Messagebox

Messagebox

• Demonstration: Messagebox
• Java API: Messagebox
• JavaScript API: N/A

Employment/Purpose

It provides a set of utilities to show a message and have a user to confirm a situation.

It is typically used to alert users when an error occurs, or to prompt users for an decision.

Example

The simplest use of a message box is to inform the user something is done. For example,

Messagebox.show("The backup has been done.");
Messagebox.show("Failed to access the information", null, 0,  Messagebox.ERROR);

There are a lot of utilities that allow you to show a message in different look, such as the buttons, icon and title. Please refer to Messagebox for more information.

Take Actions Depending On Which Button Is Clicked

If you'd like to know which button is clicked, you have to implement an event listener. For example,

Messagebox.show("Question is pressed. Are you sure?", 
	"Question", Messagebox.OK | Messagebox.CANCEL,
	Messagebox.QUESTION,
	 	new org.zkoss.zk.ui.event.EventListener(){
	 		public void onEvent(Event e){
	 			if(Messagebox.ON_OK.equals(e.getName())){
	 				alert("user click ok ");
	 			}else if(Messagebox.ON_CANCEL.equals(e.getName())){
	 				alert("user click cancel ");
	 			}
	 		}
	 	}
	);

The invocation of Messagebox.show(String, String, int, String) will return immediately after the invocation. Then, if the user clicks a button, the event listener will be invoked. You could examine the event name to know which button is clicked. If the user clicked the Close button on the right-top corner, the onClose event is fired.

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Customization

The Default Title

If the title is not specified in the application's name (returned by WebApp.getAppName()). You could change it by invoking WebApp.setAppName(String).

Since 5.0.6, you could specify the application's name with a library property called org.zkoss.zk.ui.WebApp.name. For example, you could specify the following in WEB-INF/zk.xml:

<library-property>
    <name>org.zkoss.zk.ui.WebApp.name</name>
    <value>My Killer Application</value>
</library-property>

The Template

The UI of a message box is based on a ZUL file, so you could customize it by replacing it with your own implementation. It can be done easily by invoking Messagebox.setTemplate(String). Notice that it affects all message boxes used in an application. It is typically called when the application starts (i.e., in WebAppInit.init(WebApp) -- for more information, please refer to ZK Developer's Reference: Init and Cleanup).

To implement a custom template, please take a look at the default template.

Supported events

Name	Event Type
None	None

Supported Children

*NONE

Use cases

Version	Description	Example Location

Version History

Version	Date	Content
6.0.0	October 2011	The order and labels of the buttons were assignable.
6.0.0	October 2011	Messagebox.ClickEvent was introduced to simplify the identification of a button.