Difference between revisions of "Template:Tutorial common chapters"

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* search cars according to keyword in  model and make.
 
* search cars according to keyword in  model and make.
 
* @param keyword for search
 
* @param keyword for search
* @return list of car that match the keyword
+
* @return list of car that matches the keyword
 
*/
 
*/
 
public List<Car> search(String keyword);
 
public List<Car> search(String keyword);
Line 53: Line 53:
 
</source>
 
</source>
  
In this example, we have defined a class - <tt>CarServeImpl</tt> that implements the above interface. For simplicity, it uses a static list object as the data model. You can rewrite it so that it connects to a database in a real application. Implementation details are not in the scope of this article, please refer to source code repository.
+
In this example, we have defined a class, <code>CarServeImpl</code>, that implements the above interface. For simplicity, it uses a static list object as the data model. You can rewrite it so that it connects to a database in a real application. Its implementation details are not in the scope of this article, please refer to source code repository.
  
 
=Building User Interface =
 
=Building User Interface =
Line 61: Line 61:
 
In ZK, you can use [[ZUML Reference|ZK User Interface Markup Language (ZUML)]], an XML-formatted language, to describe UI. By ZK's convention, the files to describe the user interface with ZUML uses '''.zul''' as the name suffix. In zul files, one component is represented as an XML element (tag) and you can configure each component's style, behavior, and function by setting XML element's attributes. (check [[ZK Component Reference|ZK Component Reference]] for details)  
 
In ZK, you can use [[ZUML Reference|ZK User Interface Markup Language (ZUML)]], an XML-formatted language, to describe UI. By ZK's convention, the files to describe the user interface with ZUML uses '''.zul''' as the name suffix. In zul files, one component is represented as an XML element (tag) and you can configure each component's style, behavior, and function by setting XML element's attributes. (check [[ZK Component Reference|ZK Component Reference]] for details)  
  
In the case of this example application, first of all, we want to design a ''window'' with the specified title and normal border as our application's frame.
+
In this example application, first of all, we want to use a <code>Window</code> with the specified title and normal border as our application's frame.
  
 +
 +
As <code>Window</code> is the outermost component, it is called the ''root component''. <code>Window</code> is a commonly used container because it makes your web application look like a desktop application. Besides, it can also enclose other components. All other components inside <code>Window</code> are called its ''child components'' and should be put in <code><window></code>'s body.
  
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
<source lang="xml">
+
<syntaxhighlight lang="XML" line>
 
+
<window title="Search" border="normal" width="600px">
<window title="Search" width="600px" border="normal">
 
 
<!-- put child components inside a tag's body -->
 
<!-- put child components inside a tag's body -->
 
</window>
 
</window>
</source>
+
</syntaxhighlight>
  
As ''window'' is the outermost component, it is called the ''root component''. ''Window'' is a commonly used container because it is a basic display element of a desktop-like application while it can also enclose other components. All other components inside ''window'' are called its ''child components'' and should be put in window tag's body. We set ''window'''s title bar text with "title" attribute and make ''window'' display a normal border with "border" attribute. For "width" attribute, use CSS like syntax such as "800px" or "60%".
+
* Line 1: Specifying title bar text with <code>title</code> and make <code><window></code> display a normal border with <code>border</code> . For <code>width</code> attribute, use CSS like syntax such as <code>800px</code> or <code>60%</code>.
  
  
Basically, our example application's user interface is divided into 3 areas within the ''window'' (from top to bottom):
+
Our example application's user interface is divided into 3 areas within the <code><window></code> (from top to bottom):
  
 
# search function
 
# search function
Line 89: Line 90:
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
 
<syntaxhighlight lang="XML" line>
 
<syntaxhighlight lang="XML" line>
<div>
+
Keyword:
Keyword:
+
<textbox id="keywordBox" />
<textbox id="keywordBox" />
+
<button id="searchButton" label="Search" iconSclass="z-icon-search" style="margin: 0 0 5px 5px"/>
<button id="searchButton" label="Search" image="/img/search.png" />
 
</div>
 
 
</syntaxhighlight>
 
</syntaxhighlight>
  
* Line 3~4: Specifying the <code>id</code> attribute for some components allows you to control them by referencing their ''id''.  
+
* Line 1~2: Specifying the <code>id</code> attribute for some components allows you to control them by referencing their ''id''.  
* Line 4: You can easily create an image button by specifying the path for the <code>image</code> attribute.  
+
* Line 3: You can use built-in Font Awesome icon at <code>iconSclass</code>. Please refer to [[ZK_Component_Reference/Base_Components/LabelImageElement#IconSclass| LabelImageElement#IconSclass]] for details.
 
