We need a composition layer for the GUI. It should combine the data from multiple services into one interactive web page. AngularJs comes to mind.

My next step in AngularJs (first step here) is to get data from multiple REST calls. The trigger is a button and the data is presented side-by-side.

First the HTML code. The button fires the getData function on data-ng-click. By using the selectedId in the function call the input is passed to the function.

<div ng-app="multiple" ng-controller="leftrightctrl">
  <div class="row">
    <input type="number" ng-model="selectedId" />
    <button data-ng-click="getData(selectedId)">Click me!</button>
  </div>
  <div class="row">
    <div class="col-md-6">
      <pre>November: {{left.name}}</pre>
    </div>
    <div class="col-md-6">
      <pre>December: {{right.name}}</pre>
    </div>
  </div>
</div>

In javascript I defined a function to get the left and the right. With getData I call both. The data is from a REST service. It is called with the id and a date. Left is november (2015-11-01) and right is december (2015-12-01).

angular
  .module('multiple', [])
  .controller('leftrightctrl', function ($scope, $http) {
    $scope.left = null;
    $scope.right = null;
    $scope.getLeft = function (id) {
     return $http.get("http://localhost/service/api/multiple/" + id + "/2015-11-01")
                 .then(function (response) {
                   $scope.left = response.data;
                 });
    };
    $scope.getRight = function (id) {
     return $http.get("http://localhost/service/api/multiple/" + id + "/2015-12-01")
                 .then(function (response) {
                   $scope.right = response.data;
                 });
    };
    $scope.getData = function (id) {
     $scope.getLeft(id);
     $scope.getRight(id);
    };
});

Reading code from others is the first step in shu-ha-ri. I’m learning.
plnkr with a live version of the code.