ZK User Interface Markup Language
This documentation is for an older version of ZK. For the latest one, please click here.
Overview
The ZK User Interface Markup Language (ZUML) is based on XML. ZUML file has filename extension : zul. Each ZK element instructs the ZK Loader which component to create. A ZK property describes an initial value to be assigned to the created component. A ZK processing instruction describes how to process the whole page, such as the page title.
Implicit Objects are much like global variables handled by system. You can use it to get information of system and client. Also, it's a way to pass information between pages. You'll find it really helpful in developing a web application.
Expresion Language let you access variables in intuitive way.
zscript let you write java code inside ZUML, for fast prototyping.
In section ZK Processing Instruction, we'll show how to use the most common directives to control page behavior, such like macro component.
In section ZK Attributes, we'll show attributes used to control the associated element, not just initializing the data member. It provides utilities like conditional evaluation(if), iterative evaluation(forEach), etc.
In section ZK Elements, we'll show useful elements that's not UI component, like zk element, zscript element.
After reading this chapter, you should be able to write your own ZUML pages easily.
- See Also
XML
- Elements Must Be Well-formed
- Special Character Must Be Replaced
- Attribute Values Must Be Specified and Quoted
- Comment by <-- -->
- Character Encoding
zscript
- Write Java code in ZUML
- Hints to read zscript
- Distinguish zscript from EL
- Java Interpreter (BeanShell)
- zscript other than Java
Implicit Objects
- Overview
- List of Implicit Objects
- Information about Request and Execution
- Lifecycle of page, execution, desktop, session, application
- About xxxScope
Expression Language (EL)
- Overview
- Access Java Bean
- Access ZUML Component
- Access Implicit Object
- More EL Examples
- Import Java Method's
ZK Processing Instructions
Directives to control whole page behavior
| page | Describes attributes of a page |
| component | Defines a new component for a particular page |
ZK Attributes
Act on component, such like conditional evaluation, iteration, load on demand.
| if | Conditional evaluation of an component |
| forEach, each | Iterative evaluate component against a collection |
| use, apply | Write event handling code in pure java file. apply support MVC pattern better. |
| forward | Let centralized controller handle events. |
ZK Elements
Helper component that's not UI. It helps to save variable, write java code in ZUML, and others.
| zk | Aggregate other components |
| zscript | Write java code in ZUML |
| attribute | Make the page more readable |
| variables | Store variable in namespace scope |
| custom-attributes | Store variables in different scopes |
Component Sets and XML Namespaces