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= NetBeans Project Sample Module Tutorial
:jbake-type: platform_tutorial
:jbake-tags: tutorials 
:jbake-status: published
:syntax: true
:source-highlighter: pygments
:toc: left
:toc-title:
:icons: font
:experimental:
:description: NetBeans Project Sample Module Tutorial - Apache NetBeans
:keywords: Apache NetBeans Platform, Platform Tutorials, NetBeans Project Sample Module Tutorial

This tutorial demonstrates how to create a module that adds a sample to the New Project wizard. The sample could function either as an example to the user or as a new project template that provides the basic files needed to get started working on a technology of some kind.

NOTE: This document is for the 6.7 release of the NetBeans Platform and beyond. If you are using an earlier version, see  link:60/nbm-projectsamples.html[the 6.0/6.1 version of this document].


== Introduction to Project Samples

Using two wizards in the IDE—the New Module Project wizard and the New Project Template wizard—you can very easily create a module that contains your technology's project samples. No coding of any kind is needed in order to do this. The wizards do all the work for you. In fact, if you find yourself doing any coding at all, you are possibly doing something wrong. Coding should only be necessary in a small set of corner cases.

When you complete this tutorial, you will have a module that contains your samples. The intended users of your samples can then simply use the Plugin Manager to install the module. As a result, the samples will appear in the New Project wizard.

At the end of this tutorial, the New Project wizard will contain a new sample, called "My Sample Application":


image::images/mysample_new-project-wizard-60.png[]

In addition to showing how to create a module containing a sample, you will be instructed on some ancillary topics, such as how to change the icon and description in the New Project wizard, and how to regenerate the sample after modifying its sources.


== Creating the Module Project

We begin by working through the New Module Project wizard. At the end of it, we will have a basic source structure, with some default files, that every NetBeans module requires.


[start=1]
1. Choose File > New Project (Ctrl+Shift+N). Under Categories, select NetBeans Modules. Under Projects, select Module. Click Next.

[start=2]
1. In the Name and Location panel, type  ``AdditionalSamples``  in the Project Name field. Change the Project Location to any directory on your computer. Leave the Standalone Module option and Set as Main Project checkbox selected. Click Next.

[start=3]
1. In the Basic Module Configuration panel, type  ``org.myorg.additionalsamples``  in Code Name Base.

[start=4]
1. Select "Generate XML Layer". Leave the locations of both the localizing bundle and the XML layer file so that they will be stored in a package with the name  ``org/myorg/additionalsamples`` . Click Finish.

The IDE creates the  ``AdditionalSamples``  project. The project contains all of your sources and project metadata, such as the project's Ant build script. The project opens in the IDE. You can view its logical structure in the Projects window (Ctrl-1) and its file structure in the Files window (Ctrl-2).


== Bundling the Sample Application

Now that we have a module project, which gives us our source structure, we simply run through another wizard that will bundle our sample. You simply need to select it in the wizard and then the wizard will generate all the required classes and registration details for you.


[start=1]
1. Right-click the project node and choose New > Other. Under Categories, select NetBeans Module Development. Under Projects, select Project Template. Click Next.

[start=2]
1. In the Select Project panel, select the project that you want to bundle as a sample, as shown below.


image::images/mysample_select-project-panel-60.png[]

NOTE:  Only projects that are open in the IDE are shown in the Project drop-down above. To bundle an external project as a sample, use the Browse button to locate it in your filesystem.

Click Next.


[start=3]
1. In the Name and Location panel, type  ``MySampleApplication``  as the template name, type  ``My Sample Application``  as the display name, and select Samples|General in the Category drop-down, as shown below:


image::images/mysample_name-and-location-panel-60.png[]


[start=4]
1. Click Finish.

