ZK Developer's Reference/Customization/UI Factory

UiFactory is used to instantiate all UI objects, such as session, desktop, and components, and to load ZUML documents. You could customize it to provide the functionality you want.

For example, SerializableUiFactory is the factory used to instantiate sessions that are serializable, while SimpleUiFactory, the default factory, instantiates non-serializable sessions.

Here are a list of customization you could do with UI Factory:

• Load a ZUML document from, say, a database
  • It can be done by overriding UiFactory.getPageDefinition(RequestInfo, String)
• Instantiate a component by using a different implementation
  • It can be done by overriding UiFactory.newComponent(Page, Component, ComponentInfo) and UiFactory.newComponent(Page, Component, ComponentInfo, String).
  • Instantiate a desktop by using a different implementation
  • It can be done by overriding UiFactory.newDesktop(RequestInfo, String, String)
  • Instantiate a page by using a different implementation
  • It can be done by overriding UiFactory.newPage(RequestInfo, PageDefinition, String) and/or UiFactory.newPage(RequestInfo, Richlet, String)

Notice that it is suggested to extend from either SerializableUiFactory or SimpleUiFactory, rather than to implement UiFactory from scratch.

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Load ZUML from Database

The default implementation of AbstractUiFactory.getPageDefinition(RequestInfo, String) loads the ZUML document from the Web application's resources (i.e., the files found in a Web application). If you prefer to load from other sources, such as a database, you could override it.

The pseudo code will look like the following:

public class MyUiFactory extends SimpleUiFactory {
    @Override
    public PageDefinition getPageDefinition(RequestInfo ri, String path) {
        PageDefinition pgdef = getFromCache(path); //your cache implementation
        if (pgdef == null) {
            String content = loadFromDatabase(path); //your resource loading
            pgdef = getPageDefinition(ri, content, "zul"); //delegate to SimpleUiFactory
            setCache(path, pgdef); //cache the result
        }
        return pgdef;
    }
}

where we assume you implemented loadFromDatabase to load the ZUML document from a database. In addition, you have to implement getFromCache and setCache to cache the result in order to improve the performance of retrieving the document from the database.

On the other hand, the parsing of the ZUML document can be done easily by calling AbstractUiFactory.getPageDefinitionDirectly(RequestInfo, String, String).