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This chapter is from the book

This chapter is from the book

2.3 Sample Application

Now that you're comfortable with Creator, let's create a simple web application. Even though this application is simplistic, it hints at some of the power in Creator. Figure 2-22 on page 46 provides a preview of this web application.

02fig24.gifFigure 2-22 Web application Echo running in a browser

Create a Project

Close project Login1 if it's open.

  1. From the Welcome window, select button Create New Project.

  2. Specify Echo for the Name, then click OK.

Specify Title

Creator initializes a project for you and brings up the design canvas editor. Now you'll be able to add components and modify properties.

  1. If the Properties window is not enabled for the page, select the page by clicking anywhere inside the design canvas.

  2. In the Properties window under General, change the Title attribute to Echo. Finish with <Enter>.

Add Components

You'll add three components to the page: a component label, a text field, and an output text component. When you created project Echo and Creator brought up the design canvas, this made the JSF Standard Components palette visible.

  1. From the JSF Standard Components palette, select Component Label and drag it over to the design canvas. Drop it onto the canvas, near the top on the left side. Don't resize it.

    If you resize the component, Creator generates static length and width attributes for your component. If you leave it unsized, the rendering mechanism will dynamically size the component to accommodate the text it needs to display.

  2. Component label is a composite component; it contains an embedded (nested) output text component. The output text component displays the label. From the Application Outline view, select the component label's nested output text component, named componentLabel1Text.

    Creator provides an enhanced selection mechanism for composite components (such as component label). In the design canvas, select the component label and look in the Properties window to see which component is selected. Now click the component again and you'll see a different component's properties. For component label, you switch back and forth between the top-level, label component and the embedded output text component by clicking the component in the design canvas.

  3. Now go to the Properties window and select the value attribute. Type the label Type in some text. Finish with <Enter>. The text you type will appear in the component.

  4. From the JSF Standard Components palette, select component Text Field and place it on the design canvas underneath the component label you just added.

  5. Make sure that it's selected, and in the Properties window, change its value attribute to Echo Text. Finish with <Enter>.

  6. Still in the Properties window for the text field, change its title attribute to The text you enter here will be echoed below. Finish with <Enter>. You've just created a tooltip for this component.

  7. Now select component label componentLabel1 (the top-level component) from the Application Outline view.

  8. In the Properties window, select the small editing square opposite the for attribute. Creator pops up a dialog for you to choose a component id. Select component textField1 and click OK. This associates the label component with the text field component. You'll see (when you run the web application) that this affects GUI operations such as cursor movement and selection behavior. For example, selecting the label also selects the text field.

  9. From the JSF Standard Components palette, select an Output Text component and place it under the text field. (Again, don't resize it.)

You've finished adding the components. Now you will use property binding to bind the text field component value property to the output text component value property. Here's how.

  1. Select the output text component (outputText1), right-click, and choose Property Bindings from the context menu. Creator brings up the Property Bindings dialog. (See Figure 2-21.)

    02fig23.gifFigure 2-21 Property Bindings dialog

  2. Under Select bindable property, choose value Object.

  3. Under Select binding target, expand Page1 > html > body > form1 by clicking the '+' at each level.

  4. Select component textField1 (the text field component you added). Expand the component by clicking '+' on textField1 and select value String. (The properties are listed in alphabetical order, so value is near the end.)

  5. Click the Apply button. (If you don't click the Apply button, Creator doesn't set the property binding.) Under Current binding for value property, you should see the following JSF EL expression

    #{Page1.textField1.value}
    
  6. Click Close to finish.

So, what did all this accomplish? You've just configured property binding on the output text component (id outputText1). This means that JSF gets the value attribute (the text that is displayed on the page) for outputText1 from the text field's value (component textField1). This, in turn, means that whatever you type for input will be echoed in the output text's display.

Deploy and Run

You've finished creating the application. Now it's time to build, deploy, and run it. From the menu bar, select Build > Run Project. Creator builds the application, deploys it, and brings up a browser with the Echo web application running.

Figure 2-22 shows what the browser window displays after you type Hello, World Wide Web inside the text field followed by <Enter>.

Modify Project Echo

As promised, let's access the Clips palette and add some Java code to our project. First, we'll add an output text component.

  1. Make sure the Creator design canvas is visible.

  2. From the JSF Standard Components palette, select Output Text component and place it underneath component outputText1. This adds component outputText2 to your page. (You should see outputText2 when you look at the Application Outline view of the project.)

  3. Make sure component outputText2 is selected and in the Properties window click on the small editing box opposite attribute value.

  4. Creator pops up a dialog to manipulate the component's value. Click button Reset to default. This removes any text from the design canvas for this component.

Now you will bring up the Java source editor to manipulate the Java page bean for this page.

  1. Place the cursor anywhere in the design grid, right-click, and select View Page1 Java Class. This brings up the Java Source editor with file Page1.java.

  2. Open the dropdown menu at the top of the editor pane and select the constructor, Page1(). Creator will place the cursor at the beginning of this method and highlight the line in yellow. (Note that some Creator-managed code is hidden—"folded"—to help keep your editor window uncluttered.)

  3. Move the cursor to the end of the following line.

    // Additional user provided initialization code
                
  4. Click the mouse and start a new line by pressing <Enter>. Since you're in the Java Source editor, the Clips palette is visible to the left of the editor pane.

  5. Select Java Basics > Concatenate Strings. Drag this clip to your Java source and drop it directly underneath the above comment line (where you just added a new line).

Creator adds the following code to your Java source file.

// Concatenating Strings
   // This clip shows how to concatenate two strings in Java
   // and places the result in a text field component
   
   //TODO: set string1 and string2
   String string1 = "concat";
   String string2 = "enate";
   String resultString = string1 + string2;
   
   // show the result in a component on the page
   getInputText1().setValue(resultString);
   

Note that the last line is underlined (in red), since it produces a syntax error. Before we fix the error, let's align the newly added code.

  1. Select the code you just added by swiping all the lines with the mouse. The selected lines turn gray.

  2. At the top of the editor pane, hold the cursor over the icons until you find the icon with the tooltip "Shift Line Right (Ctrl + T)."

  3. Click the Shift Right icon until the selected code block is aligned with the line above it.

Let's fix the flagged error now. We need to use method getOutputText2() instead of method getInputText1().

  1. Change the underlined line above to the following.

    getOutputText2().setValue(resultString);
    

    (Remove InputText1() and start typing the replacement text. Then press <Ctrl-Space> and see the code completion box, as shown in Figure 2-23. Here we are given two choices. Use the down-arrow key to select method getOutputText2() and press <Enter>.)

    02fig25.gifFigure 2-23 Code completion helping out

  2. Redeploy and run web application Echo. You'll see that the String "concatenate" displays in the output text component on the page. We placed this code in Page1's constructor. This is where you provide initialization code that is executed before the page is displayed.

This completes our tour of Creator. The next chapter provides a detailed description of the JSF standard components, validators, and converters.

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