J3.x

Developing an MVC Component/Adding a menu type to the site part

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< J3.x:Developing an MVC Component
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Joomla! 
3.x
Tutorial
Developing an MVC Component



This is a multiple-article series of tutorials on how to develop a Model-View-Controller Component for Joomla! VersionJoomla 3.x.

Begin with the Introduction, and navigate the articles in this series by using the navigation button at the bottom or the box to the right (the Articles in this series).



Note[edit]

  • You can follow the steps below to add a menu item to the Hello World! component, or you can directly download the archive

Adding a Menu Item to Hello World[edit]

In this article we will cover how to add a menu item to a basic Joomla! component. For this example we will be continuing our work on the Hello World! component.

There are several ways to update a Joomla! component. As with the last tutorial, we will focus option 2.

1 Manually add the files into <path_to_joomla>/
2 Update using the Joomla! Extension Manager and the original directory, non-compressed, used for the component install
3 Update using the Joomla! Extension Manager and an Update Server

To add a menu item you will need to navigate to com_helloworld, which is the original directory we made for our component. You must use the updated directory structure from the last tutorial. Using your preferred file manager, create or update the following files; as you create or update the files, add the source code for each file which is found in File Details.

1 Create: default.xml <path_to_com_helloworld/site/views/helloworld/tmpl/default.xml
2 Update: helloworld.xml <path_to_com_helloworld/helloworld.xml

Updating the Hello World! Component[edit]

To update the Hello World! Component in the Joomla! website, please follow the same steps for the original installation.

After the component has been updated, we will be able to add a Menu Item to it. This will allow us to access our component a menu rather than having to remember what to type into the address bar. We'll do this using the Menu Manager of Joomla!.

  • Using your preferred web browser, navigate to the Administrator panel of your Joomla! site. The address would be <yoursite>/joomla/administrator/index.php. For this example we will navigate to localhost/joomla/administrator/index.php.
  • Add a new menu item by clicking on Menu    <existing menu>    Add New Menu Item. A new screen will appear.
  • In the "Menu Title" field, enter "Hello World!"
  • In the "Menu Type" field, click on the "Select" button and choose Hello World!    Hello World from the selection screen.
  • Click Save & Close

You should now be able to access the component through the menu that you just created.

File Details[edit]

site/views/helloworld/tmpl/default.xml

<?xml version="1.0" encoding="utf-8"?>
<metadata>
	<layout title="COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_TITLE">
		<message>COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_DESC</message>
	</layout>
</metadata>

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="3.0" method="upgrade">

	<name>Hello World!</name>
	<!-- The following elements are optional and free of formatting constraints -->
	<creationDate>January 2018</creationDate>
	<author>John Doe</author>
	<authorEmail>john.doe@example.org</authorEmail>
	<authorUrl>http://www.example.org</authorUrl>
	<copyright>Copyright Info</copyright>
	<license>License Info</license>
	<!--  The version string is recorded in the components table -->
	<version>0.0.3</version>
	<!-- The description is optional and defaults to the name -->
	<description>Description of the Hello World component ...</description>

	<update> <!-- Runs on update; New since J2.5 -->
		<schemas>
			<schemapath type="mysql">sql/updates/mysql</schemapath>
		</schemas>
	</update>

	<!-- Site Main File Copy Section -->
	<!-- Note the folder attribute: This attribute describes the folder
		to copy FROM in the package to install therefore files copied
		in this section are copied from /site/ in the package -->
	<files folder="site">
		<filename>index.html</filename>
		<filename>helloworld.php</filename>
		<filename>controller.php</filename>
		<folder>views</folder>
	</files>

	<administration>
		<!-- Administration Menu Section -->
		<menu link='index.php?option=com_helloworld'>Hello World!</menu>
		<!-- Administration Main File Copy Section -->
		<!-- Note the folder attribute: This attribute describes the folder
			to copy FROM in the package to install therefore files copied
			in this section are copied from /admin/ in the package -->
		<files folder="admin">
			<!-- Admin Main File Copy Section -->
			<filename>index.html</filename>
			<filename>helloworld.php</filename>
			<!-- SQL files section -->
			<folder>sql</folder>
		</files>
	</administration>
</extension>

Code Explanation[edit]

In case you were curious as to why this works the way it does.

default.xml[edit]

Note - For the moment the strings won't be translated in the administrator interface. We will see in a later article how translation is performed.

helloworld.xml[edit]

<version>0.0.3</version>

Updates the version number.

Component Contents[edit]

At this point in the tutorial, your component should contain the following files:

1 helloworld.xml this is an XML (manifest) file that tells Joomla! how to install our component.
2 site/helloworld.php this is the site entry point to the Hello World! component
3 site/index.html prevents web server from listing directory content
4 site/controller.php file representing the controller
5 site/views/index.html prevents web server from listing directory content
6 site/views/helloworld/index.html prevents web server from listing directory content
7 site/views/helloworld/view.html.php file representing the view
8 site/views/helloworld/tmpl/index.html prevents web server from listing directory content
9 site/views/helloworld/tmpl/default.php the default view
10 site/views/helloworld/tmpl/default.xml file that adds menu item
11 admin/index.html prevents web server from listing directory content
12 admin/helloworld.php this is the administrator entry point to the Hello World! component
13 admin/sql/index.html prevents web server from listing directory content
14 admin/sql/updates/index.html prevents web server from listing directory content
15 admin/sql/updates/mysql/index.html prevents web server from listing directory content
16 admin/sql/updates/mysql/0.0.1.sql file allowing to initialise schema version of the com_helloworld component.