关于用来扩展Joomla功能的三大件Components、Modules和Plug-Ins的区别：
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显示在页面的”主要”部分. 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与元件比较起来，一个页面上可以显示多个模組. 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网站中到处运行的一段代码, 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.
Joomla!'s
Component Structure Joomla! employs a specific naming
scheme, which is used by all components. Each component in the
system has a unique name with no spaces. The code is split into two
folders, each bearing the component name prefixed by com_.
The component in this book will be called reviews.
Therefore, you will have to create two folders named com_reviews:
· Create
one in the folder named components
for the front end.
· Create
one in the folder named components
within the administrator
folder
for the back end.
When
the component is loaded from the front end, Joomla! will look for a
file with the component's unique name ending in a .php
extension. Within the components/com_reviews
folder, create the reviews.php
file. Similarly, running it in the back end assumes the presence of
a file prefaced with admin.
followed by the component name and ending in .php.
Add the file admin.reviews.php
in administrator/components/com_reviews.
Leave both the files empty for the moment.
Executing
the Component All
front-end requests in Joomla! go through index.php
in the root directory. Different components can be loaded by setting
the option variable in
the URL GET string. If you install Joomla! on a local web server in
a directory titled joomla,
the URL for accessing the site will be
http://localhost/joomla/index.php
or something similar. Assuming this is the case, you can load the
component's front end by opening
http://localhost/joomla/index.php?option=com_reviews
in your browser. At this point, the screen should be essentially
blank, apart from the common template elements and modules. To make
this component slightly more useful, open reviews.php
and add the following code, then refresh the browser:
<?php
defined( '_JEXEC' ) or die( 'Restricted access' ); echo '<div
class="componentheading">Restaurant Reviews</div>';
?>
Your
screen will look similar to the following:
以下是Joomla1.0.x版本，请在后面看joomla1.5.x的模板例子!
The
Joomla! Template
First,
let's look at the following figure to see how our basic template
affects the Joomla! PHP output:
Figure
2.1 What your XHTML does to the template layout
You'll
recall that the PHP code for the footer,
sitename,
pathway,
and MainBody
are not module position
slots. These functions load in the required information that helps
Joomla! to run, display standard footer information, and load the
actual site content from the Joomla! MySQL databases
Top,
left, and right
are module position
slots, which can be assigned site
modules.
模板(template)决定module
slots的位置
和 component(组件)的位置(同一时刻只显示一个component,就是前面Jommla1.0.x的<?php
mosMainBody();?>和后面Jommla1.5.x的模板中的<jdoc:include
type="component" />)
Now
that we have a deeper understanding of how the template, module
position slots, and site modules work, let's take a look at how
these three elements come together through the rhuk_solar_flare_ii
template. The module position slot name is on the left, the content
module name is on the right,
举例：CEF的首页模板joomla1.5.2/templates/gian_idv_tw/index.php内容:
<html>
<head>
<jdoc:include
type="head" />
<link
href="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/images/CSS.css"
rel="stylesheet" type="text/css">
<!--
<script
language="JavaScript" src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/Scripts/menu.js"></script>
-->
<script
language="JavaScript" src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/Scripts/swapimage.js"></script>
<script
language="JavaScript" src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/mm_menu.js"></script>
<script
src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/Scripts/AC_RunActiveContent.js"
type="text/javascript"></script>
<link
href="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/images/hotnews.css"
rel="stylesheet" type="text/css">
<script
type="text/JavaScript">
<!--
function
MM_popupMsg(msg) { //v1.0
alert(msg);
}
//-->
</script>
<?php
include("templates/CEF/menu.php");
?>
</head>
<?php
if
( $my->id ) {
//initEditor();
}
?>
<body
leftmargin="0" topmargin="0" marginwidth="0"
marginheight="0" onLoad="MM_preloadImages('<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/button_search_2.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_23_1.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_24_1.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_25_1.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/button_re_2.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/button_send_2.gif','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_10_1.jpg','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_11_1.jpg','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_12_1.jpg','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_13_1.jpg','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_14_1.jpg','<?php
echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_15_1.jpg')">
<script
language="JavaScript1.2">mmLoadMenus();</script>
<div
id="main">
<div
class="header">
<div
class="top_left">
<div
class="logo">
<embed
src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/logo.swf"
quality="high" wmode="transparent"
bgcolor="#ffffff" allowscriptaccess="sameDomain"
pluginspage="http://www.macromedia.com/go/getflashplayer"
type="application/x-shockwave-flash" align="middle"
height="174" width="341"/>
</div>
</div>
<div
class="top_right">
<?php
include("templates/CEF/web_links.php");
?>
<div
id="searchbar">
<?php
include("templates/CEF/search_bar.php");
?>
</div>
<div
id="menubar">
<?php
include("templates/CEF/menubar.php");
?>
</div>
</div>
</div>
<div
class="main_content">
<div
class="main_left">
<table
border="0" align="left" cellpadding="0"
cellspacing="0">
<tr>
<td
rowspan="3" valign="top"><img src="<?php
echo $this->baseurl;?>/templates/gian_idv_tw/images/index_19.gif"
width="17" height="194" alt=""></td>
<td><img
src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_20.gif"
width="225" height="12" alt=""></td>
</tr>
<tr>
<td
class="bg_left_table"><div align="left"><img
src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_30.gif"
width="225" height="35" alt="">
<!--教育新闻台-->
<?php
if($this->countModules('user1')) : ?>
<jdoc:include
type="modules" name="user1" style="xhtml"
/>
<?php
endif; ?>
<?php
if($this->countModules('left')) : ?>
<jdoc:include
type="modules" name="left" style="rounded"
/>
<?php
endif; ?>
</div></td>
</tr>
<tr>
<td
height="13" valign="bottom"
class="bg_left_table"><img src="<?php echo
$this->baseurl;?>/templates/gian_idv_tw/images/index_54.gif"
width="225" height="13" alt=""></td>
</tr>
</table>
</div>
<div
class="main_right">
<table
width="684" border="0" cellspacing="0"
cellpadding="0">
<tr>
<td bgcolor="#FFFFFF">
<!--标签页-->
<?php
if($this->countModules('user2')) : ?>
<jdoc:include
type="modules" name="user2" style="xhtml"
/>
<?php
endif; ?>
</td>
<td>
<?php
include("templates/CEF/right_ad.php");
?>
<!--<iframe
id="ad" name="ad" src="link_button.html"
width="182" height="194" scrolling="no"
frameborder="0"></iframe>-->
</td>
</tr>
</table>
<table
width="684" border="0" cellspacing="0"
cellpadding="0">
<tr>
<td>
<!--2x2方框-->
<jdoc:include
type="component" />
</td>
</tr>
<!--picture
banner-->
<?php
if($this->countModules('user3')) : ?>
<jdoc:include
type="modules" name="user3" style="xhtml"
/>
<?php
endif; ?>
</table>
</div>
<div
id="footer"><br><br>
Copyright
(C)2005 Campus Evangelical Fellowship All Rights Reserved. ．校園福音團契
版權所有． E-mail：<a
href="mailto:info@cef.org.tw">info@cef.org.tw</a>
．
電 話：(02)
2368-2361 ．傳
真：(02)
2367-2139</div><div id="space"></div>
</div>
</div>
<jdoc:include
type="modules" name="debug" />
</body>
</html>