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Recently at TouK we had a one-day hackathon. There was no main theme for it, you just could post a project idea, gather people around it and hack on that idea for a whole day - drinks and pizza included.
My main idea was to create something that could be fun to build and be useful somehow to others. I’d figured out that since Confitura was just around a corner I could make a game, that would be playable at TouK’s booth at the conference venue. This idea seemed good enough to attract Rafał Nowak @RNowak3 and Marcin Jasion @marcinjasion - two TouK employees, that with me formed a team for the hackathon.
The initial plan was to develop a simple mario-style game, with preceduraly generated levels, random collectible items and enemies. One of the ideas was to introduce Confitura Man as the main character, but due to time constraints, this fall through. We’ve decided to just choose a random available sprite for a character - hence the onion man :)
Since we wanted to have a scoreboard and have unique users, we’ve printed out QR codes. A person that would like to play the game could pick up a QR code, show it against a camera attached to the play booth. The start page scanned the QR code and launched the game with username read from paper code.
The rest of the game was playable with gamepad or keyboard.
Writing a game takes a lot of time and effort. We wanted to deliver, so we’ve decided to spend some time in the days before the hackathon just to bootstrap the technology stack of our enterprise.
We’ve decided that the game would be written in some Javascript based engine, with Google Chrome as a web platform. There are a lot of HTML5 game engines - list of html5 game engines and you could easily create a game with each and every of them. We’ve decided to use Phaser IO which handles a lot of difficult, game-related stuff on its own. So, we didn’t have to worry about physics, loading and storing assets, animations, object collisions, controls input/output. Go see for yourself, it is really nice and easy to use.
Scoreboard would be a rip-off from JIRA Survivor with stats being served from some web server app. To make things harder, the backend server was written in Clojure. With no experience in that language in the team, it was a bit risky, but the tasks of the server were trivial, so if all that clojure effort failed, it could be rewritten in something we know.
During the whole Confitura day there were 69 unique players (69 QR codes were used), and 1237 games were played. The final score looked like this:
And the obligatory scoreboard screenshot:
The game, being created in just one day, had to have problems :) It wasn’t play tested enough, there were some rough edges. During the day we had to make a few fixes:
These were easily identified and fixed. Unfortunately there were issues that we were unable to fix while the event was on:
All in all we were pretty happy with the chosen stack. Phaser was easy to use and left us with just the fun parts of the game creation process. Finding the right graphics with appropriate licensing was rather hard. We didn’t have enough time to polish all the visual aspects of the game before Confitura.
Writing a server in clojure was the most challenging part, with all the new syntax and new libraries. There were tasks, trivial in java/scala, but hard in Clojure - at least for a whimpy beginners :) Nevertheless Clojure seems like a really handy tool and I’d like to dive deeper into its ecosystem.
All of the sources for the game can be found here TouK/confitura-man.
The repository is split into two parts:
To run the server you need to have a local MongoDB installation. Than in
server’s directory run:
$ lein ring server-headless
This will start a server on http://localhost:3000
To run the game you need to install dependencies with bower and than
run
$ grunt
from game’s directory.
To launch the QR reading part of the game, you enter
http://localhost:9000/start.html. After scanning the code you’ll be
redirected to http://localhost:9000/index.html - and the game starts.
Summing up, it was a great experience creating the game. It was fun to watch people playing the game. And even with all those glitches and stupid graphics, there were people vigorously playing it, which was awesome.
Recently at TouK we had a one-day hackathon. There was no main theme for it, you just could post a project idea, gather people around it and hack on that idea for a whole day - drinks and pizza included.
My main idea was to create something that could be fun to build and be useful somehow to others. I’d figured out that since Confitura was just around a corner I could make a game, that would be playable at TouK’s booth at the conference venue. This idea seemed good enough to attract >Conclusion
I used to code in Java before I met groovy. Like most of you, groovy attracted me with many enhancements. This was to my surprise to discover that method visibility in groovy is handled different than Java!
Consider this example:
class Person {
private String name
public String surname
private Person() {}
private String signature() { "${name?.substring(0, 1)}. $surname" }
public String toString() { "I am $name $surname" }
}How is this class interpreted with Java?
