Whether you are developping a plugin, or want to correct a bug, or simply add a functionality, following these few rules is necessary.

All of Dotclear's code must function with the following PHP configuration:

• short_open_tag = Off
• allow_call_time_pass_reference = Off
• error_reporting = E_ALL | E_STRICT
• display_error = On
• register_globals = Off
• magic_quotes_gpc = Off
• allow_url_fopen = Off

Code should work with PHP 5.0 at a minimum.

ini_set('display_errors',true);
error_reporting(E_ALL | E_STRICT);

Use an indentation in real tabulations (not in spaces). The usual (and practical) width of a tabulation is of 5 spaces in Dotclear's code.

Lines should not exceed 70 characters in length.

The control structures are the if, switch, for, while, foreach, etc. instructions. You must leave a space between the instruction's keyword and the condition. The bracket's position is up to you.

<?php
if (condition1 && condition1) {
     action;
}
 
foreach ($tableau as $k => $v)
{
     action;
     action;
}
?>

The functions are called without any space between the name of the funtion, the parenthesis and the parameters. For example: Les fonctions sont appelées sans aucun espace entre le nom de la fonction, les parenthèses

<?php
maFonction($var1,$var2);
?>

If the function is returned in a variable, at least one space should be used on either side of the equal sign. For example:

<?php
$var = maFonction($var1);
?>

The function's brackets are placed under its name and the code is indented (one level). For example:

<?php
maFonction($var1,$var2=0)
{
     return $var1+$var2;
}
?>

Comments on a line are often made with the # sign, less with the //. Comments for several lines are made with the /* comment */ style.

Deactivating a portion of the code with a comment will be done with /* //*/. In this manner it takes only a / to deactivate the comment. For example:

<?php
/*
code();
//*/
?>

A file is included in another relatively to the first one. This is mandatory. For example:

<?php
require dirname(__FILE__).'/../../fichier.php';
?>

PHP code is always delimited with <?php ?> and not with the abbreviated version <? ?>. This is mandatory. The form <?= ?> is of course proscribed.

Classes are always names with unaccentuated characters. Words are separated with uppercase letters and the name of the class starts with a lowercase. For example:

<?php
class myClass
{
//...
}
?>

Functions' names follow the same rules as those of classes.

The name of the variables must have a meaning. The words are separated by underscores (_). For example:

<?php
$my_variable = 'text';
$var = 'text...';
?>

Dotclear tries to comply as much as possible to HTTP, which implies a certain number of rules.

All data change (in the database or elsewhere) must happen through a HTTP POST request.

More over, all requests of this type must send a field names "xd_nonce" containing an identifier allowing to check its legitimity.

It is therefore necessary to send this field to all forms of the type POST. For example:

<form action="foo.php" method="post">
<p>....</p>
<p><?php echo $core->formNonce(); ?></p>
</form>

Calling the $core→formNonce() method automatically inserts a hidden field containing the value of nonce in the form.

Finally, what is valid for form submissions is also valid for requests made via XML HTTP Request (Ajax) of the POST type. Dotclear provides a javascript variable containing the nonce: dotclear.nonce.

Example of an ajax request with nonce:

params = {
  xd_check: dotclear.nonce,
  p: "param"
};
 
$.post(url,params,function() {
	...
});

Make sure the XHTML code of your theme or plugin is valid. It is possible to check the validity of the XHTML even if it is not accessible (for example in the administration) thanks to the Web Developer extension for Mozilla Firefox.

In order for a plugin or a theme which accesses the database to function properly on all blogs, it must be tested with MySQL and PostgreSQL (PGSQL). If you can't make the tests with one of those database types, ask for help on the Dotclear forum .