Small Talks/2013/June/Column Chooser

Author
Sam Chuang, Engineer, Potix Corporation

Date
June 18, 2013

Version
ZK 6.5 and later

Introduction

By default, in a ZK Grid or Listbox, you can click the arrow on the header menu to select the columns to hide or to display. When there are a lot of columns, a Columnchooser can be very convenient for arranging these columns. Columnchooser is a popup component that shows a dialog of columns, grouped by column visibility.

Columnchooser's dialog box is done easily by putting up two listboxes and a few buttons:

• Left Listbox: hidden columns that support drag and drop
• Right Listbox: visible columns that support drag and drop
• Add button: change selected hidden column to visible
• Remove button: change selected visible column to hidden
• Move Up button: move selected visible column up
• Move Down button: move selected visible column down
• OK button: confirm changes
• Cancel button: cancel changes

Columnchooser is designed to work with any tabular components, which means you can easily integrate it with Grid and Listbox. Another important feature of Columnchooser is that it's based on ZK MVVM which means that the UI (dialog) it can be easily customizable without touching ViewModel's code.

How it Works

Button

OK

The OK button is used for confirming modified changes. If user doesn't click OK, the modification will be lost and reverted back to previous state.

Demonstration:

• Original view

• After modification, OK to confirm.

• Result

Cancel

Cancel is used to revert to previous state.

Demonstration:

• Original view

• After modification, click Cancel button to revert and not save your changes

• Result

Add to Visible Column

Add button is used to move a hidden column to become a visible column

Demonstration:

• Original view

• Select a column, then click Add

• Click OK to confirm

• Result

Remove Visible Column

Remove button is used to move a visible column to become a hidden column

Demonstration:

• Original view

• Select a visible column, then click Remove

• Click OK to confirm

• Result

Move Visible Column Up

Move Up button is used to change column order, move selected column upwards.

Demonstration:

• Original view

• Select a visible column, then click Move Up'

• Click OK to confirm

• Result

Move Visible Column Down

Move Down button is used to change column order, move selected column down.

Demonstration:

• Original view

• Select a visible column, then click Move Down

• Click OK to confirm

• Result

Drag & Drop

Drag Hidden Column to Visible Column

Demonstration:

• Original view

• Drag the hidden column and drop it to the visible column area

• Click OK to confirm

• Result

Drag Visible Column to Hidden Column

Demonstration:

• Original view

• Drag a visible column and drop it to the hidden column area

• Click OK to confirm

• Result

Drag Column and Drop on Any Column

Demonstration:

• Original view

• Drag visible column and drop it to the Birth column

• Click OK to confirm

• Result

Usage

Specify Visible Columns and Hidden Columns

Invoke Columnchooser.setVisibleColumns(List<String> columns) and Columnchooser.setHiddenColumns(List<String> columns) to setup the columns.

ZUL

<columnchooser 
	visibleColumns="@load(vm.visibleColumnLabels)"
	hiddenColumns="@load(vm.hiddenColumnLabels)" />

Java

public ArrayList<String> getVisibleColumnLabels() {
	...
}
	
public ArrayList<String> getHiddenColumnLabels() {
	...
}

Open Dialog

Columnchooser' is a popup component, invoke Columnchooser.open(Component ref, String position) to open a dialog.

Event

When user makes a change and confirms the change, Columnchooser will fire a ColumnVisibilityChangeEvent event named onColumnVisibilityChange

ZUL

<columnchooser 
	visibleColumns="@load(vm.visibleColumnLabels)"
	hiddenColumns="@load(vm.hiddenColumnLabels)"
	onColumnVisibilityChange="@command('doColumnVisibilityChange', 
		visibleColumns=event.visibleColumns, 
		hiddenColumns=event.hiddenColumns)"></columnchooser>

Java

@Command
public void doColumnVisibilityChange(
		@BindingParam("visibleColumns") List<String> visibleColumns, 
		@BindingParam("hiddenColumns") List<String> hiddenColumns) { 
...
}

Template

Default

The Columnchooser contains a default implementation: columnchooser.zul

<zk xmlns:n="native">
	<vlayout 
		apply="org.zkoss.bind.BindComposer" 
		viewModel="@id('vm') @init('org.zkoss.addon.columnchooser.impl.ColumnchooserViewModel')">
		<n:span>Choose the fields to display.</n:span>
		<hlayout>
			<vlayout>
				Available fields:
				<listbox model="@load(vm.hiddenColumns)" width="150px"
					height="200px" droppable="true" selectedItem="@bind(vm.selectedHiddenColumn)"
					onDrop="@command('dropToHiddenColumns', column=event.dragged.value)">
					...
				</listbox>
			</vlayout>
				...
			<vlayout>
				Displayed Columns:
				<listbox model="@load(vm.visibleColumns)" width="150px"
					height="200px" droppable="true" selectedItem="@bind(vm.selectedVisibleColumn)"
					onDrop="@command('dropToVisibleColumns', column=event.dragged.value)">
					...
				</listbox>
			</vlayout>
		</hlayout>
		<hbox pack="end" width="100%" spacing="5px">
			<button onClick="@command('ok')" label="OK" mold="trendy" width="75px"></button>
			<button onClick="@command('cancel')" label="Cancel" mold="trendy" width="75px"></button>
		</hbox>
	</vlayout>
</zk>

The default implementation groups columns by column visibility into two listboxes.