The IDE creates the following:

*  ``MySampleApplicationProject.zip.``  A ZIP file containing your sample.
*  ``MySampleApplicationDescription.html.``  An HTML file for the description displayed in the New Project wizard's description field.
*  ``MySampleApplicationPanelVisual.``  
 ``MySampleApplicationWizardIterator.java.`` 

 ``MySampleApplicationWizardPanel.java.`` 
A  ``JPanel`` , with a supporting wizard class, and an iterator used in the New Project wizard to create the sample. You do not need to understand how these work, unless you want to. Later in this tutorial, these classes are discussed, although they are not necessary to understand in most scenarios involving the creation of project samples.

In addition, the IDE registers the sample in the XML layer file and adds localization strings to the  ``Bundle.properties``  file.

The Projects window should now look as follows:


image::images/mysample_final-projects-window-60.png[]


== Building and Installing the Module

The IDE uses an Ant build script to build and install your module. The build script is created for you when you create the module project.


=== Installing the NetBeans Module

In the Projects window, right-click the  ``AdditionalSamples``  project and choose Install/Reload in Target Platform.

The module is built and installed in the target IDE or Platform. The target IDE or Platform opens so that you can try out your new module. The default target IDE or Platform is the installation used by the current instance of the development IDE.

NOTE:  When you run your module, you will be using a temporary test user directory, not the development IDE's user directory.


=== Using the NetBeans Module

In this section, we take on the role of the user of our sample. After a user installs our module, they typically take the steps outlined below.


[start=1]
1. Choose File > New Project (Ctrl-Shift-N).

The New Project wizard opens and displays the new project sample:


image::images/mysample_new-project-wizard-60.png[]


[start=2]
1. Select the new project sample and click Next. The wizard panel appears:


image::images/mysample_new-project-wizard2-60.png[]


[start=3]
1. Type a name in the project name field. Click Finish.

The Projects window opens and displays the newly created project sample.


=== Creating a Shareable Module Binary

To make our sample available to our users, we need to create an NBM file, which is a binary NetBeans module file, containing our sample, together with supporting files such as the  ``layer.xml``  file.


[start=1]
1. In the Projects window, right-click the  ``AdditionalSamples``  project and choose Create NBM.

The NBM file is created and you can view it in the Files window (Ctrl-2):


image::images/mysample_shareable-nbm-60.png[]


[start=2]
1. Make it available to others via, for example, e-mail. Or create your own NetBeans Update Center and publish it there. Or publish it in the  link:http://plugins.netbeans.org/PluginPortal/[NetBeans Plugin Portal].


== Tweaking the Sample

In this section, we perform some typical tasks that you might want to perform after completing the New Project Template wizard, in order to finetune your sample. For example, you might want to change the sample's icon, description, and similar items.


=== Changing the Icon

First, we change the default icon, after looking at how the icon is defined for other samples.


[start=1]
1. When you expand the Important Files node, and then the XML Layer node, a node is found, representing the sample's registration in the  ``layer.xml``  file. By right-clicking the node, you can choose Pick Icon, which lets you choose an icon to replace that which is provided by default:


image::images/mysample_image-picker-60.png[]


[start=2]
1. Choose a new icon. When you do so, the  ``layer.xml``  file reflects your new choice:

[source,xml]
----

<folder name="Templates">
    <folder name="Project">
        <folder name="Samples">
            <folder name="Standard">
                <file name="MySampleApplicationProject.zip" 
                                url="MySampleApplicationProject.zip">
                    *<attr name="SystemFileSystem.icon" 
                                urlvalue="nbresloc:/org/myorg/additionalsamples/new_icon.png"/>*
                    <attr name="SystemFileSystem.localizingBundle" 
                                stringvalue="org.myorg.additionalsamples.Bundle"/>
                    <attr name="instantiatingIterator" 
                                methodvalue="org.myorg.additionalsamples.
                                MySampleApplicationWizardIterator.createIterator"/>
                    <attr name="instantiatingWizardURL" 
                                urlvalue="nbresloc:/org/myorg/additionalsamples/
                                MySampleApplicationDescription.html"/>
                    <attr name="template" boolvalue="true"/>
                </file>
            </folder>
        </folder>
    </folder>
</folder>
----

You can also manually change the icon, by adding it to your module, and changing its name in the  ``layer.xml``  file shown above.


