Implementing a UI with JSF Views

Your services and managed beans are all set for action, but how will your users interact with the portlet? You’ll need to implement a user interface for your users to interact with using JSF views.

You’ve briefly read about the views you’ll need to incorporate. When you first created your JSF guestbook portlet, a view.xhtml file was automatically created with some default code. For your guestbook, you’ll edit this file and create the guestbook, entry, and master XHTML files. You’ll learn about each view’s purpose, and then add the appropriate code to get your guestbook up and running.

Each view represents a page in your guestbook. For instance, if you were to click an Add Guestbook button, the rendered page to add a guestbook would be the guestbook view. The same concept applies for the entry view. The master view represents the default page a user views that is not related to creating a new guestbook or entry entity. Lastly, the view communicates with your guestbook bean, and handles the navigation between views.

Now that you have a fundamental understanding of the views and what they do, it’s time to dive in and create them!

Editing the Default View

Currently, your guestbook only has the default view, which has some filler text. The view.xhtml file located in your portlet’s docroot/views directory is going to serve as the default navigation view. This means that every time a button is clicked or a page is rendered, it will be processed through your view.xhtml file. Therefore, this view is very bare bones, and only points to the view that should be rendered.

As was mentioned earlier, there are three additional views, so you’ll use a choose-when conditional statement to select the appropriate view to be rendered. Replace the code between the <f:view>...</f:view> tags with the following:

<h:head />
<h:body>
    <c:choose>
        <c:when test="#{guestbookBacking.editingGuestbook}">
            <ui:include src="/views/guestbook.xhtml" />
        </c:when>
        <c:when test="#{guestbookBacking.editingEntry}">
            <ui:include src="/views/entry.xhtml" />
        </c:when>
        <c:otherwise>
            <ui:include src="/views/master.xhtml" />
        </c:otherwise>
    </c:choose>
</h:body>

If you look back at your GuestbookBacking class, you’ll recall that you had boolean variables editingGuestbook and editingEntry. The view.xhtml calls those variables to check their value. For instance, if the editingGuestbook variable is true, the view.xhtml renders the guestbook view. A similar process is completed for the editingEntry variable and entry view, if the editingGuestbook variable was false. If both are false, the view.xhtml renders the master view.

Awesome! Your default navigation view is complete. It’s almost time to create the views to navigate to, but first, you’ll create your language keys.

Specifying Your Language Keys

Before you begin creating your UI, it’s wise to specify your language keys. By specifying language keys, you can reuse phrases in any of your views. You can also create multiple language properties files, or resource bundles, to offer translations. If you’d like to learn more information about language keys and localization, visit the Localization module, which offers several useful tutorials on this subject.

For the JSF guestbook, you’ll stick to providing language keys for English.

  1. Open the JSF guestbook portlet’s docroot/WEB-INF/src/Language_en_US.properties file and delete any existing language keys.

  2. Add the following language keys:

     add-guestbook=Add Guestbook
     new-entry=New Entry
     new-guestbook=New Guestbook
     no-entries-yet=No entries yet ...
    

    These language keys will be used throughout your views. If you’re wondering if that’s the only place the guestbook can look for language keys, the answer is no. When the portlet is deployed to Liferay Portal, it will have access to Liferay’s default language keys, which are available to all portlets in the portal.

  3. Next, you’ll need to specify custom JSF validation messages. It’s a best practice to provide these in a separate resource bundle. Right-click the docroot/WEB-INF/src directory and select NewFile.

  4. Give the new file the name i18nFaces.properties and click Finish. If your curious, i18n stands for Internationalization, which is used for adapting to multiple languages. As was stated earlier, you’ll focus on English in the learning path, but it’s a best practice to provide this file in JSF portlets.

  5. Add the following JSF-specific validation messages into the i18nFaces.properties file:

     javax.faces.component.UIInput.REQUIRED=Value is required
     javax.faces.converter.DateTimeConverter.DATE=Invalid date format
    
  6. For your portlet to recognize this new properties file as a language resource bundle, you’ll need to specify it in your faces-config.xml file. Open your guestbook portlet’s docroot/WEB-INF/faces-config.xml file and add the following code between the <faces-config>...</faces-config> tags:

     <application>
         <message-bundle>i18nFaces</message-bundle>
     </application>
    

Your guestbook portlet is now equipped with all of its language keys. Now it’s time to begin creating your portlet’s views.

