Demonstrates how to override back button (back navigation) on Windows 10 using WinJS

Winjs_override_back.js

// -----------------
// Override Namespace
// -----------------
WinJS.Namespace.define("override", {
  // Add events on the page
  init: WinJS.Class.define(function () {
    WinJS.Navigation.addEventListener("beforenavigate", this.beforenavigate);
  }),
  
  // Execute additional code before navigation
  beforenavigate: WinJS.Class.define(function (event) {
    // This function gives you a chance to veto navigation. This demonstrates that capability
    if (true /* should cancel navigation */) {
        event.preventDefault();
    }
  })
});


(function () {
  "use strict";

  WinJS.UI.Pages.define("override.html", {
    ready: function (element, options) {
      // TODO: Called when the page is 
      override.init();
    },

    unload: function () {
      // TODO: Fired when we navigate outside this page
    },

    updateLayout: function (element) {
      // TODO: Must be fired when the layout changes
    },
  });
})();