[start=3]
1. In the  ``<this layer in context>``  node, visible in the screenshot above, you can see the other samples available to your platform. When you do so, you can choose Open Layer File(s), which opens a node's  ``layer.xml``  file which, in this case, is useful in ascertaining how other samples' icons are defined:


image::images/mysample_image-picker-layers-60.png[]

In the case of the above, in other words, for Java SE samples, the icon is defined as follows:


[source,java]
----

<attr name="SystemFileSystem.icon" 
    urlvalue="nbresloc:/org/netbeans/modules/java/examples/resources/j2seProject.gif"/>
----

If you add the line above to your  ``layer.xml``  file, your sample will have the same icon as the other samples in the New Project wizard's Samples|General category.


=== Changing the Category

When we used the New Project Template wizard, we assigned the sample to a category. Afterwards, we can put it in a different category, either via the user interface shown in the previous screenshot or manually in the  ``layer.xml``  file.


=== Changing the Description

Next, we change the sample's description, which is shown in the New Project wizard. As with the icon, a default description is provided when you create a module containing a sample. However, you can easily change that description.


[start=1]
1. Open the file shown below and notice the default text shown in the editor:


image::images/mysample_description-change.png[]


[start=2]
1. Change the text, reinstall the module, and notice the changed description in the New Project wizard.


=== Changing the Iterator

The New Project Template wizard creates a very basic wizard that the user will work through when getting the sample from the New Project wizard. The wizard is basic in the sense that it consists of one panel and that the panel contains the absolute bare minimum in terms of Swing components. In this section, we look at an easy yet powerful way of changing the single panel, without touching the panel itself.


[start=1]
1. Open the  ``layer.xml``  file and notice the highlighted line below:

[source,xml]
----

<folder name="Templates">
    <folder name="Project">
        <folder name="Samples">
            <folder name="Standard">
                <file name="MySampleApplicationProject.zip" 
                            url="MySampleApplicationProject.zip">
                    <attr name="SystemFileSystem.icon" 
                            urlvalue="nbresloc:/org/myorg/additionalsamples/new_icon.png"/>
                    <attr name="SystemFileSystem.localizingBundle" 
                            stringvalue="org.myorg.additionalsamples.Bundle"/>
                    *<attr name="instantiatingIterator" 
                            methodvalue="org.myorg.additionalsamples.
                            MySampleApplicationWizardIterator.createIterator"/>*
                    <attr name="instantiatingWizardURL" 
                            urlvalue="nbresloc:/org/myorg/additionalsamples/
                            MySampleApplicationDescription.html"/>
                    <attr name="template" boolvalue="true"/>
                </file>
            </folder>
        </folder>
    </folder>
</folder>
----

That line defines an _iterator_, which is a class that implements  `` link:http://bits.netbeans.org/dev/javadoc/org-openide-dialogs/org/openide/WizardDescriptor.ProgressInstantiatingIterator.html[WizardDescriptor./*Progress*/InstantiatingIterator]`` . The iterator specifies the classes that define the panels in the wizard, defines the text of the steps shown in the wizard, unzips the ZIP file, and applies the user-specified settings in the wizard to the unzipped objects in the ZIP file.

The iterator that is found in our  ``layer.xml``  file by default makes use of a  ``JPanel``  and wizard class that are also created by the New Project template wizard.

In the next step, we change the iterator referenced in the  ``layer.xml``  file to the iterator used by other samples. When we do so, we will make use of a different iterator, which will result in the panel in the wizard showing different content.


[start=2]
1. As shown in step 3 of the section called <<icon,Changing the Icon>>, use the "Open Layer File(s)" menu item to open the layer file of one of the other Samples|General category. Replace the iterator defined in your  ``layer.xml``  file with the iterator defined there.