Creating Your Guestbook’s Master View

Now that you have your navigation view and language keys configured, it’s time to create the actual pages your portlet’s users will see.

As was mentioned earlier, when the boolean variables editingGuestbook and editingEntry in your guestbook bean are false, the master view is rendered. When these two variables are false, it means that the user has not yet selected to edit a guestbook or guestbook entry, so the master page should be displayed. Therefore, the master view must offer a way for the user to navigate to your guestbook and entry views. It should also display your created guestbooks and their entries.

The final master view will appear in your guestbook portlet similar to the figure below:

Figure 1: The master view provides the Add Guestbook and Add Entry buttons, allowing a user to navigate to the guestbook and entry views.

Figure 1: The `master` view provides the *Add Guestbook* and *Add Entry* buttons, allowing a user to navigate to the `guestbook` and `entry` views.

Follow the steps below to create the master view for your guestbook portlet.

  1. Right-click on your guestbook’s docroot/views folder and select NewFile. Name the file master.xhtml and click Finish.

    Figure 2: Make sure to specify the full name and extension of the view and click Finish.

    Figure 2: Make sure to specify the full name and extension of the view and click *Finish*.

  2. Add the following XML version and <f:view>...</f:view> tags:

     <?xml version="1.0"?>
    
     <f:view xmlns="http://www.w3.org/1999/xhtml" xmlns:c="http://java.sun.com/jsp/jstl/core"
         xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html" 
         xmlns:ui="http://java.sun.com/jsf/facelets">
    
     </f:view>
    

    The <f:view> tag is the container for all JSF component tags used on your guestbook page. You’ve specified the libraries you’ll use in this container.

  3. Next add the following code within the <f:view>...</f:view> tags, which creates the guestbook tabs:

     <h:form>
         <h:messages globalOnly="true" layout="table" />
         <br />
             <span class="guestbook_tab">
                 <h:outputText value=" " />
             </span>
             <ui:repeat value="#{guestbookBacking.guestbooks}" var="guestbook">
                 <span class="#{(guestbook.guestbookId == guestbookBacking.selectedGuestbook.guestbookId) ? 'guestbook_tab_active' : 'guestbook_tab'}">
                     <h:outputText rendered="#{guestbook.guestbookId == guestbookBacking.selectedGuestbook.guestbookId}" value="#{guestbook.name}" />
                     <h:commandLink action="#{guestbookBacking.select(guestbook)}" immediate="true" rendered="#{guestbook.guestbookId != guestbookBacking.selectedGuestbook.guestbookId}" value="#{guestbook.name}">
                         <f:ajax render="@all" />
                     </h:commandLink>
                 </span>
             </ui:repeat>
             <span class="guestbook_tab">
                 <h:outputText value=" " />
             </span>
         <br />
         <br />
    

    This code snippet creates the guestbook tabs by grabbing the list of guestbooks stored on the view scoped guestbook bean. Then each guestbook is assigned a tab and rendered using its unique guestbookId.

    You’ll also notice another call to the guestbook bean within the <h:commandLink>...</h:commandLink> tags. This is used when a new guestbook has been submitted from the guestbook view, and a new tab for the guestbook must be created. Here, the bean’s select(guestbook) method is called, which sets the new selected guestbook on the guestbook bean for storage, and forces a reload of all the guestbooks stored on the bean. Once the list of guestbooks on the bean are reloaded, all the guestbooks you’ve created can be accurately displayed as guestbook tabs.

    Lastly, notice that the <h:commandLink> tag uses AJAX. If you’re unfamiliar with AJAX, you can read an AJAX general overview here. In summary, it provides asynchronous sending and receiving of data to/from a server. This allows for much quicker response time in your portlet. You can also learn more about the <f:ajax> tag specifically by visiting its VDL docs.

