Dynamic binding of items in sap.m.Table using JS views

Question

HI,
I am developing a master detail page for a Purchase Order application. In master page, i display the list of Purchase Orders & on clicking the PO, i should display the detail page.
We use different ODATA models for Master & detail page. I am able to successfully list the POs in master page & i am struggling on the part where i have to pass the selected PO number to the new ODATA service URL & then display the details in a table.
Below is the code i use on TAP of Purchase order from master page:
tap: function(oEvent)
      sap.ui.getCore().byId("PODetailstable_nodata_id").setVisible(false);
      var oContext=oEvent.getSource().getBindingContext();
      var odataModel_PO_detail = new sap.ui.model.odata.ODataModel(detailServiceUrl,false,  "dev_sde", "28aug@2013");
      odataModel_PO_detail.setCountSupported(false);
      var tappedPONumber= oContext.getProperty("PONumber");
      var path = "/POHeaderSet('"+tappedPONumber+"')/HDRtoITM";
      PO_DetailsPage.setBindingContext(oContext);
      sap.ui.getCore().byId("po_details_table_id").setModel(odataModel_PO_detail);
      sap.ui.getCore().byId("po_details_table_id").bindContext(path);
      sap.ui.getCore().byId("po_details_table_id").setVisible(true);
And below is the code of my Detail page & the table: I set the bindcontext with new path at "tap" function in master page, i also do bindaggregation for the table with the new path.
The issue is i am able to HIT the new service URL, but no data is displayed. There is also a demo application on the same, but w/o source code it doesnt help me much in resolving this issue.
var PODetailstable_nodata = new sap.m.Table("PODetailstable_nodata_id",{title : "No Data"});
  var po_details_table =  new sap.m.Table("po_details_table_id", {
  inset: true,
         headerText: "table for Detail page",
         columns: [
                   new sap.m.Column({
                       header: new sap.m.Label({ text: "PO Number" })       }),
                   new sap.m.Column({ header: new sap.m.Label({ text: "Vendor" }) }),
                   new sap.m.Column({
                       header: new sap.m.Label({ text: "Vendor Name" })  }),
  var oTemplate = new sap.m.ColumnListItem({
            cells: [
                    new sap.m.Text({ text: "{PoNumber}" }),
                    new sap.m.Text({ text: "{Vendor}" }),
                    new sap.m.Text({ text: "{VendorName}"})
  po_details_table.bindAggregation("items", {
         path:"/POHeaderSet('"+"{PONumber}"+"')/HDRtoITM",
         template: oTemplate
  var PO_DetailsPage = new sap.m.Page("PO_DetailsPage_id",
  // title : "Purchase Order Details",
  title :  "{PoNumber}",
  content : [
           PODetailstable_nodata,
           po_details_table,
    footer : new sap.m.Bar
       contentRight: [
                      new sap.m.Button({
                      text : "Approve",
                      //press: oController.approve_pr,

Answer 1

I have modified my code by referring another forum,
on Tap, i now invoke a method from controller to update the binding i.e to pass the clicked PO number to the context.
updateBinding: function(oEvent)
  alert("updatebinding");
  var detailServiceUrl = "http://incas1054.ind.cldsvc.accenture.com:8000/sap/opu/odata/sap/ZPURCHASE_PAY_SRV";
  var odataModel_PO_detail = new sap.ui.model.odata.ODataModel(detailServiceUrl,false,  "dev_sde", "28aug@2013");
  odataModel_PO_detail.setCountSupported(false);
  var tableView=sap.ui.getCore().byId("po_details_table_id");
  tableView.setModel(odataModel_PO_detail);
  alert(tableView.getModel());
  var oContext = tableView.getBindingContext();
  //tableView.bindContext("/POHeaderSet");
  alert(oContext);
  var path=  oContext.sPath + "/HDRtoITM";
  var oTemplate = new sap.m.ColumnListItem({
            cells: [
                    new sap.m.Text({ text: "{PoNumber}" }),
                    new sap.m.Text({ text: "{Vendor}" }),
                    new sap.m.Text({ text: "{VendorName}"})
  tableView.bindItems(path, oTemplate);
Now, i see the PO number is set in the context, but i want to set a different context for details page as i hit different URL, Can anyone suggest on how to set a different context for details page & then pass the PO number from master to detail page?