Thiết kế web với joomla 1.6(5).x part 62 ppsx

Extending Your Site IN THIS CHAPTER Finding extensions Working with the Extension Manager Finding the right extension for the job One of the strengths of the Joomla!. Extensions Director

Extending Your Site

IN THIS CHAPTER

Finding extensions Working with the Extension Manager

Finding the right extension for the job

One of the strengths of the Joomla! system is the ready availability of

a large number of extensions You can find a Joomla! extension for

just about any purpose you can imagine

An extension can be something as simple as a plugin that improves your

search, to something as complex as a complete ecommerce catalog

manage-ment and shopping cart functionality Extensions can simply enhance

exist-ing functionality or add completely new functionality; they can also be

purely aesthetic in the case of templates

This chapter covers how to find extensions and how to install and uninstall

them This chapter also takes a look at some of the most popular extensions

Finding Extensions

Joomla! extensions can be found in a number of locations, from the

develop-ers’ web sites to various extension directories Two officially maintained

directories are JoomlaCode and the Joomla! Extensions Directory The

Joomla! Extensions Directory is shown in Figure 22.1

The JoomlaCode site serves as a code repository and distribution point for

non-commercial extensions The site hosts over 2,000 extensions, organized

into categories and sub-categories that can be browsed or searched

JoomlaCode does not include reviews or ratings and can be tough to use

The structure of the site makes it a challenge to find things, unless you

already know what you are looking for!

FIGURE 22.1

The official Joomla! Extensions Directory web site Note the directory tree at the bottom of the page

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The Joomla! Extensions Directory is located at

http://extensions.joomla.org

The most popular and easiest to use source of Joomla! extensions is the Joomla! Extensions Directory The site lists nearly 4,500 extensions that can be downloaded and installed on your Joomla! site The Joomla! Extensions Directory was purpose-built by the Joomla! team to provide a browsable directory of extensions Each extension is classified and described Information includes user reviews and ratings as well as indications of download volume and popularity, as shown in Figure 22.2 The additional information and feedback provided with the listings is invaluable, given the large number of options you face

All the extensions on the Joomla! Extensions Directory are released under the open source GPL license The majority of the extensions are free of charge, although some are commercial The listings in the extensions directory identify the developer or company behind the extension and provide links to the developer’s web site and to support and documentation resources, if any The Joomla! Extensions Directory is organized like most directories, with a tree of categories and subcategories that can be browsed topically You can also browse the extensions based on ratings, views, and popularity, or you can view the newest or most reviewed extensions

Additionally, the site includes both a basic and an advanced search functionality at the top right

of each page The advanced search is particularly useful because it allows you to filter by version compatibility

Caution

Make sure that you download only extensions that are compatible with your version of Joomla! Extensions written for Joomla! 1.0 are typically not compatible with Joomla! 1.5 The versions they are compatible with are shown in the heading of each extension.

Note that unlike JoomlaCode, the Joomla! Extensions Directory does not host any of the down-loads Therefore, when you click to download an extension, you are taken to a different site Sometimes, the downloads are hosted on JoomlaCode, but many other times the files are hosted on the developer’s Web site Note also that some developers may require you to register on their site before you can download the Extension files

FIGURE 22.2

A typical listing on the Joomla! Extensions Directory

FIGURE 22.2 (continued)

Both JoomlaCode and the Joomla! Extensions Directory contain a wide variety of components, mod-ules, plugins, toos, l and language packs; however, neither of the official sites includes templates for your Joomla! site As a direct result of this omission, a large number of template providers have jumped

in to fill the gap Following is a list of some of the more popular template sites The list includes both commercial and noncommercial templates, but you should note that many of the sites that offer free templates typically expect promotional exposure on your site by means of links back to their web sites

on the template

Dream Template

www.dreamTemplate.org

Dream template provides more than 4,000 web designs They provide designs only, not ready to use Joomla! templates, so you will have to do the conversion work yourself before you can use them in Joomla! Prices vary widely, depending largely on whether you want exclusive rights to the design

