The AADL Developer's Blog. Technical info about what new features we're working on, releasing, and playing with.

Talking to CalDAV from PHP

Our internal room reservation system runs as multiple bookable calendar resources on our Zimbra email system. In order to reserve rooms for our website events, I have created a custom drupal module that hooks into the drupal node save process and places the event information on the correct calendar. The full module is not ready for the public (yet), but here's a sample of how we use the caldav-client PHP library from the Davical open source project.

In this PHP example, I will include the library, create an object of the CalDAVClient class, connect to a CalDAV Calendar, and get details about the calendar:

$cal_url = '';
$cal_user = 'username';
$cal_pass = 'password';
$cdc = new CalDAVClient($cal_url, $cal_user, $cal_pass);

$details = $cdc->GetCalendarDetails();

If you are able to connect to your calendar correctly, you should see something like this:

CalendarInfo Object
    [url] => /dav/
    [displayname] => Calendar
    [getctag] => 1-98765
    [calendar-timezone] => BEGIN:VTIMEZONE


The CalDAVClient library includes functions to get specific events from the calendar, place new events on the calendar, and additional functions to interact and modify your calendar from your PHP script. It's an excellent foundation for building more specific calendar interactions in your script.

DAViCal source code:
DAViCal project:
Zimbra email server:

Tool Evaluations: Code Editors

I've recently switched away from a two-computer desktop (Linux workstation with a Mac laptop on the side), to a single Mac laptop with multiple monitors. As part of the transition, I've been looking into the new possibilities for my primary code editor on OS X coming from Ubuntu. I primarily write PHP code, and am frequently working on Drupal modules. Here's a list of some of the apps I've been evaluating:

Komodo Edit (Free)

My longtime favorite, which I've been using as my primary code editor for the last 7 years.

Pros: cross platform, free, autocomplete, code hints, extendable, New Source Tree sidebar module.
Cons: Some display bugs with multiple monitors make the autocomplete and lookup popups appear on the wrong desktop, autocomplete not working

Some of the bugs I'm seeing while using Komodo Edit on my new machine may be configuration errors on my part, but the popups appearing on the wrong monitor are a known issue. I have a feeling I may end up coming back around to Komodo Edit eventually, just because it's so familiar and it does the things I need so well.

Coda ($75 in the App Store)

Coda comes from Panic software, creators of high quality OS X software. Aimed primarily at the Web Development audience, Coda looks great and makes it easy to work on a remote set of files.

Pros: native OS X interface, clear grouping of projects into "sites", custom autocomplete, extendable with plugins
Cons: price, autocomplete is local to current file only

Coda is very easy on the eyes, I just wish it was easier to get site-wide autocomplete with hints. I need to be able to call custom functions from one drupal module to another without having to open the file and copy the function name.

Sublime Text ($70)

Sublime Text is my current goto for code editing, is a strong favorite for OS X developers and has a great feature set.

Pros: Extensive and powerful keyboard shortcuts to get around your code quickly, edit multiple selections simultaneously (e.g. change all instances of a variable name to another name on the fly), large selection of packages for extention
Cons: bit of a steep learning curve for keyboard commands and package installation. Only local autocomplete

I'm still learning how to get around in Sublime Text, but I'm optimistic that I'll be able to get it to do the things that I want it to with a bit of time and experimentation with some of the custom packages. While it does cost $70 to register, there's no set limit on an evaluation copy, so go give it a try.

Komodo Edit:
Sublime Text:

Partner Project: UMS Rewind

Congratulations to the University Musical Society for the recent launch of their online performance archive, UMS Rewind. We were partners on the project, providing the back end infrastructure for the data entry and editing. The project has grown over the years with many people putting in many hours of hard work. It's great to see it online and accessible to the public.

The archive contains thousands of performances, artists and works from 135 years' worth of concerts, and will be updated every season. Many of the performances link to programs and photographs in our collection of UMS materials.

The site is currently in beta, so let them know what you'd like to see.

UMS Rewind
AADL's UMS materials

Stuff We Like: littleBits Synth Kit

We have a ton of cool music tools here at the library and during some down time last week I was able to play with one of our latest acquisitions for evaluation: The littleBits Synth Kit. littleBits are awesome circuit building pieces, held together with magnets. They've partnered with synthesizer giant Korg to offer a kit that contains authentic synth modules that can be chained together to create custom sounds. Here's a little sample of what I was able to put together:

This particular kit is still under evaluation, but you should explore our ever-growing collection of Music Tools!

AADL Music Tools:
littleBits Synth Kit:

Custom Barcode Scanning from your iPhone

We have a lot of items on our shelves, and each one of them contains a wealth of related information within our catalog system. But it's a pain to have to physically carry a item from the shelf to a computer to look up that data, which pales in comparison to hundreds of items on a cart or shelf. It'd be great to have a way to look up that information on a mobile device, ideally by entering the item's unique barcode number with a scanner.

First I built a drupal module that displayed the basic information we wanted for each item, and I added the barcode as an argument at the end of the page's URL. As a result, if you knew the item's barcode, you could open a web browser and type in the address + the barcode to automatically go to a page with the information you wanted.

Secondly, I looked for an App in the iTunes App Store which could do actual scanning of the barcode using the iPhone's camera. There are a TON of barcode scanners in the App Store, but the vast majority of them are tailored to scanning UPC codes and redirecting you to online retailers for the corresponding product, or to decode custom QR codes.

