PHP essentials - Revision history

Hutchy68: removing needs review

2013-04-26T00:23:44Z

removing needs review

Hutchy68: updates, no really sure why docs is teaching php

2013-04-26T00:22:10Z

updates, no really sure why docs is teaching php

Timj: /* PHP Round-trip */

2012-01-03T23:05:56Z

‎PHP Round-trip

Mvangeest: Made miscellaneous improvements

2011-11-27T12:56:29Z

Made miscellaneous improvements

Mjd111: /* Defining Array Structures */

2011-04-09T19:35:46Z

‎Defining Array Structures

Mjd111: /* Control Expressions */

2011-04-09T19:33:31Z

‎Control Expressions

Chris Davenport: Corrected PHP syntax

2010-09-25T06:37:29Z

Corrected PHP syntax

Airforcebrat747: /* Handling Forms */

2010-09-24T20:57:21Z

‎Handling Forms

Airforcebrat747: /* Defining Functions */

2010-09-24T20:55:41Z

‎Defining Functions

Airforcebrat747: /* Defining Array Structures */

2010-09-24T20:54:04Z

‎Defining Array Structures

@@ Line 1: / Line 1: @@
-{{review}}
+Many web designers and casual website owners are not conversant with the PHP language in which Joomla! is written and since Joomla! templates usually contain PHP statements it is necessary to understand at least a little of the language in order to be able to create or customize templates. This chunk will describe, in simple terms, how to use each aspect of PHP in the context of a Joomla! template. For example, a simple explanation of the PHP if-then-else syntax using extracts from a template for illustration.
 Many web designers and casual website owners are not conversant with the
 PHP language in which Joomla! is written and since Joomla! templates
 usually contain PHP statements it is necessary to understand at least a
 little of the language in order to be able to create or customize
 templates. This chunk will describe, in simple terms, how to use each aspect of PHP in the
 context of a Joomla! template. For example, a simple explanation of the PHP
 if-then-else syntax using extracts from a template for illustration.
 The best resource to learn PHP is probably hands on experience and Joomla can provide that to you thanks to it's native PHP code.  This can be overwhelming for people who have not programmed before. Though Joomla is easy enough to [[Installation|install]] with the help of the community and a little of your time you'll have people asking you to do their websites.

@@ Line 12: / Line 12: @@
 One place that has a nice short list if functions and examples is http://en.wikiversity.org/wiki/25_Essential_PHP_Functions which is good to get familiar with PHP. Though for an extensive function list, explanations, and examples go to http://www.php.net.
-Once you have the basics of PHP you'll need to get the basics of the Joomla PHP syntax.  Start by looking at some existing {{jsite|ext|extensions}} and check out the code and also take a look at some these Tutorials about Joomla:
+Once you have the basics of PHP you'll need to get the basics of the Joomla PHP syntax.  Start by looking at some existing [http://extensions.joomla.org extensions] and check out the code and also take a look at some these Tutorials about Joomla:
 * [[Developing a Model-View-Controller Component - Part 1]]
@@ Line 44: / Line 44: @@
 </source>
-Save this file, point your browser to http://localhost/x/y/first.php, and you should be able to see the echo message.
+Save this file, point your browser to '''<nowiki>http://localhost/x/y/first.php</nowiki>''', and you should be able to see the echo message.
 The primary things to note here are: <pre>

@@ Line 38: / Line 38: @@
 <body>
 <?php
-echo ("My first php snippet");
+echo "My first php snippet";
 ?>
 </body>

