Extension Development

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You find all the different extension development manuals either by the extensions themself or in the TYPO3 documentation matrix.

Contents 1 Development Mini-HOWTO 1.1 External resources 1.2 Documentation 1.3 Debug TYPO3 1.3.1 debug TypoScript 1.4 Get the source code 1.5 Classes and functions 1.6 Flexforms 1.7 Multiple Languages 1.8 Unix 1.9 Database 1.10 Variables 1.11 Use libraries and APIs 1.12 Caching issues 1.13 Blocking errors 1.14 HTML output into a file 1.15 Standards 1.16 Send patches 1.17 Help

Development Mini-HOWTO

This is a small HowTo showing you how to start developing for TYPO3.

External resources

• Use the PHP Manual.
• Download a PHP development environment
  • Eclipse IDE
  • PHP IDE Project
  • PHP Eclipse
  • Clay Database Modeling
• Use a tool like fabFORCE DBDesigner4 to draw your database tables and the relationships among them.

Documentation

• Read the TYPO3 API Documentation.
• Install the Extension Development Evaluator (extdeveval) (contact: kasper) extension. It gives you the APIs for extensions and a link list to documentation:
  

• Search in the Namazu: Full-Text Search Engine.
• Follow the Project Coding Guidelines
• Read the Extension Developers Guide
• Extension Development Guide (XDG)
• Extension Development, using Flexforms
• Backend Programming
• Translate and document yor extension following the TYPO3.org - manual for developers (How typo3.org works)
• Use the Documentation template for yor extension documentation Documentation template

Debug TYPO3

See also the XDG

• Enable [FE][debug] = 1 and set the [SYS][devIPmask] (e.g. = 192.*,169.*,127.0.0.1). Then use the extended debug() function of the Extension cc_debug. On your TYPO3 homepage you will get a bomb

in the upper right corner if there is a debug information in the currently running PHP script.

<PHP> :

 
# gives you the output of the variable together with the line number and file name.
 
debug ($variable, 'Output of variable', __LINE__, __FILE__); 
 

<PHP> :

 
# Gives you the list of functions and files from where it has been called.
$tmp = t3lib_div::debug_trail();
debug ($tmp, 'calling path in className::methodName', __LINE__, __FILE__);
 

<PHP> :

 
 # If you want to implement the devLog in your applications: 
 t3lib_div::devLog 
 
 #simply add lines like:
 if (TYPO3_DLOG) t3lib_div::devLog('[write message in english here]', 'extension key');
 

The cc_devlog - extension provides development logging/debugging functionality for the usage of t3lib_div::devlog(). The t3lib_div::devlog() function itself provides only an interface for logging but no implementation.
rlmp_filedevlog logs messages from t3lib_div::devlog() calls into a text file, by default to debug.log of your apache home directory, e.g. at /var/www/html/.
Do not forget to give it write access for the apache httpd user.

You have to activate devLog by putting this line into your typo3conf/localconf.php file. <PHP> :

 
$TYPO3_CONF_VARS["SYS"]["enable_DLOG"] = '1';
 

<PHP> :

 
 # debug SQL
 $GLOBALS['TYPO3_DB']->store_lastBuiltQuery = TRUE;
 $GLOBALS['TYPO3_DB']->exec_UPDATEquery( 'xxx', 'yyy', 'zzz');
 t3lib_div::devLog('[write message in english here]'.$GLOBALS['TYPO3_DB']->debug_lastBuiltQuery; , 'extension key'); 
 

use the

<PHP> :

 
 error_log('text',0)
 error_log('postition A: $content='.$content , 3, '/usr/local/htdocs/typo3/error_log');
 

and view the entries of the log file. (Linux: /var/log/messages, /var/log/apache2/error_log or /var/log/httpd/error_log). Or modify the 'error_log = syslog' settings in /etc/php.ini .
If you use error_log with a third parameter then this will be the error_log file for this case only.

To show the contents of arrays you use foreach loops: <PHP> :

 
 
 foreach ($menuItems as $key=>$menuItem) {
 	if (is_array($menuItem)) {
 		error_log ('-- tx_commerce_cm1 menuItem['. $key . '] --', 0);
 		foreach ($menuItem as $k1=>$v1) {
 			error_log ('['.$k1.']='.$v1,0);
 		}
 	} else
 	{
 		error_log ('-- tx_commerce_cm1 menuItem['. $key . '] = '.$menuItem, 0);
 	}
 }
 
 
# Or use these lines with var_dump:
 ob_start();
 var_dump($myComplexArray);
 $debugOut = ob_get_contents();
 ob_end_clean();
 error_log ('$myComplexArray = '.$debugOut);
 

debug TypoScript

see TSref section stdWrap

At the end of the table you will see three stdWrap options which let you enter in debug mode :

• debug boolean

Prints content with HTMLSpecialChars() and

???

: Usefull for debugging which value stdWrap actually ends up with, if you're constructing a website with TypoScript.

Should be used under construction only.

• debugFunc boolean

Prints the content directly to browser with the debug() function. Should be used under construction only. Set to value "2" the content will be printed in a table - looks nicer.

• debugData boolean

Prints the current data-array, $cObj->data, directly to browser. This is where ".field" gets data from. Should be used under construction only.

