Beginner
SAP HANA XS Advanced - Consume the OData service in a basic HTML5 module
January 5, 2021
Created by
July 10, 2018
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
- This tutorial is designed for SAP HANA on premise and SAP HANA, express edition. It is not designed for SAP HANA Cloud.
- Proficiency: Beginner
- 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
Step 2: Bind the OData model to a table
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.
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.jsis 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 theindex.html, the librarysap.mis 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.
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 Instancesin the XS Advanced cockpit or by listing them using the XS CLI with commandxs services
Save the yaml file and navigate to the resources tab. Use the drop-down menu to choose the newly created resource.
Step 5: Adjust the AppRouter replacement
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.jsonfile. You will notice a node module,approuter.js, is called. This module will read the filexs-app.json, use thewelcomeFilevalue to redirect toindex.htmlby default, and interpret the routes requests should take according to the regular expressions in thesourcekey.
It can also replace placeholders in static text resources, such as a placeholder for the URL to the UI5 service inindex.html. In this case, theAppRouterfinds the service with tagui5like you created in step 4, bound to the web application. If you use commandxs 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
Step 6: Call the micro-service in your HTML file
Open the index.html file and replace the remote URL with the variable {{{sapui5_sb.url}}}.
Save and Run the index.html file.
Right-click on the site and use the view source option to see the replacement:
Press CTRL + SHIT + ALT + S and wait for the diagnostics window.