20 Questions I Asked Myself

Bernadette Jiwa is a marketing / branding / idea-spreading expert, (and a Perth local!), and when you subscribe to her “The Story of Telling” she sends you a PDF with 20 questions to ask yourself before launching your next product or idea.

At WWX 2013, this year’s Haxe conference, I’ll be presenting a talk on developing Web Apps, and using “ufront” to do that.  Ufront is a framework made by mostly by Franco Ponticelli, and initially modelled on the .NET MVC framework.  Ufront is pretty powerful, but it’s lacked documentation and hasn’t had a lot of users.  I’ve used it for my last project, added a bunch of helpers, and think it’s ready for some more attention.  A re-launch, if you will.

So I went through the 20 questions Bernadette gives in her PDF, and tried to apply it to ufront, Haxe and web-apps.

My answers to the “20 questions” for ufront (PDF)

It was pretty eye-opening, and really helped me zero in on why I think this approach is better than rails, django, node/express or other frameworks.  I came up with this tagline:

ufront: the client / server framework for Haxe that lets you write the next big (website/web-app/mobile-app/game/thing)


The new Map syntax in Haxe 3

I was using the Haxe3 Release Candidate for well over a month before I realised that the new Map data structures could be created with a nice syntax.  The basic gist is this:

var map1 = [ 1=>"one", 2=>"two", 3=>"three" ];

Like Arrays, but you use the “=>” operator to define both the key and the value.  And Haxe’s type inference is as strong as ever.  Here’s what the compiler picks up:

var map1 = [ 1=>"one", 2=>"two", 3=>"three" ];
$type (map1); // Map<Int, String>

var map2 = [ "one"=>1, "two"=>2, "three"=>3 ];
$type (map2); // Map<String, Int>

var map3 = [ => "Today",*60*60*1000) => "Tomorrow",*60*60*1000) => "Yesterday"
$type (map3); // Map<Date, String>

var map4 = [
    { name: "Tony Stark" } => "Iron Man",
    { name: "Peter Parker" } => "Spider Man"
$type (map4); // Map<{ name : String }, String>

var map5 = [
    [1,2] => ["one","two"],
    [3,4] => ["three","four"],
$type (map5); // Map<Array<Int>, Array<String>>

So it’s pretty clever.  If for some reason you need to type explicitly to StringMap, IntMap, or ObjectMap, you can:

var stringMap:StringMap<Int> = [
    "One" => 1,
    "Two" => 2
$type(stringMap); // haxe.ds.StringMap<Int>

var intMap:IntMap<String> = [
    1 => "One",
    2 => "Two"
$type(intMap); // haxe.ds.IntMap<String>

var objectMap:ObjectMap<{ name:String }, String> = [
    { name: "Tony Stark" } => "Iron Man",
    { name: "Peter Parker" } => "Spider Man"
$type(objectMap); // haxe.ds.ObjectMap<{ name : String }, String>

But if you try to do anything too funky with types, the compiler will complain.  Haxe likes to keep things strictly typed:

var funkyMap = [
    { name: "Tony Stark" } => "Iron Man",
    { value: "Age" } => 25
]; // Error: { value : String } has no field name ... 
   // you are a bad person, and your items are not comprehensible 
   // to Haxe's typing system

Finally, Haxe won’t let you do define duplicate keys using this syntax:

var mapWithDuplicates = [
    1 => "One",
    2 => "Two",
    1 => "uno"
]; // Error: Duplicate Key ... previously defined (somewhere)

If you’re using an object map, it’s only a duplicate if you’re dealing with the exact same object, not a similar one.  For example, this is allowed:

var similarObjectKeys:ObjectMap<Array<Int>, String> = [
    [0] => "First Array object",
    [0] => "Second Array object"
]; // Works, you now have 2 items in your map.

But if you use the exact same object, Haxe will pick it up:

var key = [0];
var sameObjectKey = [
    key => "First Array object",
    key => "Second Array object"
]; // Error: Duplicate Key ...

So there you have it.  A nice feature that I didn’t see mentioned anywhere else.  Thanks Haxe team!