@@ Line 14: / Line 14: @@
 Once you have the basics of PHP you'll need to get the basics of the Joomla PHP syntax.  Start by looking at some existing {{jsite|ext|extensions}} and check out the code and also take a look at some these Tutorials about Joomla:
-[http://developer.joomla.org/tutorials/184-how-to-create-a-joomla-plugin.html How to create a Joomla! Plugin]
+* [[Developing a Model-View-Controller Component - Part 1]]
+* [[Creating a Plugin for Joomla 1.5]]
-[http://docs.joomla.org/Developing_a_Model-View-Controller_Component_-_Part_1 Developing a Model-View-Controller Component - Part 1]
+* [[Creating a simple module]]
-−
-[http://docs.joomla.org/Developing_a_Model-View-Controller_Component_-_Part_2_-_Adding_a_Model Developing a Model-View-Controller Component - Part 2 - Adding a Model]
-−
-[http://docs.joomla.org/Developing_a_Model-View-Controller_Component_-_Part_3_-_Using_the_Database Developing a Model-View-Controller Component - Part 3 - Using the Database]
-−
-[http://docs.joomla.org/Developing_a_Model-View-Controller_Component_-_Part_4_-_Creating_an_Administrator_Interface Developing a Model-View-Controller Component - Part 4 - Creating an Administrator Interface]
 That will help you get familiar with some of the functions available within Joomla's system and what they do (using the API).  Take particular care to understand the MVC (model view control) setup.
@@ Line 100: / Line 94: @@
 '''Ways of declaring arrays'''
 <br> Suppose we want many variables. We could have declared the variables as shown above; however, that is not elegant. Suppose you want 100 variables; declaring arrays come to the rescue. Note that the index in PHP starts with 0.
-<pre>
+<source lang="php">
 $my_guitar_heroes = array ("Hendrix", "Shankar", "Gilmour", "to_name_a_few!");
-</pre>
+</source>
 Or
-<pre>
+<source lang="php">
 $my_guitar_heroes [] = "Hendrix";
 $my_guitar_heroes [] = "Shankar";
 $my_guitar_heroes [] = "Gilmour";
 $my_guitar_heroes [] = "to_name_a_few!";
-</pre>
+</source>
 Here PHP automatically assigns the index.
 Or
-<pre>
+<source lang="php">
 $my_guitar_heroes [0] = "Hendrix";
 $my_guitar_heroes [10000] = "Mainak";
-</pre>
+</source>
 Here, I knew the first and the 10,001st element but that's me!
@@ Line 123: / Line 117: @@
 Or
-<pre>
+<source lang="php">
 // Set the elements at positions 1 through 9999 to the value, "to be decided".
 $my_guitar_heroes  = array_fill( 1, 9999, "to be decided" );
-</pre>
+</source>
 '''Accessing the Arrays'''
-<pre>
+<source lang="php">
 print $my_guitar_heroes[2]; //Access the 3rd element
-</pre>
+</source>
 Or
-<pre>
+<source lang="php">
 // Access the last element (Note that the element positions are numbered zero to
 // [number of elements] minus one.)
 $my_guitar_heroes[count($my_guitar_heroes)-1];
-</pre>
+</source>
 Or
-<pre>
+<source lang="php">
 // Access the last element using a function call.
 end($my_guitar_heroes);
-</pre>
+</source>
 '''Iterating Over the Element of an Array'''
-<pre>
+<source lang="php">
 foreach ( $my_guitar_heroes as $temp) {
    print "$temp<br />";
+}
-</pre>
+</source>
 ==== Control Expressions ====
@@ Line 214: / Line 208: @@
 A basic way to debug is to print the value of the variable. The following basic statements achieve that:
-<ul>
+* <code>echo "if double quotes are used then dollar variables are resolved";</code>
-<li>echo "if double quotes are used then dollar variables are resolved";
+* <code>echo 'if single quote are used then dollar variables are not resolved';</code>
-<li>echo 'if single quote are used then dollar variables are not resolved';
+* <code>print "another way to print";</code>
-<li>print "another way to print";
+* <code>nl2br("any new line characters like \n get automatically resolved to HTML line breaks");</code>
-<li>nl2br("any new line characters like \n get automatically resolved to HTML line breaks");
-</ul>
 Apart from these, the log files are very helpful and can be found in the WAMP_HOME/logs directory.
 ==== Handling Forms ====
 PHP does not change any HTML structure, thus any syntax of HTML remains the same. The part that PHP plays is making any part dynamic for e.g., the action attribute of a form can be coded as action=<?php my_own_action(); ?> so that it is dynamically generated. The part where PHP kicks in is after the form is submitted, say to obtain the values of the form fields, set cookies, etc. For this, super global variables are used, which are always available to PHP code. Some of these are:
-<ol>
-<li>$_GET - get the data from a GET request</li>
+# <code>$_GET</code> - get the data from a GET request
-<li>$_POST - get the data from a POST request</li>
+# <code>$_POST</code> - get the data from a POST request
-<li>$_REQUEST - get the request</li>
+# <code>$_REQUEST</code> - get the request
-<li>$_COOKIE - obtain the cookies from the browser</li>
+# <code>$_COOKIE</code> - obtain the cookies from the browser
-<li>$_SESSION - obtain the session</li>
+# <code>$_SESSION</code> - obtain the session
-</ol>
 These are all arrays, and behave accordingly.
+<noinclude>[[Category:Development]][[Category:Tutorials]]</noinclude>
-----
-[[Category:Templates]]

@@ Line 130: / Line 130: @@
 '''Accessing the Arrays'''
 <pre>
-print $my_guitar_heroes[2]; //Access the 2nd element
+print $my_guitar_heroes[2]; //Access the 3rd element
 </pre>
 Or

@@ Line 177: / Line 177: @@
 while ( $x <= 10 ) {
   print "$x<BR/>";
+}
 </source>

@@ Line 190: / Line 190: @@
 ==== Defining Functions ====
-Code which is duplicated in many places are best placed in a function. The following are the ways of describing the function:
+Code which is duplicated in many places is best placed in a function. The following are the ways of describing the function:
 <source lang="php">
 function name_of_the_function( $arguments, $size='default_values_if_any' ) {
@@ Line 197: / Line 197: @@
+}
 </source>
-The arguments are passed by value. If they are to be passed by reference, then an argument is prefixed by "&" as below
+The arguments are passed by value. If they are to be passed by reference, then an argument is prefixed by "&" as below:
 <source lang="php">
 function name_of_the_function( &$arguments, $size='default_values_if_any' ) {