Cannot call method 'getODataModel' of undefined

Hi all, I am trying to call this statement in the onInit function:

this.oApplicationFacade.getODataModel().attachRequestCompleted(jQuery.proxy(this.onRequestCompleted,this));

onInit : function() {  jQuery.sap.require("sap.ca.scfld.md.ComponentBase");  this.oApplicationFacade.getODataModel().attachRequestCompleted(jQuery.proxy(this.onRequestCompleted,this));  .......    },

I am getting this error message: Uncaught TypeError: Cannot call method 'getODataModel' of undefined What went missing here?

Could someone give an example how to use it?

Thank you

Ferry