It’s worth mentioning that once you have created your map, you can use array access (“[” and “]”) to read or modify entries in your map.

var map = [ 1=>"one", 2=>"two", 3=>"three" ];

// Reading a value
map[1];   "one"
var i = 2;
map[i];   "two"
map[++i]; "three"

// Setting a value
map[4] = "four";
map[1] = "uno";
map[i] = "THREE";
map;   // [ 1=>"uno", 2=>"two", 3=>"THREE", 4=>"four" ]

Trying to understand dependency injection

Coming closer to the end of writing my first really complex app, I’m beginning to wish I’d taken the time at the start to properly learn and grasp some of the concepts that I see other programmers using.  My client-side code uses a basic MVC pattern, but a bunch of Flash Developers use something that to me comes across as much more complex – as seen in RobotLegs or some of the Haxe ports, such as MMVC.

These frameworks are all about Inversion Of Control (and because we love acronyms: IOC).  And they use Dependency Injection (DI) to do this.  You can see already why the learning curve can be steep, especially if you haven’t come across this pattern before.

So today I googled “I don’t understand dependency injection” and got this fantastic explanation by Kevin William Pang.  I found that really helpful, and I’m sold.  I’d been wondering how the hell I was supposed to unit-test some of my more complex client code anyway… If you’re one that, like me, hasn’t understood this concept in much detail: his article is well worth a read, I won’t bother to try and explain it here.

But, I’m still not sure where the fancy dependency injection tools and frameworks come in.  I see the value in it, and I think “injecting” it into the constructor by using arguments given to the constructor seems just fine.  Meanwhile, the tools which are supposed to help, such as SwiftSuspenders or Minject seem to me to be really verbose, and not offer a lot more than the constructor method.

Maybe that style is more relevant for gaming.  Or maybe it’s benefits show up with more complex projects.  Or maybe I just haven’t been enlightened.

Either way, I’ll try to get enlightened… I think it’s worth spending time learning these patterns.  They’ve obviously gained traction for a reason, and a lot of better developers than me swear by them, so I’ll try wrap my head around it.  Maybe one day it’ll seem as clear to me as MVC, or even OOP do now (both of which took me a while at first).

If you have any suggestions / comments / explanations – I’d love to hear them in the comments section.


Haxe3 Features: Variable Substitution in Haxe3 (aka String Interpolation)

One of my favourite features in the upcoming Haxe3 is also one of the simplest: String Interpolation (also called variable substitution).  If you were using Std.format() in Haxe2, you’ll recognise it.  It lets you do this:

var name = "Jason";
var age = 25;
trace ('My name is $name, I am $age years old.');
// My name is Jason, I am 25 years old

The first point to make is that it is triggered by using single quotation marks (‘), rather than double (“).  If you use double quotes, everything is treated as a plain string:

trace ("My name is $name, I am $age years old.");
// My name is $name, I am $age years old

The next point to make is that this all happens at compile time.  So the trace we made above, in Javascript, would output as:

console.log("My name is " + name + ", I am " + age + " years old");

So you can only do this with strings you have at compile time, as you’re writing the code.  If you want Strings that are given at runtime to have variable interpolation, you should use a templating library like erazor.

Now a few other things to note:

