SAP HANA XS Advanced - Consume the OData service in a basic HTML5 module

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SAP HANA XS Advanced - Consume the OData service in a basic HTML5 module

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SAP HANA XS Advanced - Consume the OData service in a basic HTML5 module

Thomas Jung

April 9, 2020

Created by

July 10, 2018

Beginner

15 min.

Use SAPUI5 as a micro-service to display data from an OData service

You will learn

How to perform a very simple addition to the default HTML5 module to consume the OData service by binding a model. This is a very simple example that will be later expanded to incorporate better practices and is only intended to demonstrate a basic test consumption of a data model and the basic troubleshooting tools.

Prerequisites

Create a Node.js module to expose an OData service (https://developers.sap.com/tutorials/xsa-xsjs-xsodata.html)

Step 1: Remove the default scripts

Open the file index.html under resources. You will find the default code creates a button that fades away when pressed

Remove the logic for the button

Done

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Step 2: Bind the OData model to a table

View Full Instructions

In this previous tutorial, you created an XSJS compatible Node.js module to expose an OData V2 service that provides data from your database module. Consuming that model using SAP UI5 is simplified thanks to the concept of binding.

Take a look at the output of the OData service in JSON format

Add the following script to your index.html file, where the logics for the button used to be.


<script>

	var oModel = new sap.ui.model.odata.v2.ODataModel("/xsodata/purchaseOrder.xsodata", true);
	var oTable = new sap.ui.table.Table({ title: "My first table" });
	oTable.addColumn(new sap.ui.table.Column({ label: "PO ID", template: "PURCHASEORDERID" }));
	oTable.setModel(oModel);
	oTable.bindRows("/POHeader");
	oTable.placeAt("uiArea");

	</script>

More about binding

You are using an OData model that will load data as required by the client and delegate the sorting and filtering operations to the server-side. This model will provide the data from the service you defined before. You are then creating a table and binding the model to the table, so that all changes in the data are reflected also in the table. Check the Help for more information about SAPUI5 and binding

Save and run the HTML5 module. You should get an error. Press F12 in your browser and look at the errors in the console.

What is the error message saying? sap not found Missing library Component.js has not been found That sap.ui.table.Table is not a constructor

Step 3: Add missing libraries

You can see the available libraries in the Sources tab in the panel. Notice the resources that are loaded:

Go back and look at the code in index.html .

You are using sap.ui.table and sap.ui.model to display the table. If you compare the libraries you are using to the libraries that are loaded, you will see sap.ui.table is not present as a resource. This is why you are getting the error in the console.

More about these libraries

You will see there is a reference to sap-ui-core.js, a control library (sap.m) and a theme, sap_bluecrystal.
sap-ui-core.js is the bootstrap file for SAPUI5, it contains the minimum required parts of the core library. This will load and initialize the SAPUI5 library as soon as the script is executed by the browser. After its initialization, and because it has been added by default in the index.html, the library sap.m is loaded, together with its dependencies.

Add sap.ui.table to the index.html file as a required library.

Save and run the web module again. You should see the table with results. Additionally, if you refresh while in the Network tab, you will see the requests, the sequence in which they are called and how long it takes them to load.

Done

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Step 4: Add the SAPUI5 service as a dependency

Just like with the UAA service, you want to bind the instance you have created to your Multi-Target Application. Open the MTA.yaml file and click add a new resource called ui5.

Use org.cloudfoundry.managed-service as the type and the following key-value pairs under parameters for HANA 2.0 SPS04 (for other releases, use the xs marketplace command to view the available service-plans):

service : sapui5_sb
service-plan : sapui5-1.60

Where are the values coming from?

The name of the service instance, the type of service and service plan are use to bind the instance of the UI5 service to the web module. You can see these values under Service Instances in the XS Advanced cockpit or by listing them using the XS CLI with command xs services

Save the yaml file and navigate to the resources tab. Use the drop-down menu to choose the newly created resource.

Done

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Step 5: Adjust the AppRouter replacement

View Full Instructions

Open the file xs-app.json and add the following code at the end of the route declarations

{
		"source": "/(.*)",
		"localDir": "resources",
		"authenticationType": "xsuaa",
		"replace": {
			"pathSuffixes": ["index.html", "odataTest.html"],
			"services": {
				"sapui5_sb": {
					"tag": "ui5"
					}
				}		
				}
			}

You will need to add a comma before adding the new route with the replacement values, the full file looks as follows:

Save the file

What does this mean?

Take a look at the package.json file. You will notice a node module,approuter.js, is called. This module will read the file xs-app.json, use the welcomeFile value to redirect to index.html by default, and interpret the routes requests should take according to the regular expressions in the source key.
It can also replace placeholders in static text resources, such as a placeholder for the URL to the UI5 service in index.html. In this case, the AppRouter finds the service with tag ui5 like you created in step 4, bound to the web application. If you use command xs env APP, where APP is the name of your web application, you will see the configuration details for the UI5 service.

You can find more information about the AppRouter in the SAP Help portal