Open Source Web Design

www.oswd.org

This site is home to over 2,000 web designs, all free of charge They provide designs only, not ready to use Joomla! templates Although many designs are here and it is all free of charge, site activity has been very low over the last couple of years and the catalog is starting to look rather dated

Template Monster

www.Templatemonster.com

With a catalog of over 12,000 designs, Template Monster is perhaps the largest of the commercial tem-plate providers Temtem-plate Monster includes more than 200 ready-to-use Joomla! temtem-plates Prices vary widely, depending largely on whether you want exclusive rights to the design

Rocket Themes

www.rockettheme.com

This group specializes in ready to use Joomla! and phpBB templates The number of designs is more limited, but the templates themselves are some of the most flexible and functional Joomla! templates in the market They have recently introduced templates tailored for the VirtueMart e-commerce system for Joomla!

Finding Joomla! templates

Working with the Extension Manager

Extensions are managed through the admin system, by way of the Extension Manager The manager enables you to install, uninstall, enable, and disable all the extensions on your site

Introducing the Extension Installer

In Joomla! 1.5.x, access the Extension Installer by going to the Extensions menu and selecting the option Install/Uninstall The Extensions Installer interface loads in your browser, as shown in Figure 22.3

FIGURE 22.3

The Joomla! 1.5.x Extension Installer interface

Six links are below the toolbar:

l Install shows you the Install screen.

l Components shows you the components installed on your system.

l Modules shows you the modules installed on your system.

l Plugins shows you the plugins installed on your system.

l Languages shows you the language packs installed on your system.

l Templates shows you the templates installed on your system.

Joomla! 1.6

The Extension Manager has been revised and simplified in Joomla! 1.6 The changes begin with the Extensions menu Gone is the option Install/Uninstall, replaced with the more descriptive term Extension Manager Clicking on the Extension Manager takes you to the Extension Installer dialogue The dialogue in Joomla! 1.6 serves exactly the same purpose as it did in 1.5 Note that the links below the toolbar have been simplified from six links to five links The new links are Install, Update, Manage, Discover, and Warnings.

Going over the Extension Packages dialogue

In Joomla! 1.5.x, each type of extension is the subject of a different interface, as shown in

Figure 22.4

The toolbar at the top of the Extension Manager provides quick access to the following functions:

l Uninstall: Select one or more extensions from the list, then click this icon to uninstall it.

l Help: Click to access the online Help files related to the active screen.

Below the toolbar are the same six links as on the Install screen

Below the links and above the list of templates you will note the system-generated reminder mes-sage that only certain templates can be removed; those that are necessary for the system to function cannot be uninstalled

FIGURE 22.4

The Joomla! 1.5.x Extension Packages interface, showing the templates; this screen is typical of all the individual extension packages in Joomla! 1.5.x

The main content area of the screen contains a list of all the templates in your Joomla! site The columns provided are:

l #: An indexing number assigned by Joomla! This cannot be changed.

l Checkbox (no label): Click in a checkbox to select a template; this is needed if you want

to use several of the toolbar options, referenced in the preceding section

l Template: This field displays the full name of the template.

Finally, at the bottom of the screen, below the content area, is the Display # option Change the value in the combo box control to alter the number of templates that are displayed on the page The default value can be altered by changing the List Length option on the Global Configuration Manager

Installing extensions

The Extension Installer interface, (refer to in Figure 22.3), provides three alternative methods for installing extensions for your site The three methods are:

l Install from a package file

l Install from a directory

l Install from an URL

You only need to use one method to install an extension, and you will likely use the same method for the life of your site The selection of method is largely a by-product of the nature and location

of the extension files you need to install

Installing from a Package File

This is the normal way to install an extension Most users find that this method handles all their needs To install a new extension from a package file, follow these steps:

1 Download the extension’s archive file to your local computer.

2 Log in to the admin system.

3 Access the Extensions Installer dialogue by clicking on the option Install/Uninstall

under the Extensions menu The Extensions Installer loads in your browser window.

