Adam Loving’s BlogSeattle Facebook, OpenSocial, and Web Development

My earlier (rather lame) post on Ruby Regex’s (Regular Expressions) is getting some Google love, so I thought I would supplement it with some more useful information.

If you are searching for Ruby Regex help, my guess is you are looking for…

Validating an email address with a Ruby Regex

Something simple like this next one will get you started.

irb(main):023:0> “me@adamloving.com”.match /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i

For a much more complete email address ruby regex, try:

#
# RFC822 Email Address Regex
# --------------------------
#
# Originally written by Cal Henderson
# c.f. http://iamcal.com/publish/articles/php/parsing_email/
#
# Translated to Ruby by Tim Fletcher, with changes suggested by Dan Kubb.
#
# Licensed under a Creative Commons Attribution-ShareAlike 2.5 License
# http://creativecommons.org/licenses/by-sa/2.5/
#
module RFC822
  EmailAddress = begin
    qtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]'
    dtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]'
    atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-' +
      '\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+'
    quoted_pair = '\\x5c[\\x00-\\x7f]'
    domain_literal = "\\x5b(?:#{dtext}|#{quoted_pair})*\\x5d"
    quoted_string = "\\x22(?:#{qtext}|#{quoted_pair})*\\x22"
    domain_ref = atom
    sub_domain = "(?:#{domain_ref}|#{domain_literal})"
    word = "(?:#{atom}|#{quoted_string})"
    domain = "#{sub_domain}(?:\\x2e#{sub_domain})*"
    local_part = "#{word}(?:\\x2e#{word})*"
    addr_spec = "#{local_part}\\x40#{domain}"
    pattern = /\A#{addr_spec}\z/
  end
end

Find URLs using a Regular Expression in Ruby

Here is a simple URL matching regular expression.

irb(main):028:0> "http://www.adamloving.com/".match /^(http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(([0-9]{1,5})?\/.*)?$/ix

This is a follow up post to my earlier post about watching internet video (Hulu and YouTube) on a TV. Since I still haven’t found a set top box that I can recommend, I thought it would be helpful to describe how to hook your PC or laptop up to your television.

• If you have an older PC or laptop, and an older TV, most likely what you need is an S-video cable.
• If you have a newer PC or laptop and an older TV, DVI to S-video is more likely what you need.
  
• Lastly, if you have a new PC or laptop, and a new TV (like a flat screen LCD TV) - you probably need a DVI to HDMI cable.

Hooking up your PC to your TV can be a pain. Here is another article I found about internet set top boxes. One that looks promising that I didn’t mention before is the “vunow“. The vunow claims to offer NBC content, but I couldn’t figure out where to actually buy it - so it may not be released yet.

It seems like someone just needs to get this hardware done so we can make cable and broadcast TV obsolete.

Image by Abdallah ♫ via Flickr

I don’t understand how Facebook’s new Friend Connect is substantively different from their pre-platform API functionality. External Web sites already have the ability to allow users to sign in to Facebook and retrieve their friends and profile from an external site. Friend connect just appears to be some better UI controls for doing this withouth having to jump off to Facebook and approve the 3rd party app. What am I missing?

UPDATE: you should definitely go with Benjamin Golub’s Python FriendFeed library for App Engine (fftogo). It is cleaner than mine and includes some undocumented API calls (like fetch_entry).

I had to make some minor modifications to the FriendFeed python library to get it to work with Google App Engine. App Engine does not support out urllib2, and has its own urlfetch library.

Here is the cut and paste-able code (see also pastie, I’m having trouble with code formatting in Wordpress)

# original (FriendFeed.py 0.9)
def _fetch(self, uri, post_args, **url_args):
    url_args["format"] = "json"
    args = urllib.urlencode(url_args)
    url = "http://friendfeed.com" + uri + "?" + args
    if post_args is not None:
        request = urllib2.Request(url, urllib.urlencode(post_args))
    else:
        request = urllib2.Request(url)
    if self.auth_nickname and self.auth_key:
        pair = "%s:%s" % (self.auth_nickname, self.auth_key)
        token = base64.b64encode(pair)
        request.add_header("Authorization", "Basic %s" % token)
    stream = urllib2.urlopen(request)
    data = stream.read()
    stream.close()
    return parse_json(data)

# modified
def _fetch(self, uri, post_args, **url_args):
    url_args["format"] = "json"
    args = urllib.urlencode(url_args)
    url = "http://friendfeed.com" + uri + "?" + args
    headers = {}
    if post_args is not None:
        post_data = urllib.urlencode(post_args)
        method = "POST"
        headers={'Content-Type': 'application/x-www-form-urlencoded'}
    else:
        post_data = None
        method = "GET"

    if self.auth_nickname and self.auth_key:
        pair = "%s:%s" % (self.auth_nickname, self.auth_key)
        token = base64.b64encode(pair)
        headers["Authorization"] = "Basic %s" % token

    result = urlfetch.fetch(url=url, payload=post_data, method=method, headers=headers)
    data = result.content

    self.result = result
    self.feed_json = data

    return parse_json(data)

Image via Wikipedia

Yesterday, my co-worker Matt told me about some Gmail tricks I hadn’t heard of. Well, one is a trick, and one is just “nice to know”.

