Introduction
Several months ago, a UK-based book publisher, Packt Publishing contacted me
to ask if I would be willing to review one of their books about Django. I
gladly jumped at the opportunity, and I received a copy of the book a couple of
weeks later in the mail. This happened at the beginning of September 2009. It
just so happened that I was in the process of being hired on by ScienceLogic right when all of this took place. The
subsequent weeks were filled to the brim with visitors, packing, moving,
finding an apartment, and commuting to my new job. It was pretty stressful.
Things are finally settling down, so I've taken the time to actually review the
book I was asked to review. I should mention right off the bat that this is
indeed a solicited review, but I am in no way influenced to write a good or bad
review. Packt Publishing simply wants me to offer an honest review of the
book, and that is what I indend to do. While reviewing the book, I decided to
follow along and write the code the book introduced. I made sure that I was
using the official Django 1.0 release instead of using trunk like I tend to do
for my own projects.
The title of the book is Django 1.0 Web Site Development, written by Ayman
Hourieh, and it's only 250 pages long. Ayman described the audience of the
book as such:
This book is for web developers who want to learn how to build a complete
site with Web 2.0 features, using the power of a proven and popular
development system--Django--but do not necessarily want to learn how a
complete framework functions in order to do this. Basic knowledge of
Python development is required for this book, but no knowledge of Django is
expected.
Ayman introduced Django piece by piece using the end goal of a social
bookmarking site, a la del.icio.us and reddit. In the first chapter of the
book, Ayman discussed the history of Django and why Python and Django are a
good platform upon which to build Web applications. The second chapter offers
a brief guide to installing Python and Django, and getting your first project
setup. Not much to comment on here.
Digging In
Chapter three is where the reader was introduced to the basic structure of a
Django project, and the initial data models were described. Chapter four
discussed user registration and management. We made it possible for users to
create accounts, log into them, and log out again. As part of those additions,
the django.forms framework was introduced.
In chapter five, we made it possible for bookmarks to be tagged. Along with
that, we built a tag cloud, restricted access to certain pages, and added a
little protection against malicious data input. Next up was the section where
things actually started getting interesting for me: enhancing the interface
with fancy effects and AJAX. The fancy effects include live searching for
bookmarks, being able to edit a bookmark in place (without loading a new page),
and auto-completing tags when you submit a bookmark.
This chapter really reminded me just how simple it is to add new, useful
features to existing code using Django and Python. I was thoroughly impressed
at how easy it was to add the AJAX functionality mentioned above.
Auto-completing the tags as you type, while jQuery and friends did most of the
work, was very easy to implement. It made me happy.
Chapter seven introduced some code that allowed users to share their bookmarks
with others. Along with this, the ability to vote on shared bookmarks was
added. Another feature that was added in this chapter was the ability for
users to comment on various bookmarks.
The ridiculously amazing Django Administration utility was first introduced in
chapter eight. It kinda surprised me that it took 150 pages before this
feature was brought to the user's attention. In my opinion, this is one of the
most useful selling points when one is considering a Web framework for a
project. When I first encountered Django, the admin interface was one of maybe
three deciding factors in our company's decision to become a full-on Django
shop.
Bring on the Web 2.0
Anyway, in chapter nine, we added a handful of useful "Web 2.0" features. RSS
feeds were introduced. We learned about pagination to enhance usability and
performance. We also improved the search engine in our project. At this
stage, the magical Q objects were mentioned. The power behind the Q
objects was discussed very well, in my opinion.
In chapter 10, we were taught how we can create relationships between members
on the site. We made it possible for users to become "friends" so they can see
the latest bookmarks posted by their friends. We also added an option for
users to be able to invite some of their other friends to join the site via
email, complete with activation links. Finally, we improved the user interface
by providing a little bit of feedback to the user at various points using the
messages framework that is part of the django.contrib.auth package in
Django 1.0.
More advanced topics, such as internationalization and caching, were discussed
in chapter 11. Django's special unit testing features were also introduced in
chapter 11. This section actually kinda frustrated me. Caching was discussed
immediately before unit testing. In the caching section, we learned how to
enable site-wide caching. This actually broke the unit tests. They failed
because the caching system was "read only" while running the tests. Anyway,
it's probably more or less a moot point.
Chapter 11 also briefly introduced things to pay attention to when you deploy
your Django projects into a production environment. This portion was mildly
disappointing, but I don't know what else would have made it better. There are
so many functional ways to deploy Django projects that you could write books
just to describe the minutia involved in deployment.
The twelfth and final chapter discussed some of the other things that Django
has to offer, such as enhanced functionality in templates using custom template
tags and filters and model managers. Generic views were mentioned, and some of
the other useful things in django.contrib were brought up. Ayman also
offered a few ideas of additional functionality that the reader can implement
on their own, using the things they learned throughout the book.
Afterthoughts
Overall, I felt that this book did a great job of introducing the power that
lies in using Django as your framework of choice. I thought Ayman managed to
break things up into logical sections, and that the iterations used to enhance
existing functionality (from earlier chapters) were superbly executed. I think
that this book, while it does assume some prior Python knowledge, would be a
fine choice for those who are curious to dig into Django quickly and easily.
Some of the beefs I have with this book deal mostly with the editing. There
were a lot of strange things that I found while reading through the book.
However, the biggest sticking point for me has to do with "pluggable"
applications. Earlier I mentioned that the built-in Django admin was one of
only a few deciding factors in my company's choice to become a Django shop.
Django was designed to allow its applications to be very "pluggable."
You may be asking, "What do I mean by 'pluggable'?" Well, say you decide to
build a website that includes a blog, so you build a Django project and create
an application specific to blogging. Then, at some later time, you need to
build another site that also has blog functionality. Do you want to rewrite
all of the blogging code for the second site? Or do you want to use the same
code that you used in the first site (without copying it)? If you're anything
like me and thousands of other developers out there, you would probably rather
leverage the work you had already done. Django allows you to do this if you
build your Django applications properly.
This book, however, makes no such effort to teach the reader how to turn all of
their hard work on the social bookmarking features into something they could
reuse over and over with minimal effort in the future. Application-specific
templates are placed directly into the global templates directory.
Application-specific URLconfs are placed in the root urls.py file. I would
have liked to see at least some effort to make the bookmarking application have
the potential to be reused.
Finally, the most obvious gripe is that the book is outdated. That's
understandable, though! Anything in print media will likely be outdated the
second it is printed if the book has anything to do with computers. However,
with the understanding that this book was written specifically for Django 1.0
and not Django 1.1 or 1.2 alpha, it does an excellent job at hitting the mark.