The Web Client block enables opening application screens via commands embedded into a URL. If the browser does not have an active application session with the registered user, the application will show the login screen first, and then, after successful authentication, proceed to the main application window with the requested screen.

The list of supported commands is defined in the cuba.web.linkHandlerActions application property. By default, these are open and o. When the HTTP request is being processed, the last part of the URL is analyzed, and if a match with one of the commands is detected, control is handed over to the LinkHandler bean. The standard implementation of this bean accepts the following parameters:

  • screen – name of the screen defined in screens.xml, for example:

  • item – an entity instance to be passed to the edit screen, encoded according to conventions of the EntityLoadInfo class, i.e. entityName-instanceId or entityName-instanceId-viewName. Examples:

  • params – parameters passed to the screen controller’s init() method. Parameters are encoded as name1:value1,name2:value2. Parameter values may include entity instances encoded according to the conventions of the EntityLoadInfo class. Examples:


LinkHandler bean may be redefined in the application project in order to provide specialized link handling. The LinkHandler bean is a prototype, so do not forget to specify the scope when defining your bean in spring.xml, for example:

<!-- web-spring.xml -->
<bean id="cuba_LinkHandler" class="" scope="prototype"/>