From Joomla! Documentation
Revision as of 15:11, 13 July 2011 by Mvangeest
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- 1 Anchor
- 2 Article
- 3 Cascading Style Sheet (CSS)
- 4 Category
- 5 Chrome
- 6 Component
- 7 Extension
- 8 jdoc
- 9 Legacy Plugin
- 10 Mambot
- 11 Model-View-Controller
- 12 Module
- 13 Module Position
- 14 Module Class Suffix
- 15 MVC
- 16 Page Class Suffix
- 17 Patch
- 18 PHP
- 19 Plugin
- 20 Section
- 21 SEF URLs
- 22 Split menus
- 23 Template
- 24 Upgrade Package
- 25 Version Control Software
<translate> In Joomla! an Article is a piece of content consisting of text (HTML), possibly with links to other resources (for example, images). Articles are the basic units of information in the content system and the bottom level in the content hierarchy. Since Joomla! , each Article is in exactly one Category. A Category can be in another Category making it a sub Category. It is also possible to have Uncategorised Articles. These articles exist without being associated with any Category.
Before Joomla! 2.5 and earlier versions, an Article was the third level in the hierarchy Sections → Categories → Articles. Now an Article is a bottom level and will always be the second level or greater in hierarchy.
- Category → Articles
- Category → sub Category → Articles
- Category → sub Category → sub Category → Articles
Articles are maintained using the Article Manager (see the Content Article Manager for or the Content Article Manager for ) which can be reached in the Administrator (Back-end) by clicking on the Content menu, then the Article Manager menu item.
See also: Category</translate>
Cascading Style Sheet (CSS)
<translate> Every part of Joomla! powered web site or any CMS type of web site needs a method to display and store its content logically. The usual method is by categories and subcategories. Joomla! allows for multiple ways to display and use content controlled by categorisation. Some of the content types which have categorisation are articles (Main content of web pages), banners, contacts and web links.
Joomla! category named "Uncategorised" is the default category, assigned to any and all content types. The "Uncategorised" category is not descriptive and should be used on as needed basis for content types which do not fall under a specific category.
When creating and assigning categories, you should have a planned structure. As an example, this is one way of how you would categorise several Joomla articles on birds. Create two top article categories called "Animals" and "Plants". Under the "Animals" category, you might have sub categories called "Birds" and "Mammals". Under the "Birds" sub category, you might have 3 articles named "Hawks," "Parrots" and "Sparrows".
The example above could be expanded even more with specific articles on different species of Hawks, Parrots and Sparrows. Start with using an "Animal" top Category, placing the sub categories "Birds" and "Mammals" are under the "Animal" category, and then a "Hawks," "Parrots" and "Sparrows" sub category under the "Birds" Sub Category as shown below.
Now you can create multiple articles in the Hawk, Parrot and Sparrow sub categories using the different genus or common names of the specific types of these 3 birds.
Categories and their sub categories are maintained using the "Category Manager" which can be reached in the administrator back-end interface by clicking on the "Content" menu type, then the "Category Manager" menu item for the type.
See also: Article</translate>
<translate> The visible graphical interface features of an application are sometimes referred to as chrome. See Applying custom module chrome for information about how to modify the look of modules (in other words, the module "chrome").</translate>
<translate> A component is a kind of Joomla! extension. Components are the main functional units of Joomla!; they can be seen as mini-applications. An easy analogy would be that Joomla! is the operating system and the components are desktop applications. Created by a component, content is usually displayed in the center of the main content area of a template (depending on the template).
Most components have two main parts: an administrator part and a site part. The site part is what is used to render pages of your site when they are requested by your site visitors during normal site operation. The administrator part provides an interface to configure and manage different aspects of the component and is accessible through the Joomla! administrator application.
Joomla! comes with a number of core components, like the content management system, contact forms and Web Links.
<translate> An extension is a software package that extends your Joomla! installation in some way. A small selection of extensions is included with the default Joomla! installation but many more are available from the Joomla! Extensions Directory.
