Intro to Joomla Development

SourceCoast Extensions sourcecoast.com Intro To Joomla Development

Joomla Development

I t ’ s E a s i e r T h a n Y o u T h i n k

1Saturday, August 6, 11


SourceCoastA l e x A n d r e a e

O w n e r / D e v e l o p e r

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Overview

Module Structure

API Overview

Component Structure



Joomla - MVC

MVC(t) – Model View Controller (template)

Controller – Sets up environment for the display

Model – Data interface

Generally to the database, but can 'create' data if necessary

View – Uses the model to get data to display

Template – Override-able display output



ModulesLinear code execution

VC(t) (no real model necessary)

Uses a 'helper.php' file for additional function calls

Can be model-like, but modules don’t have DB tables

Files:

mod_<modulename>.php and .xml

helpers/helper.php

tmpl/default.php



Modules - Basics

mod_demo.php

default.php

mod_demo.xml



Module Helper Filesmod_demo.php

helper.php

default.php

* Separate out Classes/Functions



Modules/Component Interactionmod_demo.php

helper.php

default.php

* Load Component’s model* Re-Use Code!



Joomla API Overview



Joomla APIhttp://api.joomla.com

Recently updated to Joomla 1.7 API - YAY!

Left side, select “Joomla-Platform” package

Bookmark, cuddle up to, and learn to love this page

“Classes” describes

JFactory – Most widely used

JRoute – Get URL for specific component/view/task

“Application” describes

Every other Joomla function (many inherited into JFactory)


http://api.joomla.com

http://api.joomla.com


JObject

All Joomla classes derived from (You should too)

Easy getter/setter methods

$obj->set(‘var’, ‘value’); // Set a variable

$obj->get(‘var’, ‘default’); // Get a value

$obj->def(‘var’, ‘default’); // Set a default

$obj->toString(); // Great for debugging (no print_r($obj) required!



JUser Object$user = JFactory::getUser(); // logged in user

$user = JUser::getInstance($id);

$id = UID or username

Once fetched, use

if ($user->guest)

$user->get('username'); // id, fullname, lastvisitDate, etc

It’s derived from JObject!



JFactory - Database$dbo =& JFactory::getDBO() // Get the database handle

Functions described in JDatabase & JDatabaseMySQL(i)

$query = $dbo->getQuery(true); // New Query$query->select(“id, username, email”);$query->from(“#__users”);$query->where(“username=”.$dbo->quote($username); // No shenanigans!$dbo->setQuery($query);

$dbo->setQuery(“SELECT id,username,email FROM #__users WHERE username = “.$dbo->quote($username)); // Not as flexible

$user = $dbo->loadObject(); // objectList, array, arrayList, result, etc

Can use InsertObject function (or raw SQL) to add rows to database



URL RoutingJRoute

JRoute::_('index.php?option=com_content&view=article&id=12');

Will determine correct SEF URL, if SEF is enabled

Also, SEF components (sh404, Artio, etc) override this call, so it works for them too!

JURI

$uri = JFactory::getURI(); // Get current query string

$uri->setVar('view', 'blah'); // Add/change value

JRoute::_('index.php?'.$uri->getQuery()); // Create new route



JApplicationHandle to the Application class

$app =& JFactory::getApplication();

$app->enqueueMessage('blah', 'error');

$app->redirect($url); // Use JRoute!

$app->isAdmin()

$app->isSite()

Formerly global $mainframe. Globals are bad..



JTextText translation from language files

JText::_('COM_JFBCONNECT_LOGIN_MESSAGE’);

Searches loaded language files in last loaded order

Searches for first, exact, upper case version

If found, use translation; If not, use text directly

To include more language files:

$lang = JFactory::getLanguage(); // Get language object

$lang->load('com_jfbconnect'); // Add your file



JRequest

JRequest::getVar('name', 'default', 'POST');

Can be risky depending on use. Preferred to use the below 'sanitized' methods

JRequest::getInt('name', 4); // Integers only, default 4

JRequest::getCmd('task'); // strip \./

JRequest::getString('name'); // No nasty HTML



JFilterInput

Clean data before using in code

Used to prevent SQL, XSS, and other shenanigans or exploits

$filter =& JFilterInput::getInstance();

$filter->clean($var, ‘string’); //int, etc

Similar to (and used by) JRequest, but can be used on any data, not just environment variables



Jsession

Store information volatile information for user

Form information on validation failure

Information before a redirection (to login, etc)

$session = JSession::getInstance();

$session->set('city', $cityInput); // Set now

$city = $session->get('city', ''); // Get later

$session->clear('city');



Component Structure



Component Structure

True MVC(t) structure

<component_name>.php – entry-point. Determines controller and calls task on it

controller.php – Sets up the model(s) and other data structures to be used

/models/<model>.php – Data interface

/viewname/view.html.php – Uses the models to fetch and setup the data for the template

/viewname/tmpl/default.php (or any other template file)



Component Entry Point

* /components/com_blah/blah.php* Purpose: setup your component - defines, includes, etc* Initialize the right controller for the page* Start executing whatever is requested* (This) code expects query string “task” param to be set* If execute called with no param, “display” will be default



Component Controllers

Fetch model(s) for data manipulation/checks* $model = $this->getModel('mymodel')* Verify something from the model to proceed or cause a redirect* Ex. Load article, check if published, if not, redirect

Instantiate the View* $view = $this->getView(‘viewName’, ‘html’);* Hand any data (model) to it for use * $view->setModel($model); * $view->assignRef(‘var’, $data); // var for the template* Tell the View to do it’s thing * $view->setLayout(‘templateName’); * $view->display();



Controller(Fake) Content Example

Get article

Check if published

Load the view and prepare the template

By default, view of same name as controller will be called

Otherwise, use $view code from previous slide



Component Model

The model is your database interface

Extends JModel

Has SQL queries for read or write

Model allows you to retrieve and manipulate data simulating higher level database functions

Table class available for row-based read/writes

$this->_db is pre-set as database object



Fetch the data needed from Model

Set data for template file

$this->assignRef('varName', $var);

Call the template to load

Component View



Component Template

Little/no code other than echo's

Should use only variables set from View

<?php echo $this->varName ?>

If followed, template overrides become simple

If not, life becomes a nightmare for your clients



PluginsJDocument

JLogJFormOh My!


Technology

Intro to Joomla Development