IMHO in order to not affect other pages, simply build a +ext template for the specific page you want to debug so that you can manipulate you typoscript code as you want. Once it's tuned, delete the +ext template.

Get the source code

• You can get the latest source code of TYPO3 extensions from TYPO3 Extension Development Platform and TYPO3 itself from the TYPO3 Content Management Framework.
• You can browse the source code for extensions at http://typo3xdev.svn.sourceforge.net/viewvc/typo3xdev/ the TYPO3 Core at http://typo3.svn.sourceforge.net/viewvc/typo3/TYPO3core/ or both at http://svn.t3.digitaldistrict.de/cgi-bin/trac.cgi/browser .
• If you want to download everything in a ZIP file have a look at the most recent downloads for developers.

Classes and functions

• global $TSFE (or $GLOBALS["TSFE"]), the main front end class, can be found in tslib\class.tslib_fe.php
• Use parseFunc to convert text from input to disallow HTML tags or allow only those the from the allowTags setting. See parseFunc
  

if (is_array($this->conf["parseFunc."]))	{
$markerArray["###PRODUCT_NOTE###"] = 
$this->cObj->parseFunc($markerArray["###PRODUCT_NOTE###"],$this->conf["parseFunc."]); 
}

Flexforms

• If you wish to use flexforms in your extension, follow the Using Flexforms guide.

Multiple Languages

• Create XML language files to support multiple languages. Use the locallang-XML translation tool to convert php language files into XML and do some cleanings.
• Create overlay tables which contain only the fields which need translations. Use the Table Library to create SQL queries which hides the language overlay tables to the developer.

Unix

• Use this command line to search for a pattern in many files under Linux

cd directory-of-sources
find . -name '*.php' -exec grep -ni 'your search string' {} \; -ls

• Or, "man grep" and see if your installed grep can do something like:

grep -rniH --include '*php' 'your search string' directory-of-sources

• Use the Linux cheat sheet for a short description of Linux commands

Database

• Database Abstraction Layer - DBAL

To activate the writing of error messages when one of your database accesses fails, open the file typo3/t3lib/class.t3lib_db.php and change the line

// Debug:
var $debugOutput = FALSE;		// Set "TRUE" if you want database errors outputted.

to

// Debug:
var $debugOutput = TRUE;

To get detailed infos about the created SQL command you make an error_log entry into the function, e.g. SELECTquery.
The following change will write all the created database statements into the error_log file:

function debug($func)	{
error_log ($this->debug_lastBuiltQuery, 0);

In the Install Tool 'All Configuration' set

[SYS][sqlDebug] = 1 // Boolean. If set, then database queries that fails are outputted in browser. For development.

Or in typo3conf/localconf.php or somewhere in the code of your extension:

$TYPO3_CONF_VARS['SYS']['sqlDebug'] = 1;

Variables

• access the global variables, e.g.

global $BE_USER, $LANG, $BACK_PATH, $TYPO3_CONF_VARS, $HTTP_GET_VARS, $HTTP_POST_VARS;

Use libraries and APIs

please add the ones you like. --Daniel Brüßler 11:03, 4 June 2007 (CEST)

• meta_feedit (meta_feedit) (contact: cbalisky)
• Date selector library (rlmp_dateselectlib) (contact: multani)
  date selector, calendar javascript
• rgfolderselector (rgfolderselector) (contact: just2b)
  folder selector field for the backend
• div (div) (contact: elmar.hinz)
  Static methods for extensions. It has copies of itself as div<year> for each year in order to allow many versions of it at a time.

Caching issues

• read how to manage the cache - Caching and The Mysteries Of &cHash
• How to avoid the no_cache parameter? Proper Caching

• Generally you have to use the extension variable like 'tx_myext_pi_name[variable]'.
• You can also define standalone parameters e.g. for 'begin_at', 'offset' and similars for which the cHash parameter will get created using these functions:

tslib_pibase::pi_getPageLink
t3lib_div::cHashParams
tslib_fe::makeCacheHash

Blocking errors

• If due to your coding TYPO3 stops working, just view the entries of the log file. (Linux: /var/log/messages or /var/log/httpd/error_log) and search for the string 'PHP Fatal error'.

HTML output into a file

To debug errors it would be usefull to let TYPO3 save the HTML output also into a file. Modify the printContent output function to save each page into the file typo3.log.

typo3/alt_main.php:

/**
* Outputting the accumulated content to screen and into a file
*
* @return	void
*/
function printContent()	{
 echo $this->content;
 $handle = fopen(t3lib_div::getIndpEnv('TYPO3_DOCUMENT_ROOT').'/typo3conf/','wb');
 fwrite ($handle, $this->content);
 fclose($handle);
}

Standards

Take care of standards to make all TYPO3 extensions look very similar. This helps that others can easier understand your extensions and find the files in it. Standardization. These are the current recommendations. And you are invited to make your own proposals. All things which are needed in several extensions should be defined by the same namings. So the setup for one extensions could be used 1:1 for another extension as well.

Send patches

• Get your patches into TYPO3 or an extension
• Email template for Core developers

Help

• Developer list
• Forum TYPO3.NET