I recently found out about coreyoneil collision detection kit for flash as3 and I'm trying to figure out his codes so I can adjust them for my project.
I have some difficulty understanding what the ... means in the CollisionList function of the class. Could anyone tell me what it means?
Here is the class:
https://github.com/tamagokun/Flash-libs/blob/master/com/coreyoneil/collision/CollisionList.as
I haven't done much flash, but I have seen this in other languages like Lua and Java. Googling it can't find me any verification on it though, so I'm kind having faith in my knowledge of other languages.
But, in other languages that use it, the ... must always be the last variable passed to the function. You can append as many parameters to the end of it as possible. Then then name of it (... objs) in your case is an array to access these objects.
Example in a nutshell:
public void printList(... objs)
{
for (int i = 0; i < objs.length; i++)
{
printLine(objs[i])
}
}
Then if you were to call the following:
printList("Thing 1", "Thing 2", "Thing 3");
You would get this output:
Thing 1
Thing 2
Thing 3
EDIT:
I finally found a page with a tutorial about it. Scroll to the bottom. http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WS5b3ccc516d4fbf351e63e3d118a9b90204-7f56.html
Related
Using Flash CC
I have the following array. The first key retrieves the string "Fish" from another array.
static public var comboType_1:Array =
[Constants.level_Data_Edible[Constants.currentLevel],"Frog"];
When I try to iterate over this array with
for(var i:String in hint)
trace(hint[i]);
I get this result:
Fish,
Frog,
function Function() {}
I debug it, it shows the array length is 2.
I googled the function Function() {} and it produces zero hits on Google.
No one has ever heard of this function Function() {} error.
There is no third index, you can see in the array. This error prevents me from iterating over the array. #1065. Variable Function function () {} is not defined.
I'm pretty sure this is yet another Flash bug, but I just want to know the workaround.
Look it is clear that you have discovered how useful static variables can be and you use them as global variables all over your app but since you do not understand when those static variables are instantiated you are running into troubles. If you prefer to blame everything on the technology itself suit yourself but that won't fix your problem and won't make you a better coder. static variables are instantiated prior to anything else in your app so for example using another static variable like that one:
Constants.currentLevel
Is likely to produce error cos whatever the currentLevel is will be ignored anyway. Anything labelled 'current' is a red flag when instantiating static variables cos when static variables are created there's nothing current going on.
The result you are getting and the code you are showing do not match and you only do that on purpose to prove your point. You could show the whole code but you won't cos you know very well that the true mistake (your own code) will be pointed out.
Stop feeling sorry for yourself, stop blaming anything but yourself and post a real question with real code so we can show you where your mistake is.
First, sorry if my english is bad and I'm new to Actionscript 3.
I have a movieclip, I give it an instance name "symbol1" which include a code inside it, like this :
var a: int = 2;
var b: int = 3;
var total: int = a + b;
How can I access the "total" integer variable inside that movieclip in the main timeline? I try to trace it but the result is 0. In the main timeline I wrote this code :
trace(symbol1.total);
I appreciate the help, thanks
The "problem" is the order of execution of frames. The parent is executed first.
The value is 0 and not undefined because the property does indeed exist since the creation of the object which happens in a previous separate step.
You should be able to verify that by stepping through your code with the debugger.
I've made 6 games. each game is in the MovieClip including the game functions, times, scores, variables, etc. I want the total score of each game summed outside each MoviClips, which is in the main timeline. is there a solution to that problem?
This makes your timing problem even more apparent.
You arrive at a frame, which contains a game and you immediately want to access the total score of it. It should be obvious that the game first has to be played in order to obtain a score from it.
Asking a newborn baby what his favourite moment in the first 60 years of his live was doesn't make much sense.
You have to notify the main timeline that the game was finished. The best way to do this is to dispatch an Event from the game. Frames are totally unnecessary.
