=========================================================================== || PEAR Coding Standards || =========================================================================== $Id$ ------------- [1] Indenting ============= Use an indent of 4 spaces, with no tabs. If you use Emacs to edit PEAR code, you should set indent-tabs-mode to nil. Here is an example mode hook that will set up Emacs according to these guidelines (you will need to ensure that it is called when you are editing php files): (defun php-mode-hook () (setq tab-width 4 c-basic-offset 4 c-hanging-comment-ender-p nil indent-tabs-mode (not (and (string-match "/\\(PEAR\\|pear\\)/" (buffer-file-name)) (string-match "\.php$" (buffer-file-name)))))) Here are vim rules for the same thing: set expandtab set shiftwidth=4 set tabstop=4 ---------------------- [2] Control Structures ====================== These include if, for, while, switch, etc. Here is an example if statement, since it is the most complicated of them: if ((condition1) || (condition2)) { action1; } elseif ((condition3) && (condition4)) { action2; } else { defaultaction; } Control statements should have one space between the control keyword and opening parenthesis, to distinguish them from function calls. You are strongly encouraged to always use curly braces even in situations where they are technically optional. Having them increases readability and decreases the likelihood of logic errors being introduced when new lines are added. For switch statements: switch (condition) { case 1: action1; break; case 2: action2; break; default: defaultaction; break; } ------------------ [3] Function Calls ================== Functions should be called with no spaces between the function name, the opening parenthesis, and the first parameter; spaces between commas and each parameter, and no space between the last parameter, the closing parenthesis, and the semicolon. Here's an example: $var = foo($bar, $baz, $quux); As displayed above, there should be one space on either side of an equals sign used to assign the return value of a function to a variable. In the case of a block of related assignments, more space may be inserted to promote readability: $short = foo($bar); $long_variable = foo($baz); ------------------------ [4] Function Definitions ======================== Function declaractions follow the "one true brace" convention: function fooFunction($arg1, $arg2 = '') { if (condition) { statement; } return $val; } Arguments with default values go at the end of the argument list. Always attempt to return a meaningful value from a function if one is appropriate. Here is a slightly longer example: function connect(&$dsn, $persistent = false) { if (is_array($dsn)) { $dsninfo = &$dsn; } else { $dsninfo = DB::parseDSN($dsn); } if (!$dsninfo || !$dsninfo['phptype']) { return $this->raiseError(); } return true; } ------------ [5] Comments ============ Inline documentation for classes should follow the PHPDoc convention, similar to Javadoc. More information about PHPDoc can be found here: http://www.phpdoc.de/ Non-documentation comments are strongly encouraged. A general rule of thumb is that if you look at a section of code and think "Wow, I don't want to try and describe that", you need to comment it before you forget how it works. C++ style comments (/* */) and standard C comments (// ) are both fine. Use of perl/shell style comments (# ) is discouraged. ------------------ [6] Including Code ================== Anywhere you are unconditionally including a class file, use require_once. Anywhere you are conditionally including a class file (for example, factory methods), use include_once. Either of these will ensure that class files are included only once. They share the same file list, so you don't need to worry about mixing them - a file included with require_once will not be included again by include_once. Note: include_once and require_once are statements, not functions. You don't need parentheses around the filename to be included. ----------------- [7] PHP Code Tags ================= ALWAYS use to delimit PHP code, not the shorthand. This is required for PEAR compliance and is also the most portable way to include PHP code on differing operating systems and setups. ------------------------- [8] Header Comment Blocks ========================= All source code files in the core PEAR distribution should contain the following comment block as the header: /* vim: set expandtab tabstop=4 shiftwidth=4: */ // +----------------------------------------------------------------------+ // | PHP version 4.0 | // +----------------------------------------------------------------------+ // | Copyright (c) 1997, 1998, 1999, 2000, 2001 The PHP Group | // +----------------------------------------------------------------------+ // | This source file is subject to version 2.0 of the PHP license, | // | that is bundled with this package in the file LICENSE, and is | // | available at through the world-wide-web at | // | http://www.php.net/license/2_02.txt. | // | If you did not receive a copy of the PHP license and are unable to | // | obtain it through the world-wide-web, please send a note to | // | license@php.net so we can mail you a copy immediately. | // +----------------------------------------------------------------------+ // | Authors: Original Author | // | Your Name | // +----------------------------------------------------------------------+ // // $Id$ There's no hard rule to determine when a new code contributer should be added to the list of authors for a given source file. In general, their changes should fall into the "substantial" category (meaning somewhere around 10% to 20% of code changes). Exceptions could be made for rewriting functions or contributing new logic. Simple code reorganization or bug fixes would not justify the addition of a new individual to the list of authors. Files not in the core PEAR repository should have a similar block stating the copyright, the license, and the authors. All files should include the modeline comments to encourage consistency. ------------ [9] CVS Tags ============ Include the Id CVS vendor tag in each file. As each file is edited, add this tag if it's not yet present (or replace existing forms such as "Last Modified:", etc.). [NOTE: we have a custom $Horde tag in Horde cvs to track our versions seperately; we could do the same and make a $PEAR tag, that would remain even if PEAR files were put into another source control system, etc...] ----------------- [10] Example URLs ================= Use "example.com" for all example URLs, per RFC 2606. --------------------- [11] Naming Constants ===================== Constants should always be uppercase, with underscores to seperate words. Prefix constant names with the name of the class/package they are used in. For example, the constants used by the DB:: package all begin with "DB_". True and false are built in to the php language and behave like constants, but should be written in lowercase to distinguish them from user-defined constants.