 
  
 
== Car List Area ==
 
== Car List Area ==
ZK provides several components to display a collection of data such as ''listbox'', ''grid'', and ''tree''. In this example, we have chosen to use a ''listbox'' to display a list of cars with 3 columns: Model, Make, and Price. We set the "height" attribute, so the number of rows visible is limited with respect to the height specified; you can drag scroll-bar to see the rest of rows. The "emptyMessage" attribute is used to show a message when ''listbox'' contains no items. The ''listbox'' is a container component, and you can add ''listhead'' to define a column. The ''listitem'' is used to display data, and the number of ''listcell'' in one ''listitem'' should equal to the number of ''listheader''. Here we use ''listcell'' with static label to demonstrate structure of a ''listitem'', and we'll talk about how to create ''listitem'' dynamically with respect to each data object in the next chapter.
+
ZK provides several components to display a collection of data such as <code>listbox</code>, <code>grid</code>, and <code>tree</code>. In this example, we use a <code>listbox</code> to display a list of cars with 3 columns: Model, Make, and Price. Here we use <code>listcell</code> with static label to demonstrate structure of a <code>listitem</code>. Later, we'll talk about how to create <code>listitem</code> dynamically with a collection of data.
  
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
<source lang="xml">
+
<syntaxhighlight lang="XML" line>
<listbox id="carListbox" height="160px" emptyMessage="No car found in the result">
+
<listbox id="carListbox" emptyMessage="No car found in the result" rows="5">
<listhead>
+
    <listhead>
<listheader label="Model" />
+
        <listheader label="Model" />
<listheader label="Make" />
+
        <listheader label="Make" />
<listheader label="Price" width="20%"/>
+
        <listheader label="Price" width="20%"/>
</listhead>
+
    </listhead>
<listitem>
+
    <listitem>
<listcell label="car model"></listcell>
+
        <listcell label="car model"></listcell>
<listcell label="make"></listcell>
+
        <listcell label="make"></listcell>
<listcell>$<label value="price" /></listcell>
+
        <listcell>$<label value="price" /></listcell>
</listitem>
+
    </listitem>
</listbox>
+
</listbox>
</source>
+
</syntaxhighlight>
 
+
* Line 1: <code>rows</code> determines the max visible row. <code>emptyMessage</code> is used to show a message when <code>listbox</code> contains no items.
 +
* Line 2: The <code>listbox</code>  is a container component, and you can add <code>listhead</code> to define a column.
 +
* Line 7: The <code>listitem</code> is used to display data, and the number of <code>listcell</code> in one <code>listitem</code> usually equals to the number of <code>listheader</code>.
  
 
== Car Details Area ==
 
== Car Details Area ==
Like the ''hbox'', ''hlayout'' and ''vlayout'' are also layout components which arrange their child components in horizontal and vertical order. But they are more light-weighted than <tt><hbox/></tt>/ <tt><vbox/></tt> since they render <tt>&lt;div/></tt> instead of <tt>>&lt;table/></tt>.  If you don't have alignment need, using <tt><hlayout/></tt>/ <tt><vlayout/></tt> can reduce a page's complexity and your browser's rendering cost.
+
<code>hlayout</code> and <code>vlayout</code> are layout components which arrange their child components in horizontal and vertical order.  
 
 
By combing these 2 layout components, we can display more information on 2 different divisions.  The <tt>style</tt> attribute allows you to customize component's style with CSS syntax.
 
  
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
 
'''Extracted from [https://github.com/zkoss-demo/gettingStarted/blob/master/src/main/webapp/search.zul search.zul]'''
<source lang="xml">
+
<syntaxhighlight lang="XML" line>
 
<hlayout style="margin-top:20px" width="100%">
 
<hlayout style="margin-top:20px" width="100%">
 
<image id="previewImage" width="250px" />
 
<image id="previewImage" width="250px" />
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</vlayout>
 
</vlayout>
 
</hlayout>
 
</hlayout>
</source>
+
</syntaxhighlight>
 
+
* Line 1: the <code>style</code> attribute allows you to customize component's style with CSS syntax.
 
 
You can see the complete zul file through the link in the source repository.
 

Latest revision as of 06:16, 22 December 2023

Tutorial Objective

Our target application is a simple car catalog application. This application has two functions:

  1. Search cars.
    Enter a keyword in the input field, click Search and search results will be displayed in the car list below.
  2. View details.
    Click an item from the car list, the area below the car list will show the selected car's details including model, price, description, and preview.