  1. If you want to put in a normal dollars sign, you can use two $, like this:
    trace ('The item costs $20');
    // "20" is not a valid variable name, so it is ignored.
    // Same as ("The " + item + " costs $20");
    trace ('That price is in $USD');
    // Error: Unknown Identifier "USD"
    trace ('That price is in $$USD');
    // Same as ("That price is in $" + "USD");
    var cost = 25;
    trace ('That item costs $$$cost');
    // The first two "$" are for the literal sign, the third is part of the variable.
    // Same as ("That item costs $" + cost);
  2. If you want to access anything more than a straight variable, use curly brackets:
    // Property access
    trace ('My name is ${} and I am ${user.age} years old.');
    // Same as: "My name is " + + " and I am " + user.age + " years old.";
    // Outputs: My name is jason and I am 25 years old.
    // A simple haxe expression
    trace ('$x + $y = ${x + y}');
    // Same as: "" + x + " + " + y + " = " + (x + y);
    // Outputs: 1 + 2 = 3
    // A function call 
    trace ('The closest Int to Pi is ${Math.round(3.14159)}');
    // Same as: "The closest Int to Pi is " + Math.round(3.14159);
    // Outputs: The closest Int to Pi is 3
  3. There is no HTML escaping, so be careful:
    var bold = "<b>Bold</b>";
    trace ('<i>Italic</i> $bold');
    // <i>Italic</i> <b>Bold</b>
    var safeBold = StringTools.htmlEscape("<b>Bold</b>");
    trace ('<i>Italic</i> $safeBold');
    // <i>Italic</i> &lt;b&gt;Bold&lt;/b&gt;
    var safeEverything = StringTools.htmlEscape('<i>Italic</i> $bold');
    trace (safeEverything);
    // &lt;i&gt;Italic&lt;/i&gt; &lt;b&gt;Bold&lt;/b&gt;

There you have it: String Interpolation, one of the most helpful (and easy to comprehend) features of the upcoming Haxe3 release.


Mapping any SSH Server to a Network Drive in Ubuntu

My friend Justin showed me a cool trick this week – mapping any SSH server as a network drive in Ubuntu.  This is really useful for web development, where you have a whole bunch of servers that you have to connect to, transfer files to and from, and make small edits.

The integration is pretty seamless – it shows up in my file browser (just like a local USB drive), I can open files in any app I want, and every time I save the changes are synced back.  Pretty cool.

Here’s how:

  1. Open your Home Folder
  2. In the menu, choose “File -> Connect to Server”
  3. Change the type to “SSH”
  4. Enter the address of your server.
    eg. or
  5. Enter your username and password.
    (Note: If you have public / private keys set up, just enter the username.)
  6. Click Connect

This all comes built in with Ubuntu 12.04.

This is me browsing files on an Amazon EC2 instance, opening a few of them and editing them. Sweet!

Software Engineering

We could have had a great time together

We could have had a great time together.
Instead, you tried to sell me something.

Comment by “Gulliver” on “Creating Passionate Users” blog.

Edtech Haxe

A new project: OurSchoolDiary

So I’m working on a new project that has been brewing in my mind for a while. I’m going to aim to have a working prototype by the end of August, have users beta testing through till December and hopefully have my first paying clients by next year.

A screenshot of some of the first code for the project.

What is it?

The App is called “OurSchoolDiary”. It lets each school create their own School Diary app, where students can sign up and keep track of their homework, assignments and tests. The big win over competing solutions is that here, when the teacher adds an assessment or task, it automatically shows up in the students diary. We’re helping even unorganised students stay on top of their work.

On top of that, we’ll let parents receive emails informing them of their child’s progress. This way parents and teachers can work together to make sure they support their child’s education as much as possible.

And the final advantage, the school gets to show off how cutting-edge they are because they get their own “app”.  Logo and everything!

A Blog

As I go, I hope to keep track of my progress on this blog. (I’ll post to this category specifically, so you can subscribe by RSS).

Why keep a blog?

  • For the history, in case it is ever significant
  • For my own reflection and understanding, regardless of if it is a success.
  • To show off some cool technologies I’m using:
    • Web Apps – I’m not aiming for distribution through the App Store, I’m going a full HTML stack. Not even a hybrid using PhoneGap. This is a page you can view in a browser, and use offline, and the experience will be identical.
    • Haxe – this is a sweet programming language that lets you target Flash, Javascript, PHP, Java, C#, C++ and a platform called Neko. Up until now it’s main success has been in the indie-games market, but I believe it is mature enough to work for a full web-based productivity app.  Client and server. We’ll find out how that goes!
  • To look back on my decision making processes after we’ve launched, and see if my thinking was accurate.
  • To raise interest in the project
  • To explore some of the topics I find fascinating:
    • Usability
    • Design
    • New Marketing
    • Business Strategy
    • Contribution to the community
    • And a few more…

That’s all for now. I’ll try submit a couple of posts a week (at least) until I get this thing off the ground.