The term extension is generic and the following specific extension types are available:
- Component (since ) – adds custom functions to your site that can be selected from menus
- Language (since ) – defines an additional language for your site
- Library (since ) – provides functions to be used by other extensions
- Module (since ) – shows nonessential data in a side box, possibly on multiple pages
- Package (since ) – bundles related extensions
- Plugin (since ) – modifies content in articles or provides functions to extend other extensions
- Template (since ) – define the look, feel, and navigation capabilities of your site
For an overview of the most important extension types and the functionality they provide, see Extension types (general definitions).</translate>
<translate> jdoc statements are included in every Joomla template and indicate where the output from other parts of Joomla or its extensions should be positioned in the overall web page. A typical jdoc statement looks like this:
<jdoc:include type="component" /></translate>
Version 1.5 of Joomla! changed the way that third-party Extensions work with the Joomla! core programs. Extensions written for version 1.0 need to be modified in order to use the new 1.5 methodology. To allow for backward compatibility with existing 1.0 Extensions, a Plugin called "System - Legacy" is included with Joomla! 1.5. This Plugin allows many Extensions developed for version 1.0 to work with version 1.5. This Plugin is disabled by default and must be enabled before you can use any Extensions in "Legacy" mode. It can be enabled from the Plugin Manager screen.
Extensions that have been tested by the Extension provider to work using the Legacy Plugin are labeled as "1.5 Legacy". Extensions that use the new 1.5 methodology are labeled as "1.5 Native". In general, "1.5 Native" Extensions will perform somewhat faster than "1.5 Legacy", because the Legacy Plugin requires one extra layer of processing. Over time, it is expected that the majority of Extensions will be available in "1.5 Native" mode.
<translate> Joomla makes extensive use of the Model-View-Controller design pattern.
When Joomla is started to process a request from a user, such as a GET for a particular page, or a POST containing form data, one of the first things that Joomla does is to analyse the URL to determine which component will be responsible for processing the request, and hand control over to that component.
If the component has been designed according to the MVC pattern, it will pass control to the controller. The controller is responsible for analysing the request and determining which model(s) will be needed to satisfy the request, and which view should be used to return the results back to the user.
The model encapsulates the data used by the component. In most cases this data will come from a database, either the Joomla database, or some external database, but it is also possible for the model to obtain data from other sources, such as via a web services API running on another server. The model is also responsible for updating the database where appropriate. The purpose of the model is to isolate the controller and view from the details of how data is obtained or amended.
The view is responsible for generating the output that gets sent to the browser by the component. It calls on the model for any information it needs and formats it appropriately. For example, a list of data items pulled from the model could be wrapped into an HTML table by the view.
Since Joomla is designed to be highly modular, the output from the component is generally only part of the complete web page that the user will ultimately see. Once the view has generated the output, the component hands control back to the Joomla framework which then loads and executes the template. The template combines the output from the component, and any modules that are active on the current page, so that it can be delivered to the browser as a single page.
To provide additional power and flexibility to web designers, who may only be concerned with creating new designs rather than manipulating the underlying code, Joomla splits the traditional view into a separate view and layout. The view pulls data from the model, as in a traditional MVC pattern, but then simply makes that data available to the layout, which is responsible for formatting the data for presentation to the user. The advantage of having this split is that the Joomla template system provides a simple mechanism for layouts to be overridden in the template. These layout overrides (often called "template overrides" because they form part of the template, although actually it is the layout that is being overridden) are bundled with the template and give the template designer complete control over all the output from the Joomla core and any installed third-party extensions that comply with the MVC design pattern.
<translate> Modules are lightweight and flexible extensions used for page rendering. These modules are often “boxes” arranged around a component on a typical page. A well-known example is the login module. Modules are assigned per menu item, so you can decide to show or hide (for example) the login module depending on which page (menu item) the user is currently on. Some modules are linked to components: the “latest news” module, for example, links to the content component (com_content) and displays links to the newest content items. However, modules do not need to be linked to components; they don't even need to be linked to anything and can be just static HTML or text.
Modules are managed in the Joomla! Administrator view by the Module Manager. More information about module management can be found on the appropriate version help screens.
<translate> A module position is a placeholder in a template. Placeholders identify one or several positions within the template and tell the Joomla! application where to place output from modules assigned to a particular position. The template designer has complete control over module positions, creating variations between templates and the respective Joomla! default positions assigned to modules in the installation sample data.
For example, the module position Left could be defined to be on the left side of the template to display a site navigation menu. So if a module is assigned the Left position, it will be displayed wherever the designer puts that Left module position - not necessarily the left side of the page. </translate>
Module Class Suffix
<translate> Module Class Suffix is a parameter in Joomla! modules. It is set Module: [Edit] screen under Advanced Parameters. Setting this parameter causes Joomla! to either add a new CSS class or modify the existing CSS class for the
div element for this specific module.