  4. Now you’ll add the buttons that provide access to your guestbook and entry views, which will be created in later sections. Add the following code after the last <br /> tag:

     <h:commandButton action="#{guestbookBacking.add}" styleClass="btn btn-default" value=" #{i18n['add-guestbook']} ">
         <f:ajax render="@all" />
     </h:commandButton>
     <h:commandButton action="#{entryBacking.add}" styleClass="btn btn-default" value=" #{i18n['add-entry']} ">
         <f:ajax render="@all" />
     </h:commandButton>
     <br />		
     <br />
    

    Each button calls the guestbook or entry entity’s bean, which opens a request to add a new entity. The instance of the entity is stored on the guestbook bean, and when the bean is called, it navigates the portlet to the appropriate view to display.

  5. Lastly, add the following choose-when statement after the last <br /> tag, which displays your guestbook entries:

         <c:choose>
             <c:when test="#{empty guestbookBacking.entries}">
                 <h:outputText value="#{i18n['no-entries-yet']}" />
             </c:when>
             <c:otherwise>
                 <h:dataTable styleClass="table table-bordered table-hover table-striped" rowClasses="table-cell "
                     value="#{guestbookBacking.entries}" var="entry">
                     <h:column>
                         <f:facet name="header"><h:outputText value="#{i18n['message']}" /></f:facet>
                         <h:outputText value="#{entry.message}" />
                     </h:column>
                     <h:column>
                         <f:facet name="header"><h:outputText value="#{i18n['name']}" /></f:facet>
                         <h:outputText value="#{entry.name}" />
                     </h:column>
                </h:dataTable>
            </c:otherwise>
        </c:choose>
     </h:form>
    

    When a guestbook has no entries, the no-entries-yet language key that you specified in Language_en_US.properties is displayed. Otherwise, a data table is created displaying inputted entries for the currently selected guestbook.

Your master view is complete! There is one last thing you’ll need to do to make your view stylistically pleasing: styling.

The guestbook portlet should look professional, as many users will be looking at it for various events. Luckily, JSF portlets allow for CSS files, which help style the portlet. You’ll need to add some styling to the guestbook tabs, as they are not very good looking, by default.

When you first created the guestbook portlet, a blank docroot/css/main.css file was created, by default. Add the following code to main.css file to improve your guestbook tabs visually in your UI:

.guestbook_tab,.guestbook_tab_active {
    line-height: 20px;
    padding: 8px 12px 3px 12px;
    }

.guestbook_tab {
    border-bottom: 1px solid #ddd;
}

.guestbook_tab_active {
    border-left: 1px solid #ddd;
    border-top: 1px solid #ddd;
    border-right: 1px solid #ddd;
    border-bottom-left-radius: 0px;
    border-bottom-right-radius: 0px;
    border-top-left-radius: 4px;
    border-top-right-radius: 4px;
    font-weight: bold;
}

That’s it! Your guestbook portlet’s master view is complete. It displays your created guestbooks in interactive tabs, lists your guestbook entries in a data table, and gives you two buttons that navigate you to the guestbook and entry views.

Next, you’ll create the remaining views so you can create new guestbooks and entries.

Creating Your Guestbook View

The guestbook view will serve as the view that is displayed when a user clicks the Add Guestbook button. The final guestbook view will appear in your Guestbook portlet like the figure below:

Figure 3: The guestbook view displays a Name field, a button to save the guestbook, and a button to cancel out of the view.

Figure 3: The `guestbook` view displays a Name field, a button to save the guestbook, and a button to cancel out of the view.

  1. Right-click on your guestbook portlet’s docroot/views folder and select NewFile. Give it the name guestbook.xhtml and click Finish.

  2. Add the following XML version and <f:view> element to your guestbook view:

     <?xml version="1.0"?>
    
     <f:view xmlns="http://www.w3.org/1999/xhtml" xmlns:aui="http://liferay.com/faces/aui"
         xmlns:c="http://java.sun.com/jsp/jstl/core" xmlns:f="http://java.sun.com/jsf/core"
         xmlns:h="http://java.sun.com/jsf/html" xmlns:ui="http://java.sun.com/jsf/facelets">
    
     </f:view>
    

    This <f:view> tag is identical to your master view’s <f:view> tag.