4 Click the Browse button The File Upload dialogue opens.

5 Locate the extension’s archive file on your local computer Click on it and then click

the Open button The pop-up menu closes, and you should see the name of the

exten-sion archive file in the Package File: field

6 Click Upload File and Install The system attempts to install the extension and if

suc-cessful, you can see a confirmation message

Installing from a directory

Installing from a directory is used when you need to unarchive the files before you move them to the server, or if you have been given the files in unarchived form To install a new extension from a directory, follow these steps:

1 Download the extension’s archive file to your local computer.

2 Unarchive the files locally.

3 Log into your server by FTP or via your web host file manager.

4 Move the extension directory and files up to your server, noting the location A safe

place to put this is the tmp folder

5 Log in to the admin system of your Joomla! site.

6 Access the Extensions Installer dialogue by clicking on the option Install/Uninstall

under the Extensions menu The Extensions Installer loads in your browser window.

7 Type name address of the directory on the server that contains the extension files

into the field label Install Directory.

8 Click the Install button The system attempts to install the wxtension and if successful,

you will see a confirmation message

Installing from an URL

Installing from a URL is used in situations where you can access the archive file directly on another server and do not need to download it to your local machine first You can use this, for example, to install archives directly from the JoomlaCode web site To install a new extension from a URL, fol-low these steps:

1 Locate the extension’s archive file on the remote computer, noting the URL.

2 Log in to the admin system.

3 Access the Extensions Installer dialogue by clicking on the option Install/Uninstall

under the Extensions menu The Extensions Installer loads in your browser window.

4 Type the extension archive file’s URL into the field labeled Install URL.

5 Click the Install button The system attempts to install the extension and if successful,

you will see a confirmation message

Uninstalling extensions

To uninstall an extension in Joomla! 1.5.x, follow these steps:

1 Log in to the admin system.

2 Access the Extensions Installer dialogue by clicking on the option Install/Uninstall

under the Extensions Menu The Extensions Installer loads in your browser window.

Joomla! 1.6

Uninstalling an extension in Joomla! 1.6 is slightly different, due to a change in labels and controls The Uninstall icon is now located on the Manage dialogue, inside the Extension Manager In all other regards, the process is the same.

Caution

Deleting an extension is permanent and cannot be undone Uninstalling will also typically wipe out any data

on the extension from the database If you want to use the extension again, you must reinstall it.

Finding the Right Extension for the Job

Perhaps one of the most daunting parts of using extensions is finding the right tool for the job Thousands of extensions are available and sometimes you are faced with multiple options that appear to achieve your goals Although there really is no substitute for downloading things and trying them out yourself, in this chapter I provide a list of extensions that are a good starting point for addressing common needs

Note that I am not endorsing one particular extension over another, but rather simply listing resources to help you get started The list includes both commercial and noncommercial exten-sions Note also that this list was created for Joomla! 1.5.x and that you must always be certain that the extensions you download and install on your site are compatible with your version of the core Caution

The rate of change in the open source world can be daunting Developers change, projects fork, some projects get abandoned It’s impossible to say what will be here in 12 months’ time One thing is certain: The extensions provided in this list will change over time You should always keep this in mind when you are selecting exten-sions, and if business risk is an issue for you, then you need to do your own research and consider carefully which extensions you adopt.

Improving content management

The extensions listed here all expand upon Joomla!’s default Content Management functionality The list includes both extensions to enhance existing articles as well as several powerful tools for changing the nature of the articles and the article-editing functionality

AllVideos Reloaded

http://joomlacode.org/gf/project/allvideos15/

This component enables the embedding and displaying of videos on your web site The compo-nent comes in multiple parts: a content plugin, an editor plugin, a system plugin, and a module Once installed, you can display video files either inside of articles or inside module positions, or as

a pop-up window inside a lightbox The most recent version also includes a utility to convert vari-ous video formats in flv (flash video) files This extension is non-commercial