Update Form Data Using the API

If you need to update form data at runtime, redefine the formData object. In this case, form item values are updated automatically and the widget is rerendered from scratch. In the following example, the SelectBox widget changes the formData object.

JavaScript
var employees = [{
    name: "John Heart",
    position: "CEO",
    officeNo: "901"
}, {
    name: "Bill Silver",
    position: "HR Manager",
    officeNo: "905"
}];

$(function() {
    var form = $("#formContainer").dxForm({
        formData: employees[0]
    }).dxForm("instance");

    $("#employeeSelector").dxSelectBox({
        displayExpr: "name",
        dataSource: employees,
        value: employees[0],
        onValueChanged: function(data) {
            form.option("formData", data.value);
        }
    });
});

The Form widget provides methods that update specific formData fields and rerender the corresponding editors without rerendering the whole widget. The updateData(dataField, value) method updates the value of a single field. The updateData(data) method updates values of several fields at once. In the following code, these methods are called on a Button click.

JavaScript
$(function() {
    var form = $("#formContainer").dxForm({
        formData: {
            firstName: "Joe",
            lastName: "Heart",
            phone: "+1(213) 555-9392"
        }
    }).dxForm("instance");

    $("#updatePhone").dxButton({
        text: 'Update the Phone Number',
        onClick: function () {
            form.updateData("phone", "+1(333) 888-7698");
        }
    });

    $("#updateName").dxButton({
        text: 'Update the Name',
        onClick: function () {
            form.updateData({
                firstName: "John",
                lastName: "Doe"
            });
        }
    });
});

With Angular, two-way binding to a component property is sufficient to update formData at runtime. Swapping the whole formData object rerenders the widget from scratch; updating specific formData fields rerenders only the corresponding editors.

HTML
TypeScript
<dx-form [(formData)]="employee"></dx-form>
<dx-button
    text="Update the Phone Number"
    (onClick)="employee.phone = '+1(333) 888-7698'">
</dx-button>
import { DxFormModule, DxButtonModule } from 'devextreme-angular';
// ...
export class AppComponent {
    employee = {
        firstName: "Joe",
        lastName: "Heart",
        phone: "+1(213) 555-9392"
    }
}
@NgModule({
    imports: [
        // ...
        DxFormModule,
        DxButtonModule
    ],
    // ...
})

View Demo

See Also