Your code could look something like this:
var game:Game = new Tetris();
addChild(game);
game.addEventListener(GameEvent.FINISH, onFinish);
function onFinish(e:GameEvent):void
{
trace("finished game with score " + game.score);
}
If you want to update the exterior score sum while the game is running (to immediately reflect any change in the score, not just when the game is finished), your best bet is to create a ScoreModel for the score which you pass to the game, the Game. The Game modifies the ScoreModel, which in turn causes it to dispatch Events:
var score:ScoreModel = new ScoreModel();
var game:Game = new Tetris(score);
addChild(game);
score.addEventListener(Event.CHANGE, onScoreChange);
function onScoreChange(e:Event):void
{
trace("score changed to " + score);
}
Both examples are "what your code could look like"-type of examples. There are many questions about how to dispatch events that explain how to do this in more detail.
Something that came up in the comments from #Jezzamon:
I'm pretty sure you're accessing the variable total correctly, otherwise I would expect it to cause an error (you can test this by trying to run trace(symbol1.variableNameThatDoesntExist)).
No, there cannot be an error for accessing a variable as seen in the question. The reason for that is that the property is accessed on a MovieClip object, which is a dynamic class. As such, the compiler doesn't know if accessing a particular property is valid, because that can change at runtime. And because nothing else relies on the value to be valid, there isn't a runtime error either.
Here's some example code to illustrate this:
trace("toString: " + {}.toString); //toString: function Function() {}
trace("bananas: " + {}.bananas); //bananas: undefined
This is one of the reasons why using MovieClip can be a bad idea. In addition to that, the Flash IDE modifies the code behind the scenes. That can lead to unexpected execution of code. A purely code based workflow sure is advantageous in this regard and recommended.
Hey wondering if anybody can help me, i am trying to add a load of move clips and make them clickable to the stage in action script 3,i can work out the spacing of them later i just keep getting errors while trying to add them using this :
for(var x:int = 1; x <= 10; x++)
{
var this["cardPrint"+x] :MovieClip = new this["card_"+x]();
this.addChild(this["cardPrint"+x]);
this["cardPrint"+x].addEventListener(MouseEvent.CLICK, this["click_"+x]);
}
a point in the right direction would help alot
thank you
this is a scope indicator that indicates the current class. So this["cardPrint"+x] is actually trying to find a variable with that name, but you can't declare a variable that is already a reference.
The only way to do what you want is like this:
public dynamic class Foobar
{
public function Foobar()
{
for(var x:int = 1; x <= 10; x++)
{
this["cardPrint"+x] = new this["card_"+x]();
this.addChild(this["cardPrint"+x]);
this["cardPrint"+x].addEventListener(MouseEvent.CLICK, this["click_"+x]);
}
}
}
The key is making the class dynamic. That allows you to create variable names at run time and to create them in string form using the scope["varName"] syntax. If you are doing this on the timeline in Flash Pro, as I get the feeling you are, this is simply not possible the way you want to do it. You would be better off creating objects in the loop and storing them in an array to access them that way instead of using the syntax described above.
The datatype of each object created will be the same as whatever is instantiated, so you won't be able to set it to be MovieClip or similar.
"card_"+x also needs to be an instantiable object (a Class). If it is not, you cannot instantiate it and it will always error out.
I do want to caution you that is a very poor way of putting this together. The room for error is incredibly large and using this syntax will be difficult to do and difficult to read in your code.
I'm an architect from a strong JavaScript background, but I did some .NET and Java in the past.
However, I wanted to put a hand on ActionScript3, which I was promised that is very related to JavaScript.
As a startup project I took on myself to try port to ActionScript3 one of my favorite assertion utils - should.js - that makes your test codes really pleasant to read.
Updated: 2013-02-19
I saw I confuse with my abstract speaking, so I replaced some of the post with the concrete question in mind.
Here's the full picture:
Consider the following JavaScript code:
Object.defineProperty(Object.prototype, 'should'
, { set: function(){}
, get:
function(){
return new Assertion(Object(this).valueOf());
}
, configurable: true
, enumerable : false
}
);
That is part of the implementation of the JavaScript module Should. The other part is a definition of a the class Assertion, that is constructed with a value, and implements a wide and nice set of assertion methods, against that value. Methods like like
var o = Assertion(actualValue)
o.equals(expectedValue1)
o.moreThan(expectedValue2)
o.contains(expectedValue3)
and aliases to keep english grammer
var o = Assertion(actualValue)
o.equal(expectedValue1)
o.contain(expectedValue3)
and aliases for the lazy sharpshooters, like
o.eql(expectedValue)
o.gt(expectedValue) //greater then
o.gte(...) //greater then or equal
//and so on...
and some connectors that just return this, (which is the instance of Assertion constructed with the test value) like
o.be
o.and
What does it give you?
