You should config to listen to beforedrop and drop events on TreeView not TreePanel.
Code:
var treePanel = Ext.create('Ext.tree.Panel', {
renderTo: 'our-tree',
height:600,
columns: [{
xtype: 'treecolumn',
text: 'Name',
dataIndex: 'text',
width: 300
},{
text: 'Description',
dataIndex: 'desc',
width: 500
}],
// listeners: {
// beforedrop: function(node, data, overModel, dropPosition, dropFunction, eOpts ) {
// var ajaxRequest= new htmldb_Get(..); ..
// }
// },
viewConfig: {
plugins: {
ptype: 'treeviewdragdrop'
},
listeners: {
beforedrop: function(node, data, overModel, dropPosition, dropFunction, eOpts ) {
console.log('beforedrop')
}
}
}
});