Oh how long without posting, I’ve been missing it dearly, but in transition between jobs I was super busy, and now I can take the time to add some cool stuff =)

Use Case

I’ve been building an API, it is very cool, but the visibility for it is naturally low compared to websites. Loggly offer a great service for monitoring servers via a simple API available in node.js. While this API is cool, it is super broad and require some experimentation to implement an adequate visibility level.

Wouldn’t be amazing to be able to see every request that come in your server and how it respond? Utopic? Absolutely possible!

Implementation

This implementation has been heavily inspired by Connect logger middleware – which is great.

I deeply recommend you to tune it for your visibility needs, though. Make good use: https://gist.github.com/flockonus/5380753

// suggested use:
app.configure(function() {
  app.set("port", process.env.PORT || 3005);
  app.use(logglyMiddleware);
  // ..
  app.use(express.bodyParser());
  app.use(app.router);
  // ..
});

Notes worth taking

• This snippet will show you information in your console when o development
• The info sent might be too much in terms of size or frequency, make good use of customization for your needs
• If you are dealing with a website, I advice you to not send every path hit, it is just too much

Cheers!

In Canada I live in a small room sharing apartment, am experimenting in new job, have to study, cook and clean for myself, smaller number of friends, no actual family nearby.

To summarize: All I have done was with support of friends and family, I am useless by myself. I can also say for sure that I am growing despite all uncertainties. Back then I had too much in my mouth, after a big cleanup I can see better and crave for more!

Friendly advice beforehand; Using http://filepicker.io/ may be a way better idea if you are hosting in Heroku, just make sure if fits your constraints before get hard work done.

Solution Spec

Hard limit file size of the request, so the process don’t block for too long, and don’t blow memory!

If you behind a server such as Apache or Nginx, you can impose a limit to the request size, and you should!

Unless you are in Heroku, and afaik, there is no way to do that, at least just yet. So yes, this can be a major security breach for Rails apps on Heroku.

Given a successful upload, pre-validate size.

The ‘official’ solution attempt to validate the size after the file have been processed. It doesn’t help, since when processing an image rather large (6Mb image consumed 2GB memory in my case) your process will be killed! Letting your website down for some time, and letting your users down as well.

For gifs, take only the first image (less memory consumption too)

When processing .gifs it seems to make a vertical frameset will all the images in the sequence, so it looks like a movie roll, which is not what most people want. Lets just extract the first frame.

Interestingly enough, I found that the processor is invoked for all frames in the .gif. (thanks debugger!)

Solution code

This code takes care the mentioned specs (except for the request size limit), and I think the great advantage is that it avoids opening a file as Image if it fails the size constraint. As well as being very efficient with gifs (only acting on the first frame).
It works on Heroku, with integration for S3, and should work on Amazon Cloud and other VPS.

The shortcome is about handling the exception which is a bit messy involving controller-side logic in a non-automated AR fashion.

Controller

  def create
    begin
    @post = Post.new(params[:post])
    rescue Exception => e
      if e.message == 'too large'
        redirect_to news_path(err: 'file')
      else
        raise e
      end
    end
   #...

uploader

# encoding: utf-8


class NewsUploader < CarrierWave::Uploader::Base

  include CarrierWave::RMagick

  include Sprockets::Helpers::RailsHelper
  include Sprockets::Helpers::IsolatedHelper


  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  def pre_limit file
    #require 'debugger'; debugger
    if file && file.size > 5.megabytes
      raise Exception.new("too large")
    end
    true
  end

  def only_first_frame
    manipulate! do |img|

      if img.mime_type.match /gif/
        if img.scene == 0
          img = img.cur_image #Magick::ImageList.new( img.base_filename )[0]
        else
          img = nil # avoid concat all frames
        end
      end
      img
    end
  end

  version :large, if: :pre_limit do
    process  nly_first_frame
    process :convert => 'jpg'
    process :resize_to_limit => [1280, 1024]
  end

  # Create different versions of your uploaded files:
  version :small, if: :pre_limit do
    process  nly_first_frame
    process :convert => 'jpg'
    process :resize_to_limit => [360, 360]
  end


  # For images you might use something like this:
  def extension_white_list
    %w(jpg jpeg gif png)
  end

end

His talk was mesmerizing and often funny as how casually he mentioned amazing achievements. At early stage, with such a low competition and network effect his product was so succesfull it wasn’t even funny.