Custom Template

Config template per instance

As the component is based on MVVM, developer can easily change the view by Columnchooser.setTemplate(String uri)

ZUL

<columnchooser template="/customColumnChooser.zul"
	visibleColumns="@load(vm.visibleColumnLabels)" 
	hiddenColumns="@load(vm.hiddenColumnLabels)"
	onColumnVisibilityChange="@command('doColumnVisibilityChange', 
		visibleColumns=event.visibleColumns, 
		hiddenColumns=event.hiddenColumns)"></columnchooser>

customColumnChooser.zul

<zk xmlns:n="native">
	<window apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('org.zkoss.addon.columnchooser.impl.ColumnchooserViewModel')"
		title="Edit Columns" border="normal" mode="highlighted" position="center">
		<vlayout spacing="5px">
			<label>Choose the fields to display.</label>
			<hlayout spacing="10px">
				<vlayout>
					Available fields:
					<listbox model="@load(vm.hiddenColumns)" width="150px"
						height="200px" droppable="true" selectedItem="@bind(vm.selectedHiddenColumn)"
						onDrop="@command('dropToHiddenColumns', column=event.dragged.value)">
						...
					</listbox>
				</vlayout>
					...
				<vlayout>
					Displayed Columns:
					<listbox model="@load(vm.visibleColumns)" width="150px"
						height="200px" droppable="true" selectedItem="@bind(vm.selectedVisibleColumn)"
						onDrop="@command('dropToVisibleColumns', column=event.dragged.value)">
						...
					</listbox>
				</vlayout>
			</hlayout>
			<hbox pack="end" width="100%" spacing="5px">
				<button onClick="@command('ok')" label="OK" mold="trendy" width="75px"></button>
				<button onClick="@command('cancel')" label="Cancel" mold="trendy" width="75px"></button>
			</hbox>
		</vlayout>
	</window>
</zk>

Config template globally

Change the template view globally by using library property org.zkoss.addon.columnchooser.template in zk.xml

	<library-property>
	    <name>org.zkoss.addon.columnchooser.template</name>
	    <value>/customColumnChooser.zul</value>
	</library-property>

View Model

The default template contains a default ColumnchooserViewModel that implements from Columnchooser.ViewModel

Develper can use customized ViewModel base on ColumnchooserViewModel

Use Columnchooser in Grid and Listbox

Columnchooser supports both MVC and MVVM and can be easily integrated into Grid and Listbox. In this section I will provide two simple examples to demonstrate how you can use Columnchooser with Grid in the MVVM way, and how you can use Columnchooser with Listbox in the MVC way.

Grid with Columnchooser Demo (MVVM)

index.zul

<zk>
	<window apply="org.zkoss.bind.BindComposer" border="normal"
		viewModel="@id('vm') @init('demo.ProfileViewModel')" hflex="1" vflex="1">
		<caption label="Column Chooser">
			<!-- default column chooser -->
			<columnchooser id="columnchooser" 
				visibleColumns="@load(vm.visibleColumnLabels)"
				hiddenColumns="@load(vm.hiddenColumnLabels)"
				onColumnVisibilityChange="@command('doColumnVisibilityChange', 
					visibleColumns=event.visibleColumns, 
					hiddenColumns=event.hiddenColumns)"></columnchooser>
			<combobutton label="Column Chooser"
				onClick="@command('openDefaultColumnChooser', ref=self)">
				<!-- custom column chooser -->
				<columnchooser 
					template="/customColumnChooser.zul"
					visibleColumns="@load(vm.visibleColumnLabels)" 
					hiddenColumns="@load(vm.hiddenColumnLabels)"
					onColumnVisibilityChange="@command('doColumnVisibilityChange', 
						visibleColumns=event.visibleColumns, 
						hiddenColumns=event.hiddenColumns)"></columnchooser>
			</combobutton>
		</caption>
		<grid model="@load(vm.profiles)" height="500px">
			<columns children="@load(vm.visibleColumns)">
				<template name="children" var="columnInfo">
					<column label="@load(columnInfo.label)"></column>
				</template>
			</columns>
			<template name="model" var="profile">
				<row children="@init(vm.visibleColumns) @template(each.templateName)">
					<template name="label" var="columnInfo">
						<label value="@load(profile[columnInfo.value])"></label>
					</template>
					<template name="birth" var="columnInfo">
						<datebox value="@load(profile[columnInfo.value])"
							onChange="@command('setBirth', profile=profile, birth=event.target.value)"></datebox>
					</template>
					<template name="married" var="columnInfo">
						<checkbox checked="@load(profile[columnInfo.value])"
							onCheck="@command('setMarried', profile=profile, married=event.checked)"
							label="Married"></checkbox>
					</template>
					<template name="skills" var="columnInfo">
						<chosenbox model="@load(vm.allSkills)"
							onSelect="@command('setSkills', profile=profile, skills=event.selectedObjects)"
							selectedObjects="@load(profile[columnInfo.value])" hflex="true">
							<template name="model" var="item">
								<label value="@load(item)"></label>
							</template>
						</chosenbox>
					</template>
				</row>
			</template>
		</grid>
	</window>
</zk>