Tutorial-searchexample.png


Start from Example Project

You can get the source code of this article and import it to your IDE without starting from scratch. Please follow the README to run the project.

If you want to start a new project, please refer to ZK Installation Guide/Quick Start.

Declaring Domain Class

The following is the domain object that represents a car.

public class Car {
	private Integer id;
	private String model;
	private String make;
	private String preview;
	private String description;
	private Integer price;
	//omit getter and setter for brevity
}

We then define a service class to perform the business logic (search cars) shown below:

public interface CarService {

	/**
	 * Retrieve all cars in the catalog.
	 * @return all cars
	 */
	public List<Car> findAll();
	
	/**
	 * search cars according to keyword in  model and make.
	 * @param keyword for search
	 * @return list of car that matches the keyword
	 */
	public List<Car> search(String keyword);
}

In this example, we have defined a class, CarServeImpl, that implements the above interface. For simplicity, it uses a static list object as the data model. You can rewrite it so that it connects to a database in a real application. Its implementation details are not in the scope of this article, please refer to source code repository.

Building User Interface

UI is a good start to building an application as it helps you define the scope of your application. ZK provides hundreds of readily made UI components, so developers can rapidly build their desired user interface by combining and mix-matching these components without having to create a page from scratch.

In ZK, you can use ZK User Interface Markup Language (ZUML), an XML-formatted language, to describe UI. By ZK's convention, the files to describe the user interface with ZUML uses .zul as the name suffix. In zul files, one component is represented as an XML element (tag) and you can configure each component's style, behavior, and function by setting XML element's attributes. (check ZK Component Reference for details)

In this example application, first of all, we want to use a Window with the specified title and normal border as our application's frame.


As Window is the outermost component, it is called the root component. Window is a commonly used container because it makes your web application look like a desktop application. Besides, it can also enclose other components. All other components inside Window are called its child components and should be put in <window>'s body.

Extracted from search.zul

1 	<window title="Search" border="normal" width="600px">
2 		<!-- put child components inside a tag's body -->
3 	</window>
  • Line 1: Specifying title bar text with title and make <window> display a normal border with border . For width attribute, use CSS like syntax such as 800px or 60%.


Our example application's user interface is divided into 3 areas within the <window> (from top to bottom):

  1. search function
  2. car list
  3. car details.
Tutorial-ui-3areas.png


Search Area

ZK components are like building blocks, you can combine and mix-match existing components to construct your desired UI. To allow users to search, we need a text to prompt users for input, a place to enter keywords, and a button for triggering the search. We can use the following ZK components to fulfill this requirement:

Extracted from search.zul

1 Keyword:
2 <textbox id="keywordBox" />
3 <button id="searchButton" label="Search" iconSclass="z-icon-search" style="margin: 0 0 5px 5px"/>
  • Line 1~2: Specifying the id attribute for some components allows you to control them by referencing their id.
  • Line 3: You can use built-in Font Awesome icon at iconSclass. Please refer to LabelImageElement#IconSclass for details.

Car List Area

ZK provides several components to display a collection of data such as listbox, grid, and tree. In this example, we use a listbox to display a list of cars with 3 columns: Model, Make, and Price. Here we use listcell with static label to demonstrate structure of a listitem. Later, we'll talk about how to create listitem dynamically with a collection of data.

Extracted from search.zul

 1 <listbox id="carListbox" emptyMessage="No car found in the result" rows="5">
 2     <listhead>
 3         <listheader label="Model" />
 4         <listheader label="Make" />
 5         <listheader label="Price" width="20%"/>
 6     </listhead>
 7     <listitem>
 8         <listcell label="car model"></listcell>
 9         <listcell label="make"></listcell>
10         <listcell>$<label value="price" /></listcell>
11     </listitem>
12 </listbox>
  • Line 1: rows determines the max visible row. emptyMessage is used to show a message when listbox contains no items.
  • Line 2: The listbox is a container component, and you can add listhead to define a column.
  • Line 7: The listitem is used to display data, and the number of listcell in one listitem usually equals to the number of listheader.

Car Details Area

hlayout and vlayout are layout components which arrange their child components in horizontal and vertical order.

Extracted from search.zul

1 	<hlayout style="margin-top:20px" width="100%">
2 		<image id="previewImage" width="250px" />
3 		<vlayout hflex="1">
4 			<label id="modelLabel" />
5 			<label id="makeLabel" />
6 			<label id="priceLabel" />
7 			<label id="descriptionLabel" />
8 		</vlayout>
9 	</hlayout>
  • Line 1: the style attribute allows you to customize component's style with CSS syntax.