Chapter 5: Handling User Input

Target Application

This chapter we will demonstrate a common scenario: collecting user input in form-based page. The target application looks as follows:

There is a personal profile form with 5 different fields. Click the "Save" button saves users input and click the "Reload" button loads previous saved data back to the form. We will show how to implement these functions in both MVC and MVVM approach.

MVC Approach

Under this approach, we implement all event handling and presentation logic in a composer instead of in <zscript/> and make a zul clear from codes. This approach make the responsibility of each role (Model, View, and Controller) more cohesive and allows you to control components directly. It is very intuitive and very flexible.

View

With the concept and technique we talked in last chapter, it should be easy to construct a form like user interface as follows. The zul file below is included in the Center of the Border Layout.

chapter5/profile-mvc.zul

<?link rel="stylesheet" type="text/css" href="/style.css"?>
<window apply="org.zkoss.tutorial.chapter5.mvc.ProfileViewController" 
	border="normal" hflex="1" vflex="1" contentStyle="overflow:auto">
	<caption src="/imgs/profile.png" sclass="fn-caption" label="Profile (MVC)"/>
	<vlayout>
		<grid width="500px">
			<columns>
				<column align="right" hflex="min"/>
				<column/>
			</columns>
			<rows>
				<row>
					<cell sclass="row-title">Account :</cell>
					<cell><label id="account"/></cell>
				</row>
				<row>
					<cell sclass="row-title">Full Name :</cell>
					<cell>
						<textbox id="fullName" constraint="no empty: Plean enter your full name" width="200px"/>
					</cell>
				</row>
				<row>
					<cell sclass="row-title">Email :</cell>
					<cell>
						<textbox id="email" 
						constraint="/.+@.+\.[a-z]+/: Please enter an e-mail address" width="200px"/>
					</cell>
				</row>
				<row>
					<cell sclass="row-title">Birthday :</cell>
					<cell><datebox id="birthday" constraint="no future" width="200px"/></cell>
				</row>
				<row>
					<cell sclass="row-title">Country :</cell>
					<cell>
						<listbox id="country" mold="select" width="200px">
							<template name="model">
								<listitem label="${each}" />
							</template>
						</listbox>
					</cell>
				</row>
				<row>
					<cell sclass="row-title">Bio :</cell>
					<cell><textbox id="bio" multiline="true" hflex="1" height="200px" /></cell>
				</row>
			</rows>
		</grid>
		<hlayout>
			<button id="saveProfile" label="Save"/>
			<button id="reloadProfile" label="Reload"/>
		</hlayout>
	</vlayout>
</window>

• Line 4: Caption can be used to build compound header with image for a Groupbox and Window.
• Line 5: Vlayout is a light-weight layout component which arranges child components vertically without splitter, align, pack support.
• Line 13: Cell is used inside Row, Hbox, or Vbox for fully controlling style and layout.
• Line 19, 26, 31: Specify constraint attribute of a input component can activate client-side validation feature. Then, the input component will show error message when input value doesn't match specified constraint rule. ''Textbox'' and ''Datebox'' has different syntax of constraint rule.
• Line 49: Hlayout, like Vlayout, but arrange child components horizontally.

Display a Collection of Data

public class ProfileViewController extends SelectorComposer<Component>{
	...
	@Wire
	Listbox country;

	@Override
	public void doAfterCompose(Component comp) throws Exception{
		super.doAfterCompose(comp);
		
		ListModelList<String> countryModel = new ListModelList<String>(CommonInfoService.getCountryList());
		country.setModel(countryModel);
		
		refreshProfileView();
	}

	...
}

Handle Events in a Composer

public class ProfileViewController extends SelectorComposer<Component>{

	//wire components
	@Wire
	Label account;
	@Wire
	Textbox fullName;
	@Wire
	Textbox email;
	@Wire
	Datebox birthday;
	@Wire
	Listbox country;
	@Wire
	Textbox bio;

	@Listen("onClick=#saveProfile")
	public void doSaveProfile(){
		UserCredential cre = authService.getUserCredential();
		User user = userInfoService.findUser(cre.getAccount());
		if(user==null){
			//TODO handle un-authenticated access 
			return;
		}
		
		//apply component value to bean
		user.setFullName(fullName.getValue());
		user.setEmail(email.getValue());
		user.setBirthday(birthday.getValue());
		user.setBio(bio.getValue());
		
		Set<String> selection = ((Selectable)country.getModel()).getSelection();
		if(!selection.isEmpty()){
			user.setCountry(selection.iterator().next());
		}else{
			user.setCountry(null);
		}
		
		userInfoService.updateUser(user);
		
		Clients.showNotification("Your profile is updated");
	}
	...
}

public class ProfileViewController extends SelectorComposer<Component>{


	//wire components
	@Wire
	Label account;
	@Wire
	Textbox fullName;
	@Wire
	Textbox email;
	@Wire
	Datebox birthday;
	@Wire
	Listbox country;
	@Wire
	Textbox bio;

	...
	@Listen("onClick=#reloadProfile")
	public void doReloadProfile(){
		refreshProfileView();
	}

	private void refreshProfileView() {
		UserCredential cre = authService.getUserCredential();
		User user = userInfoService.findUser(cre.getAccount());
		if(user==null){
			//TODO handle un-authenticated access 
			return;
		}
		
		//apply bean value to UI components
		account.setValue(user.getAccount());
		fullName.setValue(user.getFullName());
		email.setValue(user.getEmail());
		birthday.setValue(user.getBirthday());
		bio.setValue(user.getBio());
		
		((Selectable)country.getModel()).addToSelection(user.getCountry());
	}
}