Best Practices For Drupal Developers By Mir Nazim @ Drupal Camp India 2008

HELLO, I AM...

Mir Nazim

Chief Architect @ iKraft Sofrware Pvt Ltd

Working on PHP/Drupal & Python/Django

since past few years

email me - [email_address]

More at www.ikraftsoft.com

BEST PRACTICES FOR DRUPAL DEVELOPERS DrupalCamp India August 8/9/10, 2008 Dhirubhai Ambani Institute of Information & Communication Technology Gandhinagar, IN

We shall be covering -Best practices for - development environment - module development - theme development - some other stuff

Get the source Start out with the CVS checkout ALWAYS ” CVS chekout instruction are available on http://drupal.org/handbooks ”

Why use CVS version

Single most important reason

EASY UPDATES

$ cvs update -dP

TO NEW DRUPAL VERSION

$ cvs update -r DRUPAL-6-3 -dP

Be sure that contibuted modules have been ported to the

new version

revision control your project -Even if: - it is a small project - only you are working on it - Take a pick - svn, bzr, git, darcs ... - VSS(if you are crazy enough) - BUT NOT CVS('coz drupal uses it) the benifits are way too many!

The Editor Wars - Komodo Edit/IDE my favourite - Scribes on GNOME my other favourite - PHPEclipse or Eclipse PDT - Qunta Plus on KDE - TextMate on Mac OS X - What? Windows? Are You Kidding? ;)

MODULE DEVELOPMENT UNDERSTAND ALL THE PREREQUISITES THROUGHLY

Drupal DB Schema is the most important fundamental - Most importantly, understand: - how content/comments are stored - how taxonomy is stored - how users/ACL is stored

you can't escape the hook Drupal has hooks for everything You can use hooks for: - CRUD operations - modifying anything(almost) at runtime - path/routes definitions - cron tasks, forms, schema definitions - and much much more...

and do I need to say - That you should know: - PHP - Bsic RDBMS concepts & SQL - Good Programming Style - Software Design Skills - learn that from Drupal ;)

so you want to code a new module Let's ask a few questions

Question #1 Is there are a contributed module that has the functionality I need? If Yes, use it. PERIOD.

Question #2 Is there any contributed module that does something similar to I need? If yes, use it, switch off the other functions, if possible

Question #3 Can I adapt any contributed module to do what I need? If yes, adapt it.

code your modules when you need to DON'T FORCE A DONKEY TO RUN A DERBY NEITHER FORCE A STALLION TO PULL A CART

If you need a new content type CCK will save you lot of time

with CCK, use VIEWS a simplified Crystal Reports for Drupal.

when writing modules, you will be... - Creating Forms - Receiving input - Doing SQL stuff - Outputing strings - containing text, html and other content

Learn and understand Form API Form API has lot of benifits - Define forms in PHP syntax - Drupal will generate correct HTML - Makes form aterable at runtime - Makes programatic submission possible

filter out that evil input with check_plain($string) makes sure $string is plain text and filters out those clever scripts and malicious html

It's a full family

filter_xss()

check_markup()

check_url

valid_url()

valid_email()

Drupal has a very powerfull input filter system. LEARN IT – USE IT No Excuses

Learn to construct good SQL. PERIOD. Time to go back to basic RDBMS books

BAD SQL in drupal

$result = db_query(”SELECT *

FROM {node}

WHERE

uid = $uid”);

and good SQL

$result = db_query(”SELECT *

FROM {node}

WHERE

uid = %d”, $uid);

printf style converstion specifications

%d = integer

$f = float

'%s' = sting note the quotes

%b = binary data

%% = percent sign

avoid queries in loops asdasd

<?php

while (some condition) {

$res = db_query(”SELECT * FROM

{table} WHERE

something = something”);

}

?>

sometimes can cost just too much!

Tip: See if you can use map() function

beware of QUERY HELL

In some.module

<?php

$someone = user_load(array('uid' => $uid));

call_some_function($uid = $someone->uid);

?>

and then

<?php

function call_some_function($uid){

$someone = user_load(array('uid'=>$uid));

}

?>

Reloading user again

modules and html REMEMBER Don't output HTML directly from modules BUT DON'T MAKE IT A RELIGION

Take a look at

blog_user_page()

Gerenrates HTML directly

LEARN FROM IT

one more tip NEVER NEVER NEVER use print statemets from inside function AJAX callbacks are exceptions but don't forget to exit() after print

THEMES - Learn and be strong at - HTML/CSS - Javascript/jQuery - Basic graphic design - use GIMP, Inkscape - understand difference between svn and png

always use PHPTemplate - Default theme engine since v4.7 - Simple to learn and easy to use - Made for Drupal, by Drupal [people] - Uses our own PHP for templating - No new language to learn (die smarty die)

use some base theme - well tested - basic stuff is ready - some even have a framework(zen) - you can use zen, framework, base, clean, igniter, etc etc,

do you have a separate designer? - Ask him to - take a look at Drupal generated HTML - learn the id/classes generated by Drupal - learn basics of PHP and Drupal FireBug can help here. http://getfirebug.com

avoid complex logic in tpl.php - Templates are for html not for logic - Remeber: - no SQL in templates - no complex logic in templates - on basic branching and looping more than 2 levels of nesting is ALARM ALARM SITUATION

Other useful stuff - Follow coding standards - coder module can help - its has other tons of features - use devel module - to profile queries - inspect redirects - generate test data/users/taxonomy - debug themes(drupal 6) - and more

drush – drupal swiss army knife - drush = drupal shell - unix scripting interface to drupal - API to build command line tools - a package manager, SQL Tools and ToolBox - Build your own tools and utilities

there is a lot left to cover Let that be some other time

Thank You - any questions? ?