For two years now, I’ve been riding my bike between home and work which meant Shannon had to rely on the TTC (we both work at Kanetix). That all changed when she purchased a new bike, a 2012 Globe Roll 1. Now I’m happy to say I am the owner of two bikes! (just don’t tell her that)

From a style standpoint, this bike stands out. I’ve gotten more stares, compliments, and questions about this bike than my Fuji Track Classic which is cool, but makes me jealous. Girls seem to dig the colour scheme, but somehow it still manages to appeal to me. Specialized/Globed showed some restraint by not going to town with decals, which adds to the bike’s minimalist look.

The moment I first tried it, I liked how it felt and compared to my Fuji, it has a more relaxed, upright riding position, almost a bit cruiser-esque which I didn’t expect. The bike feels light, fast, and responsive.

On the other hand, the stock 42/17 gear ratio feels too low for me as I’m used to riding at a higher 46/15 ratio, but this would vary between riders. I’ve only tried riding this bike in free-wheel mode, perhaps it’ d be okay riding fixed, but I’d be afraid of spinning out.

Sadly the bike also weighs in on the heavy side, you can definitely feel a difference between the Fuji and the Globe, although it’s not deal breaker. I’d also recommend looking for a new seat as the stock seat isn’t all that great. Speaking of the seat, since it’s white you may end up with some colour transfer from your clothes. If that happens, simply use a magic eraser.

Pros
Cool stock styling
Smooth, responsive ride
Comfortable riding geometry

Cons
Uncomfortable seat
Heavier than it looks
Low crank position means pedal strikes

A client at work required some PDF functionality to reduce the wasted time and effort required to take data from a webapp and handwrite it on a printed PDF form. Since we already had the necessary data in place, I figured it would be pretty easy to do with Perl since I had done it in the past using the Adobe FDF Toolkit and C#.

Thankfully, there are several Perl PDF libraries on CPAN that can help do the job. I checked out four of them with varying results.

PDF::Reuse
Looked like a popular option, but I failed miserably with this module. The interface made me cry and in the end I wasn't able to "reuse" a single existing PDF with it and just got cryptic errors instead.

CAM::PDF
This module worked well at filling text fields, but not much else. Theres a hacky undocumented interface for filling checkboxes and absolutely no support for radio buttons. I also ran into some annoying text positioning issues where the rendered text in each field would display a few pixels lower and hide surrounding elements of the document. Manually modifying the text field (ie. entering a space) in the outputted PDF would reposition the text at the right height and reveal obscured elements. Didn't find anyone having similar issues so I'll give this module the benefit of the doubt and chalk this up to my setup or the PDFs I'm using (hopefully).

use CAM::PDF;
my $file = "/test/form.pdf";
my $pdf = CAM::PDF->new($file);

# get a list of all fields 
my @f = $pdf->getFormFieldList();

my %form = (
    name 	=> "John Doe",
    street 	=> "20 Camden Street",
    gender	=> "Male", # oops radios dont work
    agree	=> "Yes", # oops checkboxes need a hack

);
$pdf->fillFormFields(%form);

# hacky way to fill checkbox
$pdf->getFormField("agree")->{value}->{value}->{AS}->{value} = 'Yes';

print $pdf->toPDF();

PDF::FDF::Simple
This module is a very simple alternative to using the full blown Adobe FDF Toolkit. A FDF (Forms Data Format) file is just a standard file format containing your fields and corresponding text values along with a link associating it with a PDF form. This module will build FDF files for you, but since they are so simplistic, you can be a ninja and build them yourself as follows.

my $file = "http://www.mysite.com/form.pdf";
print qq|
    \%FDF-1.2

    1 0 obj
    <<
    /FDF << /Fields 2 0 R/F ($file)>>
    >>
    endobj
    2 0 obj
    [<< /T (name) /V (John Doe) >>
    << /T (street) /V (20 Camden Street) >>
    << /T (city) /V (Toronto) >>
    << /T (gender) /V (Male) >>
    << /T (agree) /V (Yes) >>
    ]
    endobj
    trailer
    <<
    /Root 1 0 R

    >>
    \%\%EOF
|;

This method supports text fields, checkboxes and radio buttons and results in a perfect looking PDF (unlike CAM::PDF).

Stopping here will require a confusing workflow for your users because they will need to first download a FDF file that will prompt them to download a PDF file at which point they are presented with a merged PDF. Ideally, you'll want to do this merging server side with Pdftk so your users just have to download one final, merged PDF.

You also don't want to do client side merging since you'll have to deal with compatibility issues as FDF files aren't supported by all PDF readers (ie. Preview on OSX).