  3. Next, add the following choose-when statement within the <f:view>...</f:view> tags:

     <h:form>
         <c:choose>
             <c:when test="#{empty guestbookBacking.selectedGuestbook.name}">
                 <h3>#{i18n['new-guestbook']}</h3>
             </c:when>
             <c:otherwise>
                 <h3>#{i18n['editing']} #{guestbookBacking.selectedGuestbook.name}</h3>
             </c:otherwise>
         </c:choose>
    

    When there’s no guestbook name stored on your guestbook bean, the new-guestbook language key is displayed on the page. In your portlet, your selected guestbook is always empty when you’ve first arrived to the guestbook view, right after selecting the Add Guestbook button.

    Otherwise, if the selected guestbook has a name, the editing language key displays, which means you’ve already created the selected entry and are now editing it. This scenario is not possible at the moment, but will be developed in a later JSF learning path on creating action buttons.

    You’ll add the necessary fields and buttons in the next step.

  4. Now you’ll need to create the fields and buttons that should be displayed for this view. Add the code snippet right after the </c:choose> tag.

         <aui:fieldset>
             <aui:field id="guestbookNameField" label="#{i18n['name']}">
                 <h:message for="guestbookName" />
                 <h:inputText id="guestbookName" required="true" value="#{guestbookBacking.selectedGuestbook.name}">
                     <f:ajax render="guestbookNameField" />
                 </h:inputText>
             </aui:field>
         </aui:fieldset>
         <h:commandButton action="#{guestbookBacking.save}" styleClass="btn btn-default" value="#{i18n['save']}">
             <f:ajax execute="@form" render="@all" />
         </h:commandButton>
         <h:commandButton action="#{guestbookBacking.cancel}" styleClass="btn btn-default" value="#{i18n['cancel']}">
             <f:ajax render="@all" />
         </h:commandButton>
     </h:form>
    

    First, you used AUI tags to create the guestbook name field. Remember, you’re able to do this because you specified your portlet’s JSF component suite as being Liferay Faces Alloy. Therefore, your portlet has access to the AUI library from the liferay-faces-alloy.jar file, located in your guestbook portlet’s docroot/WEB-INF/lib directory.

    Next, you created two buttons named Save and Cancel. These buttons’ actions are available by calling the guestbook backing bean’s save() and cancel() methods.

    Lastly, notice that the AUI field and both buttons use AJAX. As we discussed earlier, this provides a much quicker response time for these portlet actions because of asynchronous communication with the server.

Terrific! Your guestbook view is complete!

Now it’s time to create the entry view for when a user would like to add a guestbook entry.

Creating Your Guestbook Entry View

Now that you can add guestbooks, it’s time to create the view that allows users to create guestbook entries. The entry view will display when clicking on the Add Entry button.

Figure 4: The entry view displays three text fields, a button to save the entry, and a button to cancel out of the view.

Figure 4: The `entry` view displays three text fields, a button to save the entry, and a button to cancel out of the view.

  1. Right-click on your guestbook portlet’s docroot/views folder and select NewFile. Give it the name entry.xhtml and click Finish.

  2. Add the following XML version and <f:view>...</f:view> tags:

     <?xml version="1.0"?>
    
     <f:view xmlns="http://www.w3.org/1999/xhtml" xmlns:aui="http://liferay.com/faces/aui"
         xmlns:c="http://java.sun.com/jsp/jstl/core" xmlns:f="http://java.sun.com/jsf/core"
         xmlns:h="http://java.sun.com/jsf/html" xmlns:ui="http://java.sun.com/jsf/facelets">
    
     </f:view>
    

    This <f:view> tag is the same as your other views’ <f:view> tags.