Some highlights and inferences from his talk:

• He never made a market research. He was the right man, at the right time, with the right attitude – trying to create a cool dynamic website.
• Scaling was a huge barrier back then. Servers ran in his house, much like Facebook stories. Doesn’t existe anymore nowadays.
• It is a prominent time for “growth hackers”. They are hiring phds from all industries with super developed skills in statistics and complex problem solving – cancer researchers, astro physicists (I can’t get my mind around that. Why not young people?)
• Much more focus on retention than acquisition, probably due network effect and the nature of their service.
• Always focusing on experimentation, throughout deploying and measuring. The man have a deep scientific soul. He admits not to use his own system but have put tons of effort into analyzing the metrics and the impact of the features.
• Plan usually 1 month ahead, due how unpredictable changes take place feels like a waste to think too far ahead.
• His advice: Just push it out of the door, don’t be afraid to crash at small percentage of your users, besides, if the service is good enough not much can make them just flee (apply with discretion, obviously)
• 8 out of 10 feature implementations fail miserably. 1 achieves low results, 1 kind of make it well.
• Even when entering other countries he admitted never to research culture, just experiment with development.
• Operations efficiency is allegedly their competitive advantage, as he mention to use a infinite smaller amount of servers than competitors.
• In one year period they’ve seen their traffic shift from +90% web to 70% mobile app. A trend that have taken Japan a couple of years ago.
• Their strategy still focus broadening and developing the market, while mostly ignoring competition.
• Still experimenting exponential growth. He says he doesn’t care for selling, in the end the money will go to himself as solo proprietor.
• Somebody asked him if he would work with anything else, he said: “After his job working with anything else would be like watch grass growing”

Very glad I attended, intriguing and  inspiring session.

HR is more often than not the deepest take people have in a company they wish to work in.

All these participants will carry a profound impression of the company. It is of extreme importance that HR realize this.

Those who are not called in are likely to carry a negative impression of the company due frustration. But it would be the recruiter minimal obligation to minimize the damage to PR and even maybe turn it into something positive!

Since the daily dynamics recruiters may forget the humans interactions taking place, and more often than not participants are discarded as non-fitting products. Without realizing, by selecting people based on simple text matching of skills and requirements are diminishing the importance of their own jobs.

Head software engineers that shape communities and influence the paths of technology development make lots of fun of clueless recruiters that don’t know what they are doing. The companies that they are recruiting for are mocked.

Not to say, that unless recruiters are in deep sync with both the technologies and products they are hiring people to develop / serve they cannot do a good job! Any correct screen would be sheer luck.

Bottom-line, HR shouldn’t be shallow recruiting somebody with skills x/y/z, must go through a deeper understanding and be as crafty as possible at the process. Much to learn from journalists in this sense.

Frequently interesting insights take place but I don’t write, so they endup dissolved (they are not entirely gone anyways).

Subjects address interesting business topics such as TQM, Six Sigma, Accounting, Competitive Advantage, RH, Capacity Decisions and such will be addressed in future posts.

jQTouch still is a pretty good tool, with performance out-of-the box for old mobiles (being faster then jQMobile), but with some sharp edges.

The problem I deal with in this post may come in a couple of factors, such as:

• When combined with Google Maps, there is an insane lag when panning (scrolling) the map.
• General scroll is slow.
• Some components are slow, particularly when under CSS transition.

At first I thought that either it had a bad interaction with Phonegap, or poor handling of events.

