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Drupal discovers the world of public-access wiki editing

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200811192054.jpgThose wonderful people in the Drupal community have been awesome citizens and have stepped up to the plate after the Drupal documentation team opened the doors for anyone to contribute to the official online "handbook" documentation.

The previous situation only allowed certain individuals to edit pages, so if while strolling along through the pages you happened to notice an inaccuracy or something you thought you could explain better you had to either write a comment or email the person in charge of it.

Now, after a month-long experiment has worked out nicely, the powers that be have decided to leave the open-editing on so everyone can benefit from the continued goodwill.

Yay! :-D

Learn Drupal by practice, itterations

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I've found that web development as a whole works best by iterative development, using many concepts from Getting Real and other agile theories. This is definitely true of Drupal. When you start off with Drupal you'll start building content types, views and panels galore, and there's nothing wrong with this, it's the best way of getting your ideas out so you can see how they work. You'll also then start dipping your toes into other modules and then writing your own, using books and documentation along the way. Good times.

The thing to remember is to revisit your previous work and improve upon your work: export views to files to speed them up and add an element of revision control; rewrite some clunky SQL queries with improved architecture and views; merge two modules you wrote before and make one that's better; add extra text to node titles for improved search engine accuracy; clean up the CSS and views to work faster and produce more sane output. And on and on..

There's lots to do, lots to learn, don't stop!

Drupal modules: release early, release often (please)

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Something I see quite a good amount of with Drupal modules is a tendency to hold onto fixes committed to CVS for some time. I believe this is counter productive. While yes, it is good to hold onto new, big features until they have simmered for a while and proven to be stable, smaller updates and especially bug fixes, should be rolled out regularly.

A case in point is my recent discovery that certain letters can break customized Views if you use the APIs to change the query from an equality statement to an approximation / SQL "LIKE" statement. The wizard that he is, Earl Miles, who is the lead developer on some of Drupal's most powerful modules including Views itself, took time out of his busy day and replied to my post with a link to a discussion on drupal.org which even included a patch to fix the issue. This was totally wonderful, expected, and I truly appreciate Earl's efforts for doing this.

The frustrating part for me, though, is that Earl himself provided the first patch for this issue back on September 5th, 2007. A whole fourteen months ago! And it still hasn't been rolled into an official release. A known bug, with a patch available from the main author itself, sits unreleased for a year? That's just a little bit crazy.

I believe that the Drupal development community needs to get real and become more agile with their code releases. An active project should not sit for over a year with no releases, there should have been several releases, if only bug fix point releases (Views 5.x-1.6.1 anyone?). And if the project teams can't handle the added workload, perhaps they could ask for some help? I honestly believe this would greatly help the community.

Drupal views queries don't like "silly" arguments

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I had a weird problem with Drupal the other day.

I'm using a module I wrote which uses the views_query_alter() hook to change a views' query from doing "node.title = blah" to "node.title like blah" for a super-simple search engine. Should be simple enough. Well, it turned out that people testing it were having erratic results depending on what they tried to search. At first it was thought that the search was not being case insensitive because searching for "silly" returned no results while searching for "Silly" worked fine, but the database tables were configured correctly (MySQL, table collation set to "utf8_general_ci"), so it had to be something else.

The original query WHERE statement was "node.title = '%s'", so I wrote a function that looked something like this:

function mymodule_views_query_alter(&$query, $view, $summary, $level) {
if ($view->name == 'mycustomsearch') {
$query->where[2] = "node.title like '%%%s%%'";
}
}

Normally this would be processed by the Views module and would turn the query WHERE statement into "node.title like '%silly%'", which is what we wanted. Except that in certain circumstances it wasn't happening like that.

After some digging, thanks to the Devel module, I discovered that the query was actually ending up as "node.title like 'nodeilly%'" if the word entered was "silly". You'll note, first off, that instead of the first percentage sign it says "node". You'll also note that the first "s" is missing. As soon as I saw this I realized what was going on - somewhere the Views module was ending up with the string "node.title like '%silly%'" and for some reason the "%s" part was getting replaced with the table name, i.e. "node". Go figure.

So then came the fix.

As I was in a slight time crunch I didn't feel I had the time to dig further unto the Views code to work out a fix, so for now I just searched for alternative SQL syntax. This seemed odd to me, though, as I was basically looking for another way in MySQL for doing an SQL "LIKE" statement. As it turns out, there is another way - regular expressions.

MySQL supports a set of commands for doing regular-expression-based comparisons using the command REGEXP or RLIKE (one is an alias for the other). The syntax ended up like the following:

$query->where[1] = "node.title rlike '.*%s.*'";

Before I could unleash that upon the world I wanted to filter the input a bit more to avoid potential for security problems. In a rather heavy-handed fashion I set the input string to be filtered as follows, which only allows numbers, letters and spaces through:

$query->where_args[4] = ereg_replace("[^A-Za-z0-9 ]", "", trim($query->where_args[$]));

Putting it all together I finally had a search engine that finally let people search for the word "silly". Go figure.

Note: I do intend delving into the code to work out a hopeful fix for the root problem rather than a workaround in my module, but I felt completing the project sooner was more important than having a 100% correct fix, which will come later.

Overriding CSS can be a pain

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One of the difficulties with Drupal is that with so many modules needed to make a good site you can end up with a dozen or more different CSS files. On occasions when you need to tweak the CSS to match a specific design, or fix something for IE6, it can take quite a while to dig down to the exact definition you need. You might try throwing random snippets of CSS at the problem to try to make it go away, but they usually won't work.

What I've found is that to successfully override CSS you have to repeat the exact same definition as the original, no matter how obtuse it my seem. So if you want to override one simple paragraph you may have to assign some pretty strange CSS, eg.:

* html .span-6 {margin-right: 5px;}

If that's what is already being used, then that's what you have to do to override it.

It may be a bit frustrating, but following that simple guideline has saved my bacon several times.

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