  3. Next, add the following choose-when statement within the <f:view>...</f:view> tags:

     <h:form>
         <c:choose>
             <c:when test="#{empty guestbookBacking.selectedEntry.name}">
                 <h3>#{i18n['new-entry']}</h3>
             </c:when>
             <c:otherwise>
                 <h3>#{i18n['editing']} #{guestbookBacking.selectedEntry.name}</h3>
             </c:otherwise>
         </c:choose>
    

    This choose-when statement is very similar to the one used previously in guestbook.xhtml. When the selected entry stored on the guestbook bean is empty, the new-entry language key is displayed on the page. If the selected entry is empty, this means you’ve clicked the Add Entry button and have just arrived at the entry view.

    If the selected entry is not empty, you’ve already created the selected entry and are now editing it. If this is the case, the editing language key is displayed. This is not possible at the moment since you haven’t created a way to edit an entry yet. You’ll create a way to do this when creating action buttons for your Guestbook portlet.

  4. Create your entry view’s text fields by adding the following code right after the </c:choose> tag:

     <aui:fieldset>
         <aui:field id="entryNameField" label="#{i18n['name']}">
             <h:message for="entryName" />
             <h:inputText id="entryName" required="true" value="#{guestbookBacking.selectedEntry.name}">
                 <f:ajax render="entryNameField" />
             </h:inputText>
         </aui:field>
         <aui:field id="entryEmailField" label="#{i18n['email']}">
             <h:message for="entryEmail" />
             <h:inputText id="entryEmail" required="true" validatorMessage="#{i18n['please-enter-a-valid-email-address']}"
                 value="#{guestbookBacking.selectedEntry.email}">
                 <f:validateRegex pattern=".+[@].+[.].+" />
                 <f:ajax render="entryEmailField" />
             </h:inputText>
         </aui:field>
         <aui:field id="entryMessageField" label="#{i18n['message']}">
             <h:message for="entryMessage" />
             <h:inputTextarea id="entryMessage" required="true" value="#{guestbookBacking.selectedEntry.message}">
                 <f:ajax render="entryMessageField" />
             </h:inputTextarea>
         </aui:field>
     </aui:fieldset>
    

    Like the guestbook view, your entry view uses AUI to create its text fields. You’ve created three text fields: Name, Email, and Message.

    A cool feature about the JSF guestbook portlet is how quickly it can validate your inputs. For instance, you’ll notice the following tag for the entryEmail:

     <f:validateRegex pattern=".+[@].+[.].+" />
    

    The inputted email address is validated to ensure that it follows standard email syntax protocol. The use of AJAX quickly checks the inputted email once the user removes the cursor from the entryEmail field. This quick validation prevents incorrect syntax from even reaching your setter methods.

    In turn, when using JSF, you have an extra layer of protection from your database, safeguarding against malicious content, or even syntactically incorrect text like the guestbook’s Email field.

    Figure 5: With the insertion of an angle bracket, rather than a period, the guestbook portlet immediately displays an error message.

    Figure 5: With the insertion of an angle bracket, rather than a period, the guestbook portlet immediately displays an error message.

  5. Create your entry view’s buttons by adding the following code below the </aui:fieldset> tag:

         <h:commandButton action="#{entryBacking.save}" styleClass="btn btn-default" value="#{i18n['save']}">
             <f:ajax execute="@form" render="@all" />
         </h:commandButton>
         <h:commandButton action="#{entryBacking.cancel}" immediate="true" styleClass="btn btn-default" value="#{i18n['cancel']}">
             <f:ajax render="@all" />
         </h:commandButton>
     </h:form>
    

    These buttons are almost identical to your guestbook view’s Save and Cancel button. The only differences are, of course, you’re calling the save() and cancel() methods from the EntryBacking bean.

Your entry view is now complete!

Re-deploy the Guestbook portlet and test out your new portlet by adding guestbooks and guestbook entries. You now have a fully functional JSF guestbook, which can be used to add guestbooks and guestbook entries. However, what if you want to restrict access to adding or viewing certain entries? You can learn how to implement permissions for your JSF guestbook portlet in the next learning path.

« Creating Managed Beans to Use ServicesSetting Permissions Using JSF »
这篇文章有帮助吗?
1 人中有 1 人觉得有帮助