This article is the second part of the series:

This article is the second part of the series:

You may already be aware that DotVVM 4.0 has introduced a new feature called Composite Controls, which provides a new way to write controls in DotVVM. This approach eliminates the need to declare DotVVM properties in code-only controls, for which you had to use the dotprop code snippet and work with long property declaration blocks. Instead, it only requires declaring a `GetContents` method and placing individual control properties as arguments of the method. By using this approach, the control code appears much more attractive and readable.

Building forms is really easy! To put all selected options into a collection, just bind the collection to multiple CheckBox controls.

One of the scenarios in which the new way of building controls in DotVVM – the composite controls – really excel, is when used in combination with Web components.

Building forms is really easy! Use the Visible property to show or hide forms fields based on values in other fields.

Building forms is really easy! Bind a collection of objects in the ComboBox control and let the user select the value.

DotVVM syntax is different from Razor. The Validator control can display validation errors for a particular property. You can choose to apply CSS classes on any element based on validation state of some property.

DotVVM syntax is different from Razor. Instead of passing lambda expressions, use _root, _parent or _this expressions to reference different scopes in your viewmodel.

DotVVM syntax is different from Razor. Instead of concatenating fragments of CSS classes, just use class-* property and specify a boolean expression indicating whether the class shall be included or not.