Integrate Real-Time Access to Coinbase in SAPUI5 MVC Apps



Use the built-in ODataModel class in SAPUI5 to create Web apps that reflect changes to Coinbase 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 Coinbase 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 Coinbase 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 Coinbase OData services:

Connect to Coinbase

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

  1. First, navigate to the Connections page.
  2. Click Add Connection and then search for and select the Coinbase connection.
  3. Enter the necessary authentication properties to connect to Coinbase.

    Start by setting the Profile connection property to the location of the Coinbase Profile on disk (e.g. C:\profiles\Coinbase.apip). Next, set the ProfileSettings connection property to the connection string for Coinbase (see below).

    Coinbase API Profile Settings

    Coinbase uses OAuth-based authentication.

    First you need to register an OAuth app with Coinbase. This is done from your account under 'Settings' > 'API Access' > 'New OAuth2 Application'.

    After setting the following connection properties, you are ready to connect:

    • AuthScheme: Set this to OAuth.
    • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage the process to obtain the OAuthAccessToken.
    • OAuthClientId: Set this to the ClientID that is specified in you app settings.
    • OAuthClientSecret: Set this to the ClientSecret that is specified in you app settings.
    • CallbackURL: Set this to the Redirect URI you specified in your app settings.
  4. After configuring the connection, click Save & Test to confirm a successful connection.

Configure API Server Users

Next, create a user to access your Coinbase 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:

  1. On the Users page, click Add User to open the Add User dialog.
  2. Next, set the Role, Username, and Privileges properties and then click Add User.
  3. 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 Coinbase

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

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

Gather the OData Url

Having configured a connection to Coinbase 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 Coinbase 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="{/Deposits}"
        threshold="15"
        enableBusyIndicator="true"
        columns="{
          path: 'meta>/dataServices/schema/[${namespace}===\'CData\']/entityType/[${name}===\'Deposits\']/property',
          factory: '.columnFactory'
        }">
        <toolbar>
          <m:Toolbar>
            <m:Title text="Coinbase Deposits"></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 Coinbase 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: "{/#Deposits/" + 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>Coinbase Deposits</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: "Coinbase Deposits", 
                    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 Coinbase data. You can now browse and search current Coinbase data.

Ready to get started?

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CData API Server