Integrate Real-Time Access to Lakebase in SAPUI5 MVC Apps

Jerod Johnson
Director, Technology Evangelism

Use the built-in ODataModel class in SAPUI5 to create Web apps that reflect changes to Lakebase data in real time.

In this article we show how to use the CData API Server to write SAPUI5 apps that leverage the capabilities of the Lakebase 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 Lakebase 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

If you have not already done so, download the CData API Server. Once you have installed the API Server, follow the steps below to begin producing secure Lakebase OData services:

Connect to Lakebase

To work with Lakebase data from SAPUI5, we start by creating and configuring a Lakebase connection. Follow the steps below to configure the API Server to connect to Lakebase data:

First, navigate to the Connections page.
Click Add Connection and then search for and select the Lakebase connection.
Enter the necessary authentication properties to connect to Lakebase. To connect to Databricks Lakebase, start by setting the following properties:
- DatabricksInstance: The Databricks instance or server hostname, provided in the format instance-abcdef12-3456-7890-abcd-abcdef123456.database.cloud.databricks.com.
- Server: The host name or IP address of the server hosting the Lakebase database.
- Port (optional): The port of the server hosting the Lakebase database, set to 5432 by default.
- Database (optional): The database to connect to after authenticating to the Lakebase Server, set to the authenticating user's default database by default.
OAuth Client Authentication

To authenicate using OAuth client credentials, you need to configure an OAuth client in your service principal. In short, you need to do the following:
1. Create and configure a new service principal
2. Assign permissions to the service principal
3. Create an OAuth secret for the service principal
For more information, refer to the Setting Up OAuthClient Authentication section in the Help documentation.

OAuth PKCE Authentication

To authenticate using the OAuth code type with PKCE (Proof Key for Code Exchange), set the following properties:
- AuthScheme: OAuthPKCE.
- User: The authenticating user's user ID.
For more information, refer to the Help documentation.
After configuring the connection, click Save & Test to confirm a successful connection.

Configure API Server Users

Next, create a user to access your Lakebase data through the API Server. You can add and configure users on the Users page. Follow the steps below to configure and create a user:

On the Users page, click Add User to open the Add User dialog.
Next, set the Role, Username, and Privileges properties and then click Add User.
An Authtoken is then generated for the user. You can find the Authtoken and other information for each user on the Users page:

Creating API Endpoints for Lakebase

Having created a user, you are ready to create API endpoints for the Lakebase tables:

First, navigate to the API page and then click Add Table .
Select the connection you wish to access and click Next.
With the connection selected, create endpoints by selecting each table and then clicking Confirm.

Gather the OData Url

Having configured a connection to Lakebase data, created a user, and added resources to the API Server, you now have an easily accessible REST API based on the OData protocol for those resources. From the API page in API Server, you can view and copy the API Endpoints for the API:

Create the View

In this article the user views and interacts with Lakebase 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="Lakebase 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 Lakebase 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>Lakebase 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: "Lakebase 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 Lakebase data. You can now browse and search current Lakebase data.

A table in SAPUI5 that reflects changes to the data in real time. (Salesforce is shown.)

Ready to get started?

Learn more or sign up for a free trial:

CData API Server

CData is the data layer that makes AI work in production—live connectivity and replication across hundreds of the most critical enterprise sources, semantic context, and built-in governance. Powering AI for Databricks, Microsoft, Google, Palantir, and 10,000+ customers worldwide.