When to use curly bracket in data binding?

Question

In the demo kit of openui5, the section Element Binding involves two forms of data binding implementation.

As in the code below:

var oMatrixLayout = new sap.ui.commons.layout.MatrixLayout();
oMatrixLayout.bindElement("/company");
oMatrixLayout.createRow(
	new sap.ui.commons.Label({text: "Name:"}),
	new sap.ui.commons.TextField({value: "{name}"})
);

oMatrixLayout.createRow(
	new sap.ui.commons.Label({text: "Revenue:"}),
	new sap.ui.commons.TextField({value: "{revenue}"})
);
oMatrixLayout.createRow(
	new sap.ui.commons.Label({text: "Employees:"}),
	new sap.ui.commons.TextField({value: "{employees}"})
);

When specifying the values for text fields, we use curly brackets({}) to indicate the value is from the model. However, in the code that immediately follows this one, no curly brackets are used:

var data = {clients:[{firstName:"Donald", lastName:"Duck"}]};
...// create and set model here
var oLabel = new sap.ui.commons.Label("myLabel");
oLabel.bindProperty("text", "firstName");
oLabel.bindElement("/clients/0");

As you can see, no curly brackets are used in oLabel.bindProperty("text", "firstName");
So, what's the difference between the two examples? When to use curly brackets in data binding and when not?

Sunil B N Sunil B N · Accepted Answer · 2015-07-07T03:50:01

When to use brackets?

While defining the controls along with the property use brackets: (binding at RUNTIME)

Example: new sap.ui.commons.TextField({value: "{name}"})

and in terms of XML <Label text="{name}"/>

When not to use brackets? // binding at a later time

whenever you're using bindProperty method.

When to use curly bracket in data binding?

1 Answers