JOOMLA EXTENSION (2nd POST)

Topic Overview
This book will cover the following topics regarding developing extensions
for Joomla!.
Creating Toolbars and List Screens
Joomla! has a standard set of toolbar buttons used throughout the back end. These
keep a consistent appearance across components, so users quickly become familiar
with the corresponding functions. When necessary, the labeling and functions of
these buttons can be changed and new buttons can also be added.
Like the standard toolbars, Joomla! has a certain look for screens that list a set of
records from the database. These lists usually have links to edit screens for the
individual records and have toggles that change the publishing status of the record.
Automatic pagination is also available for lists.
Maintaining a Consistent Look and Reducing
Repetitive Code Using HTML Functions
Several standard CSS class names are used to format content and HTML elements
within your extensions. This makes it easy for your extensions to seamlessly blend in
with the rest of the website. Additionally, Joomla! includes many functions to automate
the generation of checkboxes, dropdowns, select lists, and other common elements.
Accessing the Database and Managing
Records
A common database object is used in Joomla! so that only one connection is made
during every page request. This object also provides a set of functions to make
queries and retrieve results. These functions are database independent and are
designed in such a way that you can install multiple copies of Joomla! into the same
database when desired.
Besides a common database object, Joomla! has a standard database table class.
Records can be created, read, updated, and deleted using the core functions. Logic
can also be added so that child records in other tables are deleted when the parent
is removed.
Security and the Preferred Way of Getting
Request Variables
Since Joomla! is a web application deployed within public reach, it is necessary
to protect it against security vulnerabilities. Joomla! employs a common
method of making sure scripts are only called within the framework and not
randomly executed.
Besides unintended script behavior, maliciously submitted data can be used by
hackers to gain access to your database. Joomla! provides functionalities that prevent
attacks of this kind.
Menu Item Control
A noteworthy feature of Joomla! is that navigation is separated from content.
However, if a component is not built to take this into account, it is possible that
website administrators will lose their template and module selections. To take
advantage of the system, it is necessary to use the intended menu item ID number in
generated links.
Also, it is possible to give administrators multiple options for linking to your
component. This will allow the choice of different display options for the front end
without the need to construct long, confusing URLs by hand. These options can
additionally offer admins some simple configuration controls.

JOOMLA EXTENSION DEVELOPMENT(AN OVERVIEW)

You have developed dynamic websites in the past, but a friend of yours told you
about Joomla!, so you decide to give it a try. You wish to start a simple website
about restaurants after being inspired by the attractive celebrity chefs from the
Food Network. The installation goes smoothly and more quickly than attempting
to build a content management system from scratch. After finding a delicious
template, adding some menus, and banging out a couple of reviews, you begin to
think of some of the features that will draw in more visitors and even some cash.
Within minutes, you install a shopping cart for selling books, a forum for gathering
suggestions of places to review, and some advertising affiliated programs for
the sidebars.
However, as you glance through the homepage, you feel something is missing. Then
suddenly a brilliant idea hits you for something entirely new. Once it is finished,
you know others will want to use it for their sites as well. You look around
Joomla!'s source files and start looking for a way of building code that will slide
right into place.

Why Extend Joomla!
Joomla! is not only designed to handle the content articles, but also to allow a
number of complex applications to be cleanly integrated. Shopping carts, forums,
social networking profiles, job boards, and real estate listings are examples of
extensions that the developers have written for Joomla!. All of these can run on a
Joomla! site, and only a single database, template, and core need to be maintained.
When you build an extension to Joomla!, it will inherit the look and feel of the
overall site. Any type of program that can be coded in PHP is a potential component
waiting to be written.
Your extensions can also be portable. When coded correctly, you will easily be able
to install your code on another copy of Joomla! without having to enter the database
logins and other basic configuration information again. Additionally, you will be
able to distribute your extensions to others so that they can enjoy them, without any
programming or database knowledge.
Customization versus Extension
Joomla!'s code is designed to be extended rather than hacked or directly modified.
Rather than changing the core code, it is preferable to write an extension. When
updates and patches are released for Joomla! itself, the core code will be updated,
but your extensions will not be overwritten. These extensions are crafted in a
self‑contained manner, allowing you to freely develop your own code without
disturbing other items present in the Joomla! installation.
Although they are self-contained, extensions do not operate in a completely sealed
environment; you can mix different kinds to get the functionalities you desire.
Joomla!'s code allows extensions to share resources and sometimes perform actions
on each other. Since we can write extensions, we will do this instead of customizing
the core.
How to Extend Joomla!
There are three types of extensions Joomla! supports, each with a specific use.
Components
Of the extensions available, components are the most essential. Components are
essentially what you see in the "main" portion of the page. Joomla! is designed
to load and run exactly one component for each page generated. Consequently,
Joomla!'s core content management functionality is itself a component.
Components frequently have sophisticated back-end controls. The back end is
commonly used to create and update records in database tables; also it can do
typically anything, provided it is programmed in PHP. For instance, you may have
a batch job that typically runs from a UNIX command line, but you can use the back
end to provide a link where non-programmers can call it. You can also use it to allow
site administrators to upload pictures or videos.
Modules
In contrast to components, any number of modules can appear on a page. Modules
typically make up the elements of a sidebar or content menus. Modules complement
the content contained in a component; they are not intended to be the main substance
of a page. Joomla! also supports content modules, which involve no programming
and can be displayed alongside coded components. The back‑end controls for
modules are limited, typically consisting of basic formatting.
Plug-Ins
When a piece of code is needed throughout the site, it is best implemented as a
plug-in (formerly called a Mambot). Plug-ins are commonly used to format the
output of a component or module when a page is built. Some examples of plug-ins
include keyword highlighting, article comment boxes, and JavaScript-based HTML
editors. Plug-ins can also be used to extend the results found in the core search
component. The back-end controls are similar to those of modules.

(The next i post again, so be with us.)

(The Links you get, can be helpful for you.)

About Joomla(1st day)

ABOUT JOOMLA

So, Who you are search this post,interested about this post, want to learn something about joomla. ok. Let's take a look about joomla. actually, joomla is a framework of php. so, for joomla developers the php language is must. In these post(i will try regularly to post something new) i am going to tell about joomla extension programming. we use joomla 1.5. ok?

now, let's start about joomla. joomla has several parts for development. the components, modules and the plugins and also the templates for joomla.

To develop the extensions of joomla(components, modules, plugins) in these posts we just need the php, the xampp.

ok.go forroward.If something missing, you get the information in next. :-)

remember to try everyday what i going to post for you. thanx.

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