You should find that the iterator is defined as follows:


[source,java]
----

<attr name="instantiatingIterator" 
    newvalue="org.netbeans.modules.java.examples.J2SESampleProjectIterator"/>
----


[start=3]
1. Having made the change outlined above, reinstall the module and notice that the sample's wizard panel now looks as follows:


image::images/mysample_set-as-main-project.png[]

Compare this panel to the screenshot in step 2 of <<using-the-nbm,Using the NetBeans Module>> and notice that we now have a new "Set as Main Project" checkbox, which we did not have when we were using our default iterator. The reason for this is that our default iterator made use of a panel that does _not_ have that checkbox.


=== Adding a Panel

In the previous section, we changed the iterator, which resulted in a different panel being shown. Possibly, however, there is no existing iterator to cater to your specific needs. In this section, we learn how to add a new panel to the wizard. We do this by reusing the iterator that the New Project Template wizard creates for us.


[start=1]
1. Use the Wizard wizard to create a new wizard panel which, just like the panel created by the New Project Template wizard, consists of a  ``JPanel``  and a wizard class.

[start=2]
1. Instantiate the new wizard panel in the iterator's  ``createPanels()``  method, as shown here:

[source,java]
----

private WizardDescriptor.Panel[] createPanels() {
    return new WizardDescriptor.Panel[] {
        *//This is the wizard panel, created by the
        //New Project Template wizard:*
        new MySampleApplicationWizardPanel()
        *//This is the new wizard panel, created by the
        //New Wizard wizard:*
        //new MySampleApplicationWizardPanel1()
    };
}
----

You only need to add your new wizard panel to the method above, and then it will be instantiated when the sample's wizard is invoked by the user in the New Project wizard.


[start=3]
1. Finally, you need to add a new string to the iterator's  ``createSteps()``  method, so that your new wizard panel is accompanied by a string in the left sidebar of the wizard:

[source,java]
----

private String[] createSteps() {
    return new String[] {
        NbBundle.getMessage(MySampleApplicationWizardIterator.class, "LBL_CreateProjectStep"),
        *NbBundle.getMessage(MySampleApplicationWizardIterator.class, "LBL_CreateProjectStep1")*
    };
}
----

You only need to add the line in bold above, and then define the key/value pair in the  ``Bundle.properties``  file.


=== Updating the Sources

When you change the sample's sources, how do you update the module that bundles the sample? Do you need to recreate the module project, work through the New Project Template wizard again, and then recreate the NBM file? No. The only part of the sample module project that is impacted by changes in the original sample's sources is the ZIP file. The ZIP file contains the sources, and those are the only pieces that are affected when you make changes to the original project. Hence, you simply need to recreate the ZIP file. To simplify this, if you add the following Ant target to the  ``build.xml``  file of the project where you created the sources, you can regenerate the ZIP file from inside the IDE and automatically have it copied to the sample module's source structure right away.


[source,xml]
----

<target name="zipme" description="Zip the application to the sample project">
    <property name="build.classes.dir" location="/home/NetBeansProjects/AdditionalSamples"/>
    <property name="examples" location="${build.classes.dir}/src/org/myorg/additionalsamples/"/>
    <zip basedir="../MySampleApplication" destfile="${examples}/MySampleApplicationProject.zip">
        <exclude name="**/build/"/>
        <exclude name="**/dist/"/>
        <exclude name="**/nbproject/private/"/>
    </zip>
</target>
----

In the above Ant target, the  ``build.classes.dir``  property points to the location of your sample module project, which is probably different in your scenario than is indicated above.

NOTE:  We exclude some folders from the ZIP file, because these are not needed in the sample module project and, in fact, would cause problems if they were not excluded.

link:http://netbeans.apache.org/community/mailing-lists.html[Send Us Your Feedback]


== Next Steps

For more information about creating and developing NetBeans modules, see the following resources:

*  link:https://netbeans.apache.org/kb/docs/platform.html[Other Related Tutorials]
*  link:http://bits.netbeans.org/dev/javadoc/[NetBeans API Javadoc]