PDF::API2
PDF::API2 is a feature packed module that let's you do some awesome stuff. Unfortunately, filling form fields isn't one of them. However, what you can do is render text anywhere within an existing, "dumb" PDF. This saves you the trouble of having to spend time setting up a proper PDF form. An obvious drawback of course is that text isn't going to be modifiable by the user.

use PDF::API2;
my $file = "/test/form.pdf";
my $pdf = PDF::API2->open($file);

my $pdf_page = $pdf->openpage(1);
my $pdf_text = $pdf_page->text();

# set font
my $pdf_font = $pdf->corefont('Helvetica');
$pdf_text->font($pdf_font, 12);
	
# draw some text
$pdf_text->translate(200,400);
my $text = "John Doe";
$pdf_text->text($text);

# look ma! i done a checkbox
$pdf_text->translate(100,200);
my $text = "X";
$pdf_text->text($text);

print $pdf->stringify();
$pdf->end();

Rendering requires you get acquainted with PDF style coordinates where 0,0 is the bottom left corner rather than the top left. An easy way to find coordinates for placing text can be done by opening a PDF in Photoshop with no cropping, and a 72dpi setting. Then show the Rulers, and drag them to the bottom left of the PDF. Show the Info panel and you'll get x,y coordinates.

In my case all I needed to do was to pre-fill some text, check some checkboxes and pre-select radio buttons. The PDF I was given wasn't initially setup as a PDF form so depending on what module/method I chose, I would have needed to spend some time setting up interactive form fields within the PDF using Adobe Acrobat. If you don't have access to fully fledged PDF creation software, PDF::API2 text rendering would be your only option.

In the end I went with PDF::API2 as the client just wanted something simple and didn't require the text to be modifiable after the fact. Going forward I'd either use PDF::API2 or PDF::FDF::Simple depending on the requirements.

Recently I had to implement some AES256 encryption for a project I was working on and needed to do it with Perl, but also have it play nice with Oracle just in case the encryption/decryption needed to be done on the database side with SQL.

Sounds simple, but I struggled for a day or two because I wrongly chose Crypt::OpenSSL::AES instead of Crypt::Rijndael. Google seemed to fail me on that one as searching for "aes encryption perl" brings up the former package. I also tried #perl on irc.freenode.net, but that was a big fail as well. Seems you can't expect much help from the monks unless you need simple regex help.

Anywho, here's how you can accomplish this using Perl and Oracle SQL. First we'll use Perl to encrypt a string and then Base64 encode it so it's easy to manipulate and store (otherwise you'll have to deal with binary data).

Perl code

use Crypt::CBC;
use MIME::Base64;

my $cipher = Crypt::CBC->new({
	key			=> "NSTl4XsUKcOWzHVgci9vPF5jZ8Szscz7", # 256 bits
	cipher		=> "Crypt::Rijndael",
	iv			=> "a41ag2wqDSQjzexC", # 128 bits
	literal_key	=> 1,
	header		=> "none",
	keysize		=> 32 # 256/8
});

my $encrypted = $cipher->encrypt("string to encrypt");

# base64 encode so we can store in db
$encrypted = encode_base64($encrypted);

# remove trailing newline inserted by encode_base64
chomp($encrypted);

print "encrypted result: $encrypted \n";

Note that I used a static initialization vector (IV) in my example. Depending on your implementation you may want to let Crypt::Rijndael generate an IV for you. Just remove the iv and header parameters in that case.

Now you can use Oracle SQL to do the decryption. Just replace S06LglP0qfqHVcYXsLeDd1dsCQUrfCpZpJ4tYckk6Ic= with the output of the Perl encrypted string and you should be good to go.

Oracle SQL code

SET serveroutput on;

DECLARE
    encryption_type PLS_INTEGER :=
        DBMS_CRYPTO.ENCRYPT_AES256
        + DBMS_CRYPTO.CHAIN_CBC
        + DBMS_CRYPTO.PAD_PKCS5;
    key_bytes_raw       RAW (32);           -- 256 bit encryption key
    iv                  RAW(32);            -- 128 bit initialization vector
    encrypted_raw       RAW (2000);         -- stores encrypted binary text
    decrypted_raw       RAW (2000);         -- stores decrypted binary text
    decrypted_string    VARCHAR2 (200);

BEGIN
    key_bytes_raw := UTL_I18N.STRING_TO_RAW('NSTl4XsUKcOWzHVgci9vPF5jZ8Szscz7', 'AL32UTF8');
    iv := UTL_I18N.STRING_TO_RAW('a41ag2wqDSQjzexC','AL32UTF8');

    encrypted_raw := UTL_I18N.STRING_TO_RAW('S06LglP0qfqHVcYXsLeDd1dsCQUrfCpZpJ4tYckk6Ic=','AL32UTF8'); -- base64 encoded and encrypted output from perl code above
    encrypted_raw := utl_encode.base64_decode(encrypted_raw);

    DBMS_OUTPUT.PUT_LINE ('Encrypted binary string: ' || encrypted_raw);

    decrypted_raw := DBMS_CRYPTO.DECRYPT
    (
        src => encrypted_raw,
        typ => encryption_type,
        key => key_bytes_raw,
        iv  => iv
    );

    decrypted_string := UTL_I18N.RAW_TO_CHAR(decrypted_raw, 'AL32UTF8');

    DBMS_OUTPUT.PUT_LINE ('Decrypted string: ' || decrypted_string);
END;

So far so good, we can decrypt a value, but really it's not that useful if we wanted to decrypt a whole bunch of rows in a table. We can take care of that by creating a Oracle function that takes an encrypted string and returns the decrypted value we need.