Gmail will ignore (some, all?) punctuation in email addresses. So bob.smith@gmail.com is the same as bobsmith@gmail.com. (That’s the nice to know part).

Furthermore, text after a plus sign is ingored. So, when you sign up for a new service, you can use a unique email address. You could sign up for amazon.com using bobsmith+amazon.com. All your mail will be routed to the same place, but you can block certain services and track who gives your email to spammers.

Image via Wikipedia

I got hooked on FriendFeed and wanted to create a different Web based interface. I wanted to be able to scan through several posts, open their links automatically, comment and “like” quickly, and have the list auto-update to show new posts. For some reason, I haven’t found a desktop client that I like (I tried Twhirl and AlertThingy). The clients are a pretty efficient way to comment (if you can find the right button), but I find notifications too disruptive, and neither client auto-opens links.

So, I created StumbleRead. Give it a try, and let me know what you think by commenting on this post (or below). Also, make sure you catch the hotkeys.

Disclaimer: Works best in Firefox, lightly tested in IE 7 and Safari.

Here are the shortcut keys for StumbleRead, any suggestions for others?

I was thinking I may need to create left hand versions of Next and Previous (so righties don’t have to take their hand off the mouse).

This has bitten me a couple times in the last few days. The Ruby “or” (or equals) operator appears to have a bug where, when used in an assignment, the first value is assigned rather than the results of the entire expression.

irb(main):001:0> x = false || true
=> true
irb(main):002:0> x
=> true
irb(main):003:0> z = false or true
=> true
irb(main):004:0> z
=> false

ruby version: ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.10.1]

I would expect z to be true in that last example.

I spent about 4 or 5 days re-implementing one of my projects on Google App Engine. A basic version of the app is now live, but I’m waiting for the DNS to go through, so I won’t link to it just yet. Overall, I love it. This was my first exposure to Python and Django too - and I really like them.

Some quick pros and cons:

+ Python is really learn-able. I found it to be a easier learning curve than Ruby. Although, Ruby’s elegance will probably still win in the long term.

+ Local development server for App Engine is good. Behaves pretty much the same as the real thing.

+ Deployment easy (still need to figure out how best to do automated testing for Django/Python)

- Bulk load slow both locally and live. Only gripe is the speed of the local simulated datastore (I think it is file system based).

- Had some trouble with Python paths. Just beginner issues.

- Tried both XCode, TextMate, and Aptana (with Pydev) IDEs. Aptana wins because it requires less clicks to get to your file, and also has Javascript and HTML formatting. Pydev auto-complete is so-so, don’t know why you can’t navigate to a library method (maybe I don’t know the hot-key?)

- Bulk upload samples from Google were good learning material, but it probably would have been more time effective to just upload data by doing HTTP Posts to my app.

- No support for bulk delete. Work around is to write a page that deletes as many rows as it can without hitting your CPU/page response time quotas. Even better work around is to modify the “limit” parameter in the query string in the web based data editor so you can manually delete a couple hundred entity rows at a time.

- Not clear what the steps should be for performing a schema change. If you make one to your models, code just runs until you try and load data that doesn’t fit the new types. No way to transform existing rows without loading them all up into a page and saving them. This is going to make future revisions of an app difficult.

- Apparently no option for enforcing referential integrity (understandable given the goal of scale)

The restrictions on GQL and the App Engine data store count as both a benefit and a limitation. Even in my simple app, I was forced to denormalize and add more columns than I would’ve liked to satisfy the requirement for an index to match every query. My app is mostly read-only right now, adding more write logic will require updating these denormalized columns. As I gain more experience, and GQL gets richer, I don’t think this will be a problem compared with the huge scaling benefit. The App Engine “sandbox” just forces you to do your optimization work up front.

So what kind of apps will work well on App Engine?

Given its infancy, it is hard to see very data-intensive apps working on App Engine. It does look like the perfect environment for hosting mashups and Facebook/OpenSocial apps. Also, I expect a thriving ecosystem of simple open source App Engine components (a blog, a wiki, etc.) that can stiched together.

It’s the Beginning of the End for the TV Biz, Says Analyst | Epicenter from Wired.com

“We believe the feature film and TV content businesses are on the verge of structural changes that appear to impact the core revenue and profits of entertainment business models,” wrote DiClemente.

Viva la revolution! I just discovered Strike.tv last week. Just show me a way to watch Hulu and YouTube on my TV and I’ll be happy. Oh, and better quality re-streamed Tour de France coverage.