Step 20: Data Types

The list of invoices is already looking nice, but what is an invoice without a price assigned? Typically prices are stored in a technical format and with a '.' delimiter in the data model. For example, our invoice for pineapples has the calculated price 87.2 without a currency. We are going to use the OpenUI5 data types to format the price properly, with a locale-dependent decimal separator and two digits after the separator.

Preview

^{The list of invoices with prices and number units}

You can access the live preview by clicking on this link: 🔗 Live Preview of Step 20.

To download the solution for this step as a zip file, just choose the link here: 📥 Download Solution for Step 20.

Coding

webapp/controller/InvoiceList.controller.js (New)

We want to display in our list view the price in Euro, and typically the currency is part of our data model on the back end. In our case this is not the case, so we need to define it directly in the app. We therefore create a controller for the invoice list and define a view model for the currency code for Euro. It is a simple JSON model with just one key currency and the value EUR.

import Controller from "sap/ui/core/mvc/Controller";
import JSONModel from "sap/ui/model/json/JSONModel";

/**
 * @namespace ui5.walkthrough.controller
 */
export default class App extends Controller {
    
    onInit(): void {
        const viewModel = new JSONModel({
            currency: "EUR"
        });
        this.getView()?.setModel(viewModel, "view");        
    } 
};

webapp/view/InvoiceList.view.xml

We add the invoice list controller to the view to get access to the view model we defined in the controller.

We add a price and the currency to our invoices list in the view by adding the number attribute to the ObjectListItem control, then we apply the currency data type on the number by setting the type attribute of the binding syntax to sap.ui.model.type.Currency. The Currency type will handle the formatting of the price for us, based on the currency code. In our case, the price is displayed with 2 decimals.

Additionally, we set the formatting option showMeasure to false. This hides the currency code in the property number. Instead we pass the currency on to the ObjectListItem control as a separate property numberUnit.

<mvc:View
   controllerName="ui5.walkthrough.controller.InvoiceList"
   xmlns="sap.m"
   xmlns:mvc="sap.ui.core.mvc">
   <List
      headerText="{i18n>invoiceListTitle}"
      class="sapUiResponsiveMargin"
      width="auto"
      items="{invoice>/Invoices}" >
      <items>
         <ObjectListItem
            title="{invoice>Quantity} x {invoice>ProductName}"
            number="{
               parts: [
                  'invoice>ExtendedPrice', 
                  'view>/currency'
               ],
               type: 'sap.ui.model.type.Currency',
               formatOptions: {
                  showMeasure: false
               }
            }"
            numberUnit="{view>/currency}"/>
      </items>
   </List>
</mvc:View>

As you can see above, we are using a special binding syntax for the number property of the ObjectListItem. This binding syntax makes use of so-called "Calculated Fields", which allows the binding of multiple properties from different models to a single property of a control. The properties bound from different models are called “parts”. In the example above, the property of the control is number and the bound properties (“parts”) retrieved from two different models are invoice>ExtendedPrice and view>/currency.