Integrate Real-Time Access to AlloyDB in SAPUI5 MVC Apps

In this article we show how to use the CData API Server and with the ADO.NET Provider for AlloyDB (or any of 200+ other ADO.NET Providers) to write SAPUI5 apps that leverage the capabilities of the AlloyDB API, without writing to a back-end database. The API Server is a lightweight Web application that runs on your server and produces OData feeds of AlloyDB data. OData is the standard for real-time data access over the Web and has built-in support in SAPUI5 and OpenUI5.

Set Up the API Server

Follow the steps below to begin producing secure AlloyDB OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to AlloyDB

After you deploy the API Server and the ADO.NET Provider for AlloyDB, provide authentication values and other connection properties needed to connect to AlloyDB by clicking Settings -> Connections and adding a new connection in the API Server administration console.

The following connection properties are usually required in order to connect to AlloyDB.

• Server: The host name or IP of the server hosting the AlloyDB database.
• User: The user which will be used to authenticate with the AlloyDB server.
• Password: The password which will be used to authenticate with the AlloyDB server.

You can also optionally set the following:

• Database: The database to connect to when connecting to the AlloyDB Server. If this is not set, the user's default database will be used.
• Port: The port of the server hosting the AlloyDB database. This property is set to 5432 by default.

Authenticating with Standard Authentication

Standard authentication (using the user/password combination supplied earlier) is the default form of authentication.

No further action is required to leverage Standard Authentication to connect.

Authenticating with pg_hba.conf Auth Schemes

There are additional methods of authentication available which must be enabled in the pg_hba.conf file on the AlloyDB server.

Find instructions about authentication setup on the AlloyDB Server here.

Authenticating with MD5 Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to md5.

Authenticating with SASL Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to scram-sha-256.

Authenticating with Kerberos

The authentication with Kerberos is initiated by AlloyDB Server when the ∏ is trying to connect to it. You should set up Kerberos on the AlloyDB Server to activate this authentication method. Once you have Kerberos authentication set up on the AlloyDB Server, see the Kerberos section of the help documentation for details on how to authenticate with Kerberos.

You can then choose the AlloyDB entities you want to allow the API Server access to by clicking Settings -> Resources. This article uses Orders as an example.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. You can authenticate as well as encrypt connections with SSL. Access can also be restricted by IP address; Access is restricted to only the local machine by default.

Create the View

In this article the user views and interacts with AlloyDB data through an SAPUI5 table control. Table columns will be automatically detected from the metadata retrieved from the API Server's API endpoint. We define the following table in a separate View.view.xml file:

<mvc:View
  controllerName="sap.ui.table.sample.OData2.Controller"
  xmlns="sap.ui.table"
  xmlns:mvc="sap.ui.core.mvc"
  xmlns:u="sap.ui.unified"
  xmlns:c="sap.ui.core"
  xmlns:m="sap.m">
  <m:Page
    showHeader="false"
    enableScrolling="false"
    class="sapUiContentPadding">
    <m:content>
      <Table
        id="table"
        selectionMode="MultiToggle"
        visibleRowCount="10"
        enableSelectAll="false"
        rows="{/Orders}"
        threshold="15"
        enableBusyIndicator="true"
        columns="{
          path: 'meta>/dataServices/schema/[${namespace}===\'CData\']/entityType/[${name}===\'Orders\']/property',
          factory: '.columnFactory'
        }">
        <toolbar>
          <m:Toolbar>
            <m:Title text="AlloyDB Orders"></m:Title>
          </m:Toolbar>
        </toolbar>
        <noData>
          <m:BusyIndicator class="sapUiMediumMargin"/>
        </noData>
      </Table>
    </m:content>
  </m:Page>
</mvc:View>

Create the Model and Controller

In SAPUI5, you do not need to write any OData queries; an ODataModel instance handles the application's data access commands. The API Server then translates the queries into AlloyDB API calls.

