Rant

Decided to start ranting about things as I become more of a grumpy old man!
I am not an expert in extjs but have a working competance.

• It is really slow to develop with.
• Memorizing apis and setting keys on objects is dull and leads to messy code.
• The templating system is dirty.
• HTML in javascript is bad.
• Not SEO friendly.
• CSS is clumsy and ugly, just like the rendered html. (You essentially have an empty html document which ExtJs writes to.)
• When you get an error or problem it is common to see the ‘white screen of death’ with accompanying cryptic error messages.
• Testing seems non existant and its really just a method of apple-r / ctrl-f5 and pray.

Mobile Web Development

• Mobile web development is mainly using the advanced nature of webkit CSS3, built-in hardware accelerated animations and using touch events rather than click events.
• Design for the mobile web is a knowledge of what webkit gives you and the ability to work with small screens effectively.
• Mimicking native applications is not the way forward. Look at gmail for iphone as an example of how good custom approaches can be.
• Writing web applications for the mobile web should harness the advantages of a web based approach, not shoehorn a native approach into a monolithic javascript object.

These advantages include:

• Writing HTML and CSS by hand. (lets get semantic man!)
• Unobtrusive javascript. – Javascript is great, unobtrusive javascript is amazing.
• Generating HTML with your favourite web framework (rails, django, symphony). This is powerful but also you need to think about html manifests and caching to not affect performance on shaky connections. If you shift paradigm and think of the web framework as an html generator / ajax interface this helps. (helped me)
• Knowledge of the fancy new functionality that webkit browsers provide is the main new skill required.
• Keeping a lot of your business logic in a web framework allows for easy testing using mature tools.

Canoeing in the Stockholm Archipelago

The plan was to take a trip to the Stockholm archipelago and experience ‘endless islands’ in the most simple form of sea transport.
The sea kayak. We wanted to go as wild as possible so made the decision to try and get kayaks from as far out as possible in the archipelago
so that we were in the wilderness as quickly as possible.

I had only been in a sea kayak once before going on the trip, but had done a wee bit of freshwater kayaking. This proved to be enough, but I was glad
that I had been taught some paddling technique from former world adventure race champion Chris Forne.

Other preparation was to get a few drybags together and to test out some kit which we plan to use on a slightly bigger expedition later in the
summer.

Day 1

I woke up in a large ferryboat approaching Stockholm having been in Helsinki the night before. The last thing I could remember was
doing klinsmans over a bunch of swedes laid out in the corridor. Too much high quality russian vodka had been consumed!

After arriving in Stockholm, priority was to stock up on food. We bought food for the whole trip in one go. There is a wee bit of thinking required to
do this, but its much better having all the food sorted in a oner. Cost about £60 for all the food.

A bus, then a slow ferry took us to the town of Berg on the Island of Moja. From here, it was time to sort out all our stuff and leave the beer soaked
jeans and smelly orienteering shoes behind!

Getting our shit together

After getting maps from the kayak guy, fixing a broken rudder and getting everything packed, we were on our way. We paddled for about 2.5 hours through beautiful thin waterways in the evening sunshine.

We randomly picked a little island that looked like a good starting point for the next day and went about getting out of the boat. Turned out there is a lot of bare rock in the archipelago which has a slimy covering. This means you have to pick out inlets and grassy areas for landing the kayak. We found this out the hard way. First, I got out of the boat and proceeded to fall over and swim in the deep water. Next, I held onto the boat and ‘helped’ Helen get out of the water. The result was she went swimming too!

Sunset with the Kayak

We setup campsite and for the first time felt the sense of peace and chilledness that was to set the tone for the next few days.

Tree Banter

Day 2

The plan for day 2 was to do an 8km open water stretch to reach the Store Nåsa nature reserve. A collection of wild islands in the outer archipelago.

Wilderness

For some reason I was crapping it, the idea of falling out of the kayak in open sea seemed daunting. Luckily nothing with awry and we made it to the islands in the mid afternoon. We setup camp then I tried some fishing with the rudimentary fishing equipment I had taken along. I was unsuccessful but luckily we had enough food to get by.

Jarlsberg and Wine

Day 3

Bantered about the outer islands looking at the protected birdlife and lazing around in the sunshine. We went swimming in the afternoon sun and got attacked by a couple of arctic tern birds.

Arctic Tern

The wind dropped so we decided to make the open water paddle back to the moja reserve. Quick dinner and wine, then hardcore paddling. Open water navigation is difficult, you really need to trust your compass and not your eyes!

We found another top class little island, with a top view and no mosquitos. Best of the trip.

Sweet campsite

Day 4

As we had been carrying all our drinking water (cooking with sea water however) we were running a little low so decided to try and take a detour via a well to get some more water.

Cooking equipment

We hunted for a bit, then had lunch, then tried again and managed to find it! Cold fresh water on a hot sunny day was ideal.

Well

A couple of hours paddling and later we started looking for an island to setup camp. The first one I was attacked by another arctic tern, then at the second one I disturbed a family of toads sheltering in a drying up bog.