• Line 7, 8: setup columns
• Line 16: customize columnchooser dialog
• Line 25 ~ 27: grid headers
• Line 30, 31, 32, 35, 39, 44: row content

ProfileViewModel.java

public class ProfileViewModel {
	...
	@Wire
	Columnchooser columnchooser;
	
	@Init
	public void init() {
		_columns = new ArrayList<ColumnInfo>();
		_columns.add(new ColumnInfo("name", "Name", true, "label"));
		_columns.add(new ColumnInfo("birth", "Birth", true, "birth"));
		_columns.add(new ColumnInfo("married", "Marital status", false, "married"));
		_columns.add(new ColumnInfo("skills", "Professional Skill", false, "skills"));
		
		_data = provideData();
	}
	
	@AfterCompose
	public void afterCompose(@ContextParam(ContextType.VIEW) Component view) {
		Selectors.wireComponents(view, this, false);
	}
	
	@Command
	public void openDefaultColumnChooser(@BindingParam("ref") Component ref) {
		columnchooser.open(ref, "after_end");
	}
	
	public List<Profile> getProfiles() {
		return _data;
	}
	
	public ArrayList<ColumnInfo> getVisibleColumns() {
		return getColumns(Filter.VISIBLE);
	}
	
	public ArrayList<String> getVisibleColumnLabels() {
		return transform(getVisibleColumns(), Transformer.TO_LABEL);
	}
	
	public ArrayList<ColumnInfo> getHiddenColumns() {
		return getColumns(Filter.HIDDEN);
	}
	
	public ArrayList<String> getHiddenColumnLabels() {
		return transform(getHiddenColumns(), Transformer.TO_LABEL);
	}
	
	@Command
	@NotifyChange({"visibleColumns", "hiddenColumnLabels", 
		"profiles", "visibleColumnLabels", "hiddenColumnLabels"})
	public void doColumnVisibilityChange(@BindingParam("visibleColumns") List<String> visibleColumns, 
		@BindingParam("hiddenColumns") List<String> hiddenColumns) {
		...
	}
	...
}

• Line 9 ~12: all columns of the grid
• Line 24: open columnchooser dialog
• Line 35, 43: column labels
• Line 50: columnchooser onColumnVisibilityChange event

Listbox with Columnchooser Demo (MVC)

columnchooser-mvc.zul

<zk>
<window title="Columnchooser with MVC" border="normal" apply="demo.ProfileCtrl">
	<button id="button" label="Column Chooser"></button>
	<columnchooser id="columnchooser"></columnchooser>
	<listbox id="listbox">
		<listhead id="listhead">
		</listhead>
	</listbox>
</window>
</zk>

ProfileCtrl.java

public class ProfileCtrl extends SelectorComposer<Component> {
	
	@Wire
	Button button;
	
	@Wire
	Columnchooser columnchooser;
	
	@Wire
	Listbox listbox;
	
	List<Profile> profiles = Profiles.provideData();
	
	List<String> visibleColumns;
	
	List<String> hiddenColumns;
	@Override
	public void doAfterCompose(Component comp) throws Exception {
		super.doAfterCompose(comp);
		...
		columnchooser.setVisibleColumns(visibleColumns);
		columnchooser.setHiddenColumns(hiddenColumns);
		...
	}

	@Listen("onClick=#button")
	public void openColumnChooser() {
		columnchooser.open(button, "end_before");
	}
	
	@Listen("onColumnVisibilityChange=#columnchooser")
	public void doColumnVisibilityChange(ColumnVisibilityChangeEvent event) {
		visibleColumns = event.getVisibleColumns();
		hiddenColumns = event.getHiddenColumns();
		
		Listhead listhead = listbox.getListhead();
		listhead.getChildren().clear();
		for (String visibleColumn : visibleColumns) {
			listhead.appendChild(new Listheader(visibleColumn));
		}
		
		listbox.setModel(new ListModelList<Profile>(profiles));
	}
}

• Line 21, 22: setup visible columns and hidden columns
• Line 28: open columnchooser dialog
• Line 31 ~ 34: reset columns
• Line 36 ~ 40: redraw listbox headers
• Line 42: redraw listbox

Summary

In this smalltalk I have demonstrated how developers can easily create a Columnchooser component by putting up basic ZK components and how they can easily integrate this component with Grid, Listbox and any other tabular components.

Columnchooser is implemented in the MVVM way allowing application developers to customize the View extremely easily without changing the ViewModel. On the other hand it supports both MVC and MVVM so you can apply it in whatever pattern you prefer for your application.

Download

You can get the complete source of the example used in this smalltalk from its github or download the Columnchooser binary file here

Comments

Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.