What I find happening that was pretty bad, and almost made me drop it’s use entirely is that it applied some CSS perspective to the body on the bundled apple.css

What a bad perspective..

This made the map feel laggy on the Desktop and incredibly bad on iOS!

So, as solution, you have at least 2 options:

1) Remove the property from the .css

2) After jQTouch has been initialized, run a function that remove  the 3D support flag, like so:

$(‘#jqt’).removeClass(‘supports3d’)

Done! =)

I am assuming you already succeeded providing login to the user; if this is not the case, refer to the docs.

We rely heavily on the FB.api method, the docs make a poorly job documenting, but is a starting point anyway. Also, notice the response is async.

Fetch all user pages (actually the first 5k), but only store the first as var page (this is just a sample)

var page = null;
FB.api('/me/accounts', function(response) { console.log(response); page = response.data[0]; })

Now, we want to publish a post to the page timeline, the thing is, we are not posting as ‘me’ anymore, we must post as the page, and it requires both the id and access_token!
I will make a sample function for it, the response is the post id if it all went well, or an error.

function postToPage(page, msg){
  FB.api('/'+page.id+'/feed', 'post', { message: msg, access_token: page.access_token },
    function(res) { console.log(res) }
  )
}
postToPage(page, 'hello fb-page world')

For last, posting a picture requre the url param, like so:

function photoToPage(page, src, msg){
  FB.api('/'+page.id+'/photos', 'post', { url: src, message:msg, access_token: page.access_token },
    function(res) { console.log(res) }
  )
}
photoToPage(page, 'http://24.media.tumblr.com/tumblr_m1ttif5puW1qcrr0lo1_500.png', 'nyan art')

* Don’t try to run all functions in sequence, since the result comes asynchronously you wont have the var page set.

** kudos for Владимир Дворник answer on Stack Overflow for the url param not documented in the Page Graph API.

*** Security note. The JavaScript SDK can be very unsafe in the case a hacker is able to inject JS code in your page (and even happens in Twitter all the time even though they have millions in funding) they may take advantage of all of the user’s permissions.

Done!


pkgin search ImageMagick # you will get some result like this:
ImageMagick-6.6.6.5 Package for display and interactive manipulation of images
p5-PerlMagick-6.6.6.5 Object-oriented Perl interface to ImageMagick
php53-imagick-5.3.5.2.2.2 Provides a wrapper to the ImageMagick library
ruby18-RMagick-2.13.1nb3 Ruby binding to ImageMagick
ruby18-mini-magick-2.1 Ruby wrapper for ImageMagick command line
ruby19-RMagick-2.13.1nb3 Ruby binding to ImageMagick
ruby19-mini-magick-2.1 Ruby wrapper for ImageMagick command line


Now, install the latest version, today it is 6.6.6.5, so run:

pkgin install ImageMagick-6.6.6.5


Done!

For the Node.js package “imagemagick” at “0.1.2″ works for my use cases, which are just resizes
If you are using other languages you may need the other packages as well.

function uniqueFieldInsensitive ( modelName, field ){
	return function(val, cb){
		if( val && val.length ){ // if string not empty/null
			
			var query = mongoose.models[modelName]
				.where( field, new RegExp('^'+val+'$', 'i') ) // lookup the collection for somthing that looks like this field 
			
			if( !this.isNew ){ // if update, make sure we are not colliding with itself
				query = query.where('_id').ne(this._id)
			}
			
			query.count(function(err,n){
				// false when validation fails
				cb( n < 1 )
			})
		} else { // raise error of unique if empty // may be confusing, but is rightful
			cb( false )
		}
	}
}

Then call it to a field (aka path):

UserSchema.path('nick').validate( uniqueFieldInsensitive('User', 'nick' ), 'unique' )

Recommend you organize all validations in a file for itself, or even a folder if grows too big.

If you have a unique index set for the path you may just save it and check for the error raised; the thing is the format of the error.