Step 12: Aggregation Binding Using Templates

Aggregation binding allows a control to be bound to a list within the model data and allows relative binding to the list entries by its child controls.

It will automatically create as many child controls as are needed to display the data in the model using one of the following two approaches:

Use template control that is cloned as many times as needed to display the data.
Use a factory function to generate the correct control per bound list entry based on the data received at runtime.

Preview

Figure 1: List with aggregation binding

Coding

You can view and download all files in the Explored app in the Demo Kit under Data Binding - Step 12.

webapp/index.html

... 
    // ----------------------------------------------------------------------
      var oProductModel = new sap.ui.model.json.JSONModel();
      oProductModel.loadData("./model/Products.json");
      sap.ui.getCore().setModel(oProductModel, "products");

webapp/view/App.view.xml

...
            <attributes>
              <ObjectAttribute text="{ path: 'Status', formatter: '.formatStatusText' }"/>
            </attributes>
          </ObjectListItem>
        </items>
      </List>
    </content>
  </Panel>
  <Panel headerText="{i18n>panel3HeaderText}" class="sapUiResponsiveMargin" width="auto">
    <content>
      <List headerText="{i18n>productListTitle}" items="{products>/Products}">
        <items>
          <ObjectListItem title="{products>ProductName}"
              number="{ parts: [{path: 'products>UnitPrice'},
                                {path: '/currencyCode'}],
                        type: 'sap.ui.model.type.Currency',
                        formatOptions: { showMeasure: false }
                      }"
              numberUnit="{/currencyCode}">
              <attributes>
                  <ObjectAttribute text="({products>QuantityPerUnit})" />
                  <ObjectAttribute title="{path: 'i18n>stockValue'}"
                                   text="{parts: [{path: 'products>UnitPrice'},
                                                  {path: 'products>UnitsInStock'},
                                                  {path: '/currencyCode'}],
                                          formatter: '.formatStockValue' }" />
              </attributes>
          </ObjectListItem>
        </items>
      </List>
    </content>
  </Panel>
</mvc:View>

We add a new panel to the view.

webapp/controller/App.controller.js

...
  formatStockValue: function(fUnitPrice, iStockLevel, sCurrCode) {
      var sBrowserLocale = sap.ui.getCore().getConfiguration().getLanguage();
      var oLocale        = new sap.ui.core.Locale(sBrowserLocale);
      var oLocaleData    = new sap.ui.core.LocaleData(oLocale);
      var oCurrency      = new sap.ui.model.type.Currency(oLocaleData.mData.currencyFormat);
      return oCurrency.formatValue([fUnitPrice * iStockLevel, sCurrCode], "string");
  };

webapp/model/Products.json (New)

{ "Products": [ {
     "ProductID": 1,
     "ProductName": "Chai",
     "SupplierID": 1,
     "CategoryID": 1,
     "QuantityPerUnit": "10 boxes x 20 bags",
     "UnitPrice": "18.0000",
     "UnitsInStock": 39,
     "UnitsOnOrder": 0,
     "ReorderLevel": 10,
     "Discontinued": false
    }, {
     "ProductID": 2,
     "ProductName": "Chang",
     "SupplierID": 1,
     "CategoryID": 1,
     "QuantityPerUnit": "24 - 12 oz bottles",
     "UnitPrice": "19.0000",
     "UnitsInStock": 17,
     "UnitsOnOrder": 40,
     "ReorderLevel": 25,
     "Discontinued": true
    }, {
     "ProductID": 3,
     "ProductName": "Aniseed Syrup",
     "SupplierID": 1,
     "CategoryID": 2,
     "QuantityPerUnit": "12 - 550 ml bottles",
     "UnitPrice": "10.0000",
     "UnitsInStock": 0,
     "UnitsOnOrder": 70,
     "ReorderLevel": 25,
     "Discontinued": false
    }, {
     "ProductID": 4,
     "ProductName": "Chef Anton's Cajun Seasoning",
     "SupplierID": 2,
     "CategoryID": 2,
     "QuantityPerUnit": "48 - 6 oz jars",
     "UnitPrice": "22.0000",
     "UnitsInStock": 53,
     "UnitsOnOrder": 0,
     "ReorderLevel": 0,
     "Discontinued": false
    }, {
     "ProductID": 5,
     "ProductName": "Chef Anton's Gumbo Mix",
     "SupplierID": 2,
     "CategoryID": 2,
     "QuantityPerUnit": "36 boxes",
     "UnitPrice": "21.3500",
     "UnitsInStock": 0,
     "UnitsOnOrder": 0,
     "ReorderLevel": 0,
     "Discontinued": true
    }]
  }

We now use a new JSON model file for product data.

webapp/i18n/i18n.properties

... 
# Screen titles
panel1HeaderText=Data Binding Basics
panel2HeaderText=Adress Details
panel3HeaderText=Aggregation Binding

# Invoice List
invoiceListTitle=Invoices
statusA=New
statusB=In Progress
statusC=Done

# Error messages
invalidDate=Invalid Date Format

# Product list
productListTitle=Product List
stockValue=Current Stock Value

webapp/i18n/i18n_de.properties

...
# Screen titles
panel1HeaderText=Data Binding Basics
panel2HeaderText=Adressdetails
panel3HeaderText=Aggregation Binding

# Invoice List
invoiceListTitle=Rechnungen
statusA=Neu
statusB=Laufend
statusC=Abgeschlossen

# Error messages
invalidDate=Ungültiges Datumsformat

# Product list
productListTitle=Artikelliste
stockValue=Lagerbestand Wert

We add the missing texts.