We managed to find another camp spot which was pretty sweet.

Sweet Campsite

Day 5

This was the last day of the trip, we left relatively early for us (9:30am) and proceeded back towards berg to return the kayak.

We stopped at a wee town for some lunch then made the paddle back to Berg. On the way we nearly hit a ferry head on and the result was the we had to ride the wake! We hit is straight on a were happy we had spray decks!

When we arrived back in Berg it was midsummer, a big party in Sweden; especially big in moja. There were loads of fast speedboats with noisy engines. I have decided that if I had the pleasure of being able to decide between getting a yaught, or getting a speedboat, I would go for a speedboat any day! Those things are PHAT.

Ended up in 747 that night. (converted into a hostel at Stockhol Arlanda Airport)

Jumbo Hostel

Doing it yourself

Can fully recommend this trip, it was pretty relaxed with not a great deal of physical effort. You could have gone more full on and did bigger kayaking distances than us if you like.

Hired the kayaks from Möja Havskajaker

• Remember you need all your water so make sure you have enough vessels. 2l per person per day is enough.
• Buy all your food before starting the trip. There is a supermarket in Berg but recommend just buying all of the stuff you need in Stockholm as there is more choice in the supermarkets there.
• You can get petrol in the islands so a liquid fuel stove works quite well.
• Watch out for mosquitos as there were quite a few at night so you need a mossie proof tent and the ability to choose good campspots.

Walking into the sunset

I managed to get the time to do some research into Node.js last week. I have been meaning to check out the new coolness for hipster nerds like myself. I will try to explain some of the node concepts as I understand them.

Event based

Concepts borrowed from ruby’s event machine, python’s twisted and the event based closure syntax of javascript.

Often the plan when it comes to scaling request serving in web apps is to use threads. However there is an alternative method which yields better results. This is the single thread event loop and a good example of event based vs threading is that of a load test between apache and nginx.

Apache the worlds most popular webserver. Nginx is a wee russian webserver which punches beyond its weight.

Nginx versus Apache (with the worker-MPM) for serving a small static file.

Because Nginx is event-based it doesn’t need to spawn new processes or threads for each request, so its memory usage is very low.

These graphs are borrowed from this excellent post on the subject

Its all about the IO man

RAM is fast. Disk, DB and Network are very slow in comparison. This results in programs spending a lot of time waiting for IO operations to complete. Node approaches this as being completely the wrong way of doing things and everything should be non-blocking.

The problem being that most IO libraries are blocking, so there is a movement to upgrade these libraries to be non-blocking but there is also a c based thread pool which node uses to achieve non-blocking whilst using blocking IO Drivers.

Event based is hard

Coming from an OOP MVC background is a hard approach direction to Event based programming. A better approach is looking at javascript in the browser and a working relationship with a framework such as jquery which shows how events can be used in the javascript world to achieve unobstrusive RIA functionality to your web application.

Do I really want to build a website with this?

Currently it seems strange to me that you would want to build a website with server-side javascript. There are a lot of great frameworks out there for building web applications and most of them are a lot more mature and powerful than the javascript offerings.

However, I think that the power of node is in the access to low level functionality to build your own low level network applications.

Previously, these areas have been limited to people with black art C skills in memory management and other old school tools. Now, any joe blow with some javascript skills and create something which does some powerful things with good performance.

So essentially, programmers who have grown up in the internet age can now write ace applications in a way which was previously not possible. In my view, this is the main merit of node.

Simple Proxy in Node

To achieve an http proxy you would typically install something like squid which has a lot of configuration options

Obviously squid is very powerful and bursting full of features that you need, you should probably use it actually. However it is really easy to write a proxy in node.

  var http = require('http');
  var sys  = require('sys');
 
 
 
  function server_callback (request, response) {
    var proxy = http.createClient(80, request.headers['host']);
    var proxy_request = proxy.request(request.method, request.url, request.headers);
 
    proxy_request.addListener('response', function (proxy_response) {
      proxy_response.addListener('data', function(chunk) {
        response.write(chunk, 'binary');
      });
      proxy_response.addListener('end', function() {
        response.end();
      });
      response.writeHead(proxy_response.statusCode, proxy_response.headers);
    });
    request.addListener('data', function(chunk) {
      proxy_request.write(chunk, 'binary');
    });
    request.addListener('end', function() {
      proxy_request.end();
    });
  }
 
 
  http.createServer(server_callback).listen(8080);
  sys.puts("Server running on port 8080");

There is a proxy which a little bit more functionality which is available node proxy

How can I have a go?

The easiest installation path I have seen is to install homebrew then

sudo brew install node

You can then launch the proxy example with:

node proxy.js

I want to put it LIVE

Best plan is to deploy it with nginx as a frontend which proxies request to the node instance. One option is using it with upstart and monit.

This blog post describes the process really well. Heroku are in the process of starting of offer node support; but this is still in a closed beta.

Conclusion

I hope this has given a brief overview of node and it helps you to decide whether to have a go or not.