When Joomla! generates a module, it automatically create a CSS class called "moduletable" to allow styling of the module -- for example,
To create a new class, enter the parameter with a leading space. For example, entering a space plus "myNewClass" will create a new CSS class called "myNewClass". The HTML will be changed to
<div class="moduletable myNewClass">
To change the name of the existing class, enter in the parameter without a leading space. For example, entering "_mySuffix" (no leading space) will cause the HTML to changed to
Generally, it is recommended to use a leading space to create a new class. This way, CSS styling for this module that uses the standard class names will continue to work. You can use the new class name to add any desired styling to the module without needing to re-create all of the existing CSS code. Note that, if you create a new class name, make sure it has a unique name and doesn't conflict with any existing class names.
See Using Class Suffixes for more information.</translate>
Page Class Suffix
<translate> Page Class Suffix is a parameter in Joomla! content menu items. It is set in a particular menu item: [Edit Menu Item] page, under the "Page Display" tab. A new page class suffix will cause Joomla! to either add a new CSS class or modify the existing CSS class for elements in the assigned to this very menu item page layout.
When Joomla! generates a page, it automatically creates pre-defined CSS classes to allow styling of the page. For example, a page might have the element
To create a new class, enter the parameter with a leading space. For example, entering a space plus "myNewClass" will create a new CSS class called "myNewClass" and it will be inserted as a class for elements in that Menu Item. In this case the example above will be changed to
<div class="componentheading myNewClass">
To change the name of the existing class, enter in the parameter without a leading space. For example, entering "_mySuffix" (no leading space) will cause the HTML to changed to
Generally, it is recommended to use a leading space to create a new class. This way, CSS styling for this component that uses the standard class names will continue to work. You can use the new class name to add any desired styling to the component without needing to re-create all of the existing CSS code. Note that, if you create a new class name, make sure it has a unique name and doesn't conflict with any existing class names.
<translate> The term patch file is used for two different file types. The term patch file is sometimes used to refer to archive files that allow you to upgrade from one Joomla! version to another (for example, from version 1.0.0 to version 1.0.7). These upgrade files are also referred to as upgrade packages.
The other meaning for a patch file is a file created by source code version control software -- for example, Subversion or SVN, which is used for the Joomla! source code. This type of patch file contains instructions for changing the contents of one or more source code files. The SVN software reads the patch file and then can automatically change the source code of the files being patched.
Patch files are used by the Bug Squad to test proposed bug fixes. They can also be used to contribute proposed new features to the version under development. For more information about the structure of SVN patch files, read Learn more about patch files.
<translate> PHP is a computer scripting language designed for creating dynamic web pages. PHP is widely-used for web development and can be embedded into HTML. It generally runs on a web server, taking PHP code as its input and creating web pages as output. Joomla! is primarily written using the PHP language. For more information, see Where can you learn about PHP? </translate>
<translate> A plugin is a kind of Joomla! extension. Plugins provide functions which are associated with trigger events. Joomla provides a set of core plugin events, but any extension can fire (custom) events. When a particular event occurs, all plugin functions of the type associated with the event are executed in sequence. This is a powerful way of extending the functionality of the Joomla! Platform. It also offers extension developers a way to allow other extensions to respond to their actions, making extensions extensible.</translate>
<translate> The Joomla! plugin architecture follows the Observer design pattern. The JPlugin class provides the means to register custom plugin code with core or custom events. The JDispatcher class (JEventDispatcher in Joomla 3.x) is an event handler which calls all plugins registered for a particular event, when that event is triggered.</translate>
In Joomla! versions up to and including , a Section is a collection of Categories. It is the top level in the hierarchy Sections -> Categories -> Articles. For example, a website might have Sections called "Animals" and "Plants". Within the "Animals" Section, the website might have Categories such as "Birds" and "Mammals".
- REDIRECT Chunk:SEF URLs
<translate> A split menu is where different levels of a single menu are displayed in two or more locations on a single web page.
For example, a common requirement is for a menu of top-level items to appear at the top of the page. When one of the items is clicked the user is taken to a page where a secondary menu, say on the left of the page, shows second-level items within the scope of the top-level item.
The menus appear in separate locations on the page, but are related because one shows only top-level items while the other shows second-level items. This idea can be extended to include menus for third-level items and beyond.
This can be implemented in Joomla using a single multi-level menu then creating more than one menu module each referring to a different level.
See also: Menu</translate>
<translate> An Upgrade Package in Joomla! is an archive of files that contain the files that have changed between Joomla! versions. When this archive is unpacked, it replaces the old version of the modified files with the new version. For example, if fifty files were changed between version 3.x.1 and 3.x.2, the upgrade package from 3.x.1 to 3.x.2 would contain these fifty files and, when unpacked, would replace these fifty files and upgrade the installed version from 3.x.1 to 3.x.2.