Drupal 7 as an enterprise web application framework

Why as a developer you should use Drupal to build web applications?

Klaus Harris

DrupalCon Munich 2012

Brief bio

• Who am I?• What‘s my Drupal story?

Why this talk?

1. Address some preconceptions that developers have about Drupal

2. Why should I as a developer use Drupal 7

Part 1

Preconceptions

Developer preconceptions

1. Drupal is just a CMS2. Drupal isn’t suitable for large enterprise sites3. It’s old fashioned procedural code4. I’ll have to learn some hideous plugin architecture5. I’ll have to fit around the Drupal data model6. What I can do is limited (it’s just a CMS)7. Theming is difficult8. Drupal is slow9. I can write something like this but better

1. Drupal is just a CMS

We see a lot of comparisons like this:

Drupal vs Joomla vs WordPress Open Source CMS Comparison

CMS Comparison: Drupal, Joomla and Wordpress by Ashleigh Davis on 27 March 2011 | 6 Comments

CMS-Battle: TYPO3 vs Drupal fight over 20 rounds

But not this:

Drupal vs Symfony

Drupal vs Zend Framework

And according to Wikipedia a web framework has:

• Web template system• Caching• Security• Database access, mapping and configuration• Url mapping• Ajax• Web services

http://en.wikipedia.org/wiki/Web_application_framework

So why is Drupal is only seen as a CMS?

• Drupal‘s origins• Comparisons with Joomla, Wordpress and Typo3• No comparisons with PHP frameworks like Zend • Installable software on some hosters• Very node centric data structure in < Drupal 7• Admin interface (horror!)• All those modules, it must be a CMS• Ignorance

node

Teaser Full

Drupal 6 was less flexible

There was only really one content data type built in, namely the node.

Nodes could be sub-typed and had only basic view modes. type

A page is a node for example.

type type type

Node Node revisions

And that data lived in two tables

Drupal 7 changes all this!

Entity API, make:

• your own data table(s)• different view modes• sub-types• fields

AND

you get all the goodneess you know from node API

So now..

node

TeaserFull

Entity

user custom

type

Top 5

RSS

comment

and…

type type type type

TeaserFull

RSS

We aren‘t tied to the Drupal database

We can can override the data operation methods.

meaning…

node

Entity

custom

typetype type

custom

typetype

Drupal DB

Another DB

Web service

Our data can come from anywhere…

• Add fields• Control displayed fields depending on view mode• Get the data into search and define which fields to

index• Use our own view modes• Add custom sub-types• Be data source agnostic• Use all the hooks you are used to from nodes

Entities are new in Drupal 7

BUT!

You aren‘t tied to entities.

If you want, just write your own CRUD code.

What else makes Drupal more web framework?

• URL routing / menu• Actions and triggers• Queue mechanism• Database API• Caching• Form API • Theme system• File API• Roles and permissions• and more..

• Internationalistion• Web services• Testing framework

Contrib gold such as..

• Views• Flag• Rules• Search API

We use actions and triggers extensively

Great fordecoupling

2. Drupal isn’t suitable for large enterprise sites

Wrong!

Look at big sites using it and explore case studies.

Look at the architecture.

• http://www.examiner.com/• http://www.acquia.com/resources/case-study/examinercom• http://www.govtech.com/policy-management/Why-Big-Sites-Run-Drupal.html?page=1• http://buytaert.net/tag/drupal-sites

3. It’s old fashioned procedural code

„It‘s not all OOP“

True. Is that bad? *

„It has global variables“

True, live with it.

„There are so many arrays“

So what? It‘s PHP.

* http://drupal.org/node/547518

4. I’ll have to learn some hideous plugin architecture

You will find it:

• Well architected• Simple• Powerful• Intuitive

Wrong!

Yes!

You will need to learn about hooks, overrides and preprocessing but..

It is easy, you will like it

For example, making a module:

Menu hook

and

page callback

Enable the new module.

Simple!

Let‘s make a block

Simple!

Form API is gold

As a developer you will write a LOT of form code

You should use a Form API that you like.

5. I’ll have to fit around the Drupal data model

Wrong!

Think of Drupal as a web framework with some default data structures set up for you.