Let's see how groovy interpretes Person:
public static void main(String[] args) {
def person = new Person() // constructor is private - compilation error in Java
println(person.toString())
person.@name = 'Mike' // access name field directly - compilation error in Java
println(person.toString())
person.name = 'John' // there is a setter generated by groovy
println(person.toString())
person.@surname = 'Foo' // access surname field directly
println(person.toString())
person.surname = 'Bar' // access auto-generated setter
println(person.toString())
println(person.signature()) // call private method - compilation error in Java
}I was really astonished by its output:
I am null null
I am Mike null
I am John null
I am John Foo
I am John Bar
J. BarAs you can see, groovy does not follow visibility directives at all! It treats them as non-existing. Code compiles and executes fine. It's contrary to Java. In Java this code has several errors, pointed out in comments.
I've searched a bit on this topic and it seems that this behaviour is known since version 1.1 and there is a bug report on that: http://jira.codehaus.org/browse/GROOVY-1875. It is not resolved even with groovy 2 release. As Tim Yates mentioned in this Stackoverflow question: "It's not clear if it is a bug or by design". Groovy treats visibility keywords as a hint for a programmer.
I need to keep that lesson in mind next time I want to make some field or method private!
Couple of years ago I wasn't a big fan of unit testing. It was obvious to me that well prepared unit tests are crucial though. I didn't known why exactly crucial yet then. I just felt they are important. My disliking to write automation tests was mostly related to the effort necessary to prepare them. Also a spaghetti code was easily spotted in test sources.apply plugin: 'groovy'As you can see the build.gradle file is almost self-explanatory. Groovy plugin is applied to compile groovy code. It needs groovy-all.jar - declared in version 2.0 at dependencies block just next to Spock in version 0.7. What's most important, mentioned Maven repository URL is added at repositories block.
apply plugin: 'idea'
def langLevel = 1.7
sourceCompatibility = langLevel
targetCompatibility = langLevel
group = 'com.tamashumi.example.testwithspock'
version = '0.1'
repositories {
mavenLocal()
mavenCentral()
maven { url 'http://oss.sonatype.org/content/repositories/snapshots/' }
}
dependencies {
groovy 'org.codehaus.groovy:groovy-all:2.0.1'
testCompile 'org.spockframework:spock-core:0.7-groovy-2.0-SNAPSHOT'
}
idea {
project {
jdkName = langLevel
languageLevel = langLevel
}
}
<project root>To build a project now you can type command gradle build or gradle test to only run tests.
│
├── build.gradle
└── src
├── main
│ ├── groovy
└── test
└── groovy
apply plugin: 'java'This way if you don't want or just can't deploy Groovy compiled stuff into your production JVM for any reason, still whole goodness of testing with Spock and Groovy is at your hand.
public class SimpleJavaClass {
public int sumAll(int... args) {
int sum = 0;
for (int arg : args){
sum += arg;
}
return sum;
}
}class SimpleGroovyClass {
String concatenateAll(char separator, String... args) {
args.join(separator as String)
}
}class JustASpecification extends Specification {
@Unroll('Sums integers #integers into: #expectedResult')
def "Can sum different amount of integers"() {
given:
def instance = new SimpleJavaClass()
when:
def result = instance.sumAll(* integers)
then:
result == expectedResult
where:
expectedResult | integers
11 | [3, 3, 5]
8 | [3, 5]
254 | [2, 4, 8, 16, 32, 64, 128]
22 | [7, 5, 6, 2, 2]
}
@Unroll('Concatenates strings #strings with separator "#separator" into: #expectedResult')
def "Can concatenate different amount of integers with a specified separator"() {
given:
def instance = new SimpleGroovyClass()
when:
def result = instance.concatenateAll(separator, * strings)
then:
result == expectedResult
where:
expectedResult | separator | strings
'Whasup dude?' | ' ' as char | ['Whasup', 'dude?']
'2012/09/15' | '/' as char | ['2012', '09', '15']
'nice-to-meet-you' | '-' as char | ['nice', 'to', 'meet', 'you']
}
} To run tests with Gradle simply execute command gradle test. Test reports can be found at <project root>/build/reports/tests/index.html and look kind a like this.
apply plugin: 'war'in the build.gradle file and create a directory src/main/webapp.
apply plugin: 'groovy'
apply plugin: 'idea'
def langLevel = 1.7
sourceCompatibility = langLevel
targetCompatibility = langLevel
group = 'com.tamashumi.example.testwithspock'
version = '0.1'
repositories {
mavenLocal()
mavenCentral()
}
dependencies {
groovy 'org.codehaus.groovy:groovy-all:2.0.5'
testCompile 'org.spockframework:spock-core:0.7-groovy-2.0'
}
idea {
project {
jdkName = langLevel
languageLevel = langLevel
}
}