CREATE OR REPLACE
  FUNCTION aes256_decrypt(
      str    IN VARCHAR2,
      key IN VARCHAR2,
      iv  IN VARCHAR2)
    RETURN VARCHAR2
  IS
  BEGIN
    DECLARE
      encryption_type PLS_INTEGER := DBMS_CRYPTO.ENCRYPT_AES256 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5;
      key_bytes_raw RAW (32);
      iv_raw RAW(32);
      encrypted_raw RAW (2000);
      decrypted_raw RAW (2000);
      decrypted_string VARCHAR2 (200);
    BEGIN
      key_bytes_raw := UTL_I18N.STRING_TO_RAW(key, 'AL32UTF8');
      iv_raw            := UTL_I18N.STRING_TO_RAW(iv,'AL32UTF8');
      encrypted_raw := UTL_I18N.STRING_TO_RAW(str,'AL32UTF8');
      encrypted_raw := utl_encode.base64_decode(encrypted_raw);

      decrypted_raw    := DBMS_CRYPTO.DECRYPT ( src => encrypted_raw, typ => encryption_type, KEY => key_bytes_raw, iv => iv_raw );
      decrypted_string := UTL_I18N.RAW_TO_CHAR(decrypted_raw, 'AL32UTF8');
      RETURN decrypted_string;
    EXCEPTION
    WHEN OTHERS THEN
      RETURN str;
    END;
  END aes256_decrypt;

You'll notice I also included 2 additional parameters, key and iv since you might not want to leave sensitive information like that in your database. Now we can do fun stuff like decrypt an entire column in a table.

-- select all rows from users table and decrypt the email column
select aes256_decrypt(email,'NSTl4XsUKcOWzHVgci9vPF5jZ8Szscz7','a41ag2wqDSQjzexC') from users;

So after 8 months, not much has changed for ConcertsTO. I did end up porting over the initial PHP code to Kohana 3 which was quite the ordeal at the best of times. The docs suck, but it’s supposedly one of the best MVC frameworks for PHP5. Part of me wants to do a third rewrite and port it to Django, but don’t think it’s worth the effort.

I did end up adding the search/filter feature which is client side with Javascript, but it’s really CPU intensive and doesn’t work well on mobile phones. Not sure how to optimize it, got any ideas? I still have two killer features I want to add…I swear I’ll get around to them soon.

In an attempt to become more active, I started looking for a bicycle to my commute to work. I already owned a department store 21 speed CCM Riptide, but it weighed alot and was too small for me.

A friend owned a 2009 Jamis Beatnik which looked really sweet and got me interested in getting a fixed gear bike. Despite checking out 4 authorized Jamis dealers in downtown Toronto, I couldn’t find a single Beatnik. They either didn’t have much Jamis stock to begin with so it had to be ordered, or the dealer had suspended their partnership for the year as one rep told me “Jamis has out priced themselves out of the market” which I assume meant they weren’t able to sell them because of their high price.

With the Beatnik out of the equation, I checked out some alternatives, but wasn’t impressed with the 2010 Specialized Langster (ugly colours, and heavy) or the 2010 Trek Soho S (this time just ugly, chain guard, really?)

At the end of the day I walked into Bikes on Wheels in Kensington and saw several 2010 Fuji Track Classics and one or two 2010 Surly Steamrollers. The Fuji was $499 while the the Surly was a hefty $699. I took the Fuji for a test drive and was sold.

It met my main requirements as it was light (sub 20lbs), looked good (gloss black with aluminum accents), and was relatively cheap. The biggest reason I chose to get a fixed gear bike was the cost. To get a good sub 20lbs geared bike for $499 simply isn’t possible and you’ll likely have to shell out close to $1000.

Since buying it, I’ve replaced the stock toe clip pedals with platforms and added a right hand front brake. After a week of riding without brakes, I became deathly afraid of going fast or going down the smallest of slopes as it’s simply not possible to stop a fixed gear bike without planned or skid stopping. Not sure how the couriers and hipsters are doing it, but its just not for me. I used to ride fixed when I was 10 years old and do skid stops, to the point where I had a bare patch where the inner tube was exposed, but I can’t any more. I’m still riding fixed for the work out benefit, but rely on my front brake for stopping.

Pros
Lightweight, close to 20lbs, if not less
Track bars provide several hand positions
High position crank, so no pedal strikes
Pre-drilled holes for bottle cage, and both brakes (oh the horror)

Cons
Scratches easily, cheap paint job?

Lessons learned
Riding fixed with no brakes blows
Riding on busy roads is dangerous, be very careful, and wear a helmet
Don’t signal and brake at the same time
Slow down around street car tracks, trust me