){
   var rec = myStore.getAt(rowIndex);
   if(colIndex == 0){
    myStore.remove(rec);
   }
  }
 } 
});

var myTabPanel= new Ext.TabPanel({ 
 activeTab: 0,
 items: [ fooPanel, barPanel, myGrid]
});

Answer 1

Any reason that you are physically removing the grid from the tab? Seems like an odd UI paradigm -- why not just keep the empty grid with an "empty" message?

At any rate, I think your approach (using store events and record count to determine when to remove it) is basically OK. You might want to figure out how to solve whatever errors you say you were getting. What were they?

Answer 2

Problem solved: I just had to remove the grid setting the "autoDestroy" parameter to "false". Fixed code below.

var myStore = new Ext.data.Store({
 reader: new Ext.data.JsonReader({fields: MyRecord}),
 listeners:{
  'clear': function(store, recs) {
   myTabPanel.remove(myGrid, false);
  },
  'remove': function(store, rec, idx) {
   if (store.getCount() == 0) {
    myTabPanel.remove(myGrid, false);
   }
  }
 }
});

var myGrid = new Ext.grid.GridPanel({
 id: "myGrid",
 title: "A Grid",
 store: myStore,
 frame:false,
 border:false,
 columns: [
 {
  header: 'Remove',
  align:'center',
  width: 45,
  sortable: false,
  renderer: function(value, metaData, record, rowIndex, colIndex, store) {
   return '<img src="images/remove.png" width="34" height="18"/>';
  }
 },{
  header: 'Some Data',
  dataIndex: 'data',
  sortable: true
 }
 ],
 listeners:{
  'cellclick':function(grid, rowIndex, colIndex, e){
   var rec = myStore.getAt(rowIndex);
   if(colIndex == 0){
    myStore.remove(rec);
   }
  }
 } 
});

var myTabPanel= new Ext.TabPanel({ 
 activeTab: 0,
 items: [ fooPanel, barPanel, myGrid]
});