The controller processes user input and represents information to the user through a view. Define the controller in a new file, Controller.controller.js. Instantiate the model in the onInit function -- you will need to replace the placeholder values for the URL to the API Server, a user allowed to access the OData endpoint of the API Server, and the authtoken for the user.

sap.ui.define([
  "sap/ui/core/mvc/Controller",
  "sap/ui/model/odata/v2/ODataModel",
  "sap/ui/model/json/JSONModel",
  "sap/ui/table/Column",
  "sap/m/Text",
], function(Controller, ODataModel, JSONModel, Column, Text ) {
  "use strict";
  

  return Controller.extend("sap.ui.table.sample.OData2.Controller", {
    
    onInit : function () {
      
      var oView = this.getView();
      var oDataModel = new ODataModel("http://myserver/api.rsc/",{user: "MyUser", password: "MyAuthToken"});
      
      oDataModel.getMetaModel().loaded().then(function(){
        oView.setModel(oDataModel.getMetaModel(), "meta");
      });
      oView.setModel(oDataModel);
      
      var oTable = oView.byId("table");
      var oBinding = oTable.getBinding("rows");
      var oBusyIndicator = oTable.getNoData();
      oBinding.attachDataRequested(function(){
      oTable.setNoData(oBusyIndicator);
      });
      oBinding.attachDataReceived(function(){
        oTable.setNoData(null); //use default again ("no data" in case no data is available)
      });
    },
    
    onExit : function () {
    },
    
    columnFactory : function(sId, oContext) {
      var oModel = this.getView().getModel();
      var sName = oContext.getProperty("name");
      var sType = oContext.getProperty("type");
      var iLen = oContext.getProperty("maxLength");
      iLen = iLen ? parseInt(iLen, 10) : 10;
      
      return new Column(sId, {
        sortProperty: sName, 
        filterProperty: sName,
        width: (iLen > 9 ? (iLen > 50 ? 15 : 10) : 5) + "rem",
        label: new sap.m.Label({text: "{/#Orders/" + sName + "/@name}"}),
        hAlign: sType && sType.indexOf("Decimal") >= 0 ? "End" : "Begin",
        template: new Text({text: {path: sName}})
      });
    }
    
  });

});

Describe Application Logic

Create a component that contains the resources of your application. Define the following in Component.js:

sap.ui.define([
  'sap/ui/core/UIComponent'
], function(UIComponent) {
  "use strict";

  return UIComponent.extend("sap.ui.table.sample.OData2.Component", {
    metadata : {
      rootView : "sap.ui.table.sample.OData2.View",
      dependencies : {
        libs : [
          "sap.ui.table",
          "sap.ui.unified",
          "sap.m"
        ]
      },

      config : {
        sample : {
          stretch : true,
          files : [
            "View.view.xml",
            "Controller.controller.js"
          ]
        }
      }
    }
  });

});

Bootstrap OpenUI5 and Launch

To complete the MVC application, simply add the bootstrap and initialization code. Add these directly to index.html:

<!DOCTYPE HTML>

<html>
<head>
  <meta http-equiv="x-ua-compatible" content="ie=edge">
  <meta charset="utf-8"> 
  <title>AlloyDB Orders</title>
  
  <script id="sap-ui-bootstrap"
    src="https://openui5.hana.ondemand.com/resources/sap-ui-core.js"
    data-sap-ui-libs="sap.m"
    data-sap-ui-theme="sap_bluecrystal"
    data-sap-ui-xx-bindingSyntax="complex"
    data-sap-ui-preload="async"
    data-sap-ui-compatVersion="edge" 
    data-sap-ui-resourceroots='{"sap.ui.table.sample.OData2": "./", "sap.ui.demo.mock": "mockdata"}'>
  </script>
  
  <!-- application launch configuration -->
  <script>
  
      sap.ui.getCore().attachInit(function() {
        new sap.m.App ({
          pages: [
                new sap.m.Page({
                    title: "AlloyDB Orders", 
                    enableScrolling : false,
                  content: [ new sap.ui.core.ComponentContainer({
                  height : "100%", name : "sap.ui.table.sample.OData2"
                })]
            })
          ]
      }).placeAt("content");
    });

  </script>
</head> 
  <!-- UI Content -->
<body class="sapUiBody" id="content" role="application">
</body> 
</html>

The resulting SAPUI5 table control reflects any changes to a table in the remote AlloyDB data. You can now browse and search current AlloyDB data.