• Create data structures via Entities • Just make DB tables and write your own CRUD code• Get data from entirely different DBs• Get data from web services

Power to you!

6. What I can do is limited (it’s just a CMS)

Wrong!

Anything you can build with:

• Zend Framework• Symfony• and so on

you can build with Drupal. With reduced development time!

This search uses Zend Framework Lucene libraries.

Don‘t forget! You can use Zend Framework components in Drupal too!

7. Theming is difficult

No it‘s not.

• Themer - http://drupal.org/project/devel_themer • Devel - http://drupal.org/project/devel• Examples - http://drupal.org/project/examples

Try simple starter theme

• Zen theme - http://drupal.org/project/zen• Basic theme - http://drupal.org/project/basic

Theming is easy

Renderable arrays, theming is even easier.

Devel Themer module

8. I can write something like this but better

Really?

9. Drupal is slow

• Full page caching• Partial page caching e.g. blocks• Static caching with function calls• More efficient Entity loading • Javascript aggregation• CSS aggregation• Master / Slave database configurations• Different caching backends e.g. memcache

Drupal performance greatly benefits from:

• An opcode cache like APC• Memcache

Check out the Drupal performance group: http://groups.drupal.org/high-performance

and some performance related modules such as:

• http://drupal.org/project/memcache• http://drupal.org/project/mongodb • http://drupal.org/project/varnish

Worth looking here..

on any module page.

Part 2

Why should I as a developer use Drupal 7?

1. What is good about coding Drupal 7?

2. What should I be aware of?

3. What mindset change do I need?

4. Where do I go from here?

1. What is good about coding Drupal 7?

• It is amazing what you can build just with modules• Rapid results• Fully featured• Code organisation• Community and resources• There‘s a module for that• Really nice APIs• Developer tools

2. What should I be aware of?

Shock!!

Zend Framework Drupal

Organising code

Up to you

Configuration

And..

Works the same

Deployment can be easier and trickier

Easier through hooks and install pofiles.

Trickier with configuration in the DB. Explore Features module.

Flush the theme registry after theme changes

Flush the menu registry after menu changes

3. What mindset change do I need?

• You will combine modules AND custom code.• Don‘t look for MVC, it‘s more PAC *• Don‘t look for a Zend / Symfony file structure• Understand OO principles in the API ** and see past the procedural code.• Embrace the Drupal way

* http://www.garfieldtech.com/blog/mvc-vs-pac http://www.dossier-andreas.net/software_architecture/pac.html

** http://drupal.org/node/547518

4. Where do I go from here?

Explore

• Drupal.org• Buy a book• Who uses Drupal?

Experiment

• Install Drupal• Try some cookbook site builds

Experiment with programming

• devel, drush, schema, devel_themer modules• Explore the examples module• Write a module

Where could you use Drupal to get started?

• Personal site• An intranet tool e.g. wiki / bug tracker / CRM• New business project• Part of a business presence• Or a hybrid form

The trick is to gain experience.

I started with Drupal via a hybrid model..

Drupal An established B2C website News, help

& FAQ

Main DBMain DBs

Drupal DB

IntranetInternet

Views

Multi-lingual content for news, help and FAQs built in Drupal.

I liked Drupal so much we built on it for a startup

It was a good decision

and is fun!

Thank you for listening

Klaus Harris

klaus@klausharris.de

www.distribly.com

Appendix

Some good books

Drupal 6

Using Drupal - First edition 1, O'Reilly PressPro Drupal 6 Development - Second Edition Apress

Drupal 7

Drupal 7 Module Development - PacktPro Drupal 7 Development, ApressThe Definitive Guide to Drupal 7 - Apress

Some links

http://drupal.org

Developer modules

http://drupal.org/project/admin_menu http://drupal.org/project/devel http://drupal.org/project/devel_themer http://drupal.org/project/schema http://drupal.org/project/drush http://drupal.org/project/examples

Recommended starter themes

http://drupal.org/project/basic http://drupal.org/project/zen

MVC vs PAC

http://www.garfieldtech.com/blog/mvc-vs-pac http://www.dossier-andreas.net/software_architecture/pac.html

Drupal and OOP

http://drupal.org/node/547518