After checking about a dozen free Apps with no luck, the App I finally settled on was mobiscan, which cost $3. But it fulfilled the two requirements for this simple project:

  1. Scan a barcode in the codabar format
  2. Redirect to a custom URL with that barcode's value

There are other, similar apps that offer even more custom functionality, or even integration with your own iOS app. But for the quick and simple scan and go functionality, mobiscan worked the best.

mobiscan App:

Printing Labels from Drupal to a Zebra printer

Some of our large items have multiple pieces, and to keep track of them we place the same barcode label on each piece. Making multiple item barcodes is a tedious process, so I created a simple function as part of our drupal intranet to create a new item label from the barcode number:

function spew_print_barcode_label($barcode, $printer, $num) {
  $header = variable_get('spew_barcode_header_text', NULL);

$zpl = <<<ZPL
^FX/* Top text line */^FS
^FX/* Barcode */^FS
^FX/* Bottom Text Line */^FS

  for($i = 0; $i < $num; $i++) {
    try {
      $fp = pfsockopen($printer, 9100);
      fputs($fp, $zpl);
    catch (Exception $e) {
      drupal_set_message('Caught printer connection exception: ' . $e->getMessage(), 'error');

The function creates a string of ZPL commands, and sends them directly to the printer on port 9100 by opening a socket connection using pfsockopen(). This should save our materials processors a lot of time.

Summer Game Prize Fulfillment Workflow

The AADL Summer Game has an online shop where earned points can be spent on awesome schwag. To try to make it easy for the volunteers and staff to fulfill the orders we took advantage of some of the infrastructure we already had in place for other parts of the site.

As some know our hold notices currently go through a script that sends an email along with printing a custom label to a label printer, that is used for identification on our hold shelves. We reused this process to print a custom pickup/order label every time an order comes through the ubercart game shop by hooking into the payment process. This leaves a spool of order labels that those doing fulfillment can pick up throughout the week and start filling. A spool that has been increasing dramatically in length. This makes it easy for the shop keepers to keep on top of all the orders and properly mark the bags for pickup.

The Summer Game Shop is live and we have our first order labe... on Twitpic

As orders are filled the barcode on the custom label is scanned, which sets the order as fulfilled and adds a notification job to a redis queue. Players have the option of getting SMS notifications (sent through Twilio) or email. Shop keepers can also cancel orders if need be which refunds the points to the player account.

After the items are delivered to the branch destinations on Friday morning, a script goes through the jobs on the redis queue and sends the notifications letting players know their items are ready for pickup.

Our first batch of Summer Game stuff  (380,000 points worth),... on Twitpic

More background info on our Summer Game is in the works and keep that order spool growing!

Under the Hood of the AADL Summer Game

The 2011 Summer Game has brought big changes to the way we play here at the library. In addition to the "classic" summer reading game, players can earn points for writing reviews, adding comments and finding game codes at events and locations. Players also earn badges for special accomplishments. We just passed player ID #4000 and we still have weeks to go for even more players to join and earn points and prizes. The pieces that make up the Summer Game are diverse but by adding custom code to the solid foundations provided by these open tools we've been able to concentrate our efforts on adding new content and functionality rather than chasing bugs and putting out fires. Here's some of the tools and technologies that make up the Summer Game:

Drupal: The websites run on the Drupal Content Management System. In addition to giving us a framework for writing blogs, creating user accounts and writing comments, it has a extensive API which allows us to leverage those pieces to add our own functionality. A drupal module for Summer Game was created that keeps track of player data, lets players add points through multiple activities, and displays a leaderboard. Players are attached to user accounts, and a simple function which could be placed in any code that runs the site allows us to award points for any website action. The summer game module is available through github: Summer Game module.

Request for Others and SOPAC

Over the past few years we've taken advantage of having a catalog we can tweak and change. Recently as we've been able to store more data outside of the ILS we have gone the route of making our catalog one of our main development platforms.

However, staff still had to go back to the staff client for the ILS for some functions. While many of those functions don't really make sense as part of the catalog, requesting items for other patrons was one that did. Having full control over the search and what fields are indexed created a back and forth between the client and website for finding things.

We just rolled out the feature for staff so they can request for others via the public catalog (if they have the permission). Its a feature I'd recommend looking at implementing if you are working on an opac replacement or other catalog like feature.

request for patron

Just one more step moving more non-inventory things to the drupal/sopac side of things rather than the ILS.

Patron Comments Module Released

We've decided to release the source code that drives our handling of patron comments; It was one of the first custom drupal modules that our dev team developed for our use here at the Ann Arbor District Library when we started with drupal 4 in 2005. It was migrated to drupal 6 along with the rest of the site in 2009. It stores comments both from online and our record of hand-written comment cards. It also handles the thousands of title suggestions we receive online every year.

Currently we have just over 46000 comments stored in the system, and every time you contact us, we save it. Don't forget that in addition to submitting a comment, you can browse the comments that we have published for public information, good, bad and everything in-between.

About the module itself: it's written for drupal 6, and requires a fair amount of custom setup in a MySQL database by hand before all the pieces fit together properly. If you want to give it a spin, make sure you look at the README.txt file for installation and setup procedures. Grab it from our github repository at the link below.

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