A test code that looks like this:
var person = getPerson();
Should.exist(person); //that's a static call, and that's easy
//but these are a member calls:
person.should.have("name","age","address","friends");
person.name.should.equal("John");
person.age
.should
.be.number()
.and.be.between(20,30);
person.address
.should
.be.string().and
.startWith("\d").and
.endWith(" st.")
//or even
.and.match(/^[0-9]{1,9}\s+[A-Z][a-z0-9 ]* st\.$/);
person.friends
.should
.be.array().and
.be.between(3,5).and
.containOnlyType(String);
Isn't that wonderful? it's plain English!
You could argue about aesthetics of indentation, where to put the and, and if they are at all necessary, but besides that - anybody can read or write it:
Once you took the 'should' attribute that exists on every object but does not spoil map iterations - you can go on chaining whatever you have to claim regarding the value you started from.
It could have more nifty iteration tools, reflection utilities, be augmented with test functions relevant for your object model, and so on and so forth, but lets just get over the first step :)
But for that, you need every object in the system to feature a non-enumerable smart property called should that in it's getter function returns an Assertion object constructed with the this as the tested value.
(you ain't seen nothing yet - wait to see the beautiful rejection messages it gives! Yummie!!
So yea - I would happily sacrifice the option to call an attribute "should"... and will happily give up intelisense as well - at least as long as it's plain English)
So, in comments, bfavaretto gave us the first step - we know how to prevent enumeration of an attribute - great & thanks!!
Now, can we make it a getter-attribute who's function can access the this?
When I'm done I'm going to put it in some public repo licensed under MIT, for all of us to have fun with :)
Help anybody?
You example is actually 90% correct - but define it like actionscript, not like javascript!
You can still define prototypes in AS3 and they will still work just like prototypes in AS2. The only difference in AS3 is the compiler. AVM2 for some reason does not cast prototypes to native classes (although I didn't test custom classes).
The Prototype Trick: Cast the class as an object.
Eg: if you create:
Array.prototype.random = function():void{}
Then create the object:
var myProtoArray:Array = new Array;
2 things will happen:
myProtoArray.random() //ERROR - this will fail, AVM2 did not map the prototype to Array
but
Object(myProtoArray).random() //WORKS
random() was cast to the Object class, then mapped to Array - I have no idea why!
Hope this helps, cheers.
I confess I'm not keenly familiar with how Javascript works, but if I'm understanding defineProperties purpose correctly, it is a runtime dictation of not just what a property should be, but also the associated namespace to which it belongs (or at least what AS3 considers a namespace).
Class properties are either predefined & only modifiable via custom get() set() functions, or dynamic. Once compiled, their namespace cannot be changed (to my knowledge), so any non-private property is implicitly enumerable, and modifiable whether or not you've written getter/setters (ie: foo.a = value). According to Adobe...
Properties that you create are enumerable, but built-in properties are
generally not enumerable.
That said, you can get a complete list of properties from a class by using describeType. Quite an exhaustive amount of info can be gleaned this way, and I suspect should suit your needs if you wanted to port Mozilla's recreated defineProperties example. Below is an example printing out only property values.
function showProps(obj:*):void {
var desc:XML= describeType(obj);
// public vars
for each (var n:XML in desc.variable){
trace(n.#name + ": " + obj[n.#name]);
}
// getters
for each (n in desc.accessor){
try {
trace(n.#name + ": " + obj[n.#name]);
} catch (error:Error) {
trace("Unable to read write-only property.");
}
}
}
I hope this helps, but I'm certain I don't fully understand what you're trying to accomplish. If you could elaborate, that'd be appreciated.
Ok, guys, thanks for all the help, 22+
I'll give a summary for the people that are interested in the original question, and after that - I'll show you the outcome of my efforts.
The challange was made of two parts:
1 - prevent the augmented (=added on runtime) property from being enumerated
To the first part - thanks to #bfavaretto, commented on the question level - Object.setPropertyIsEnumerable - did the trick great.
2 - make the augmented property operate a getter function with access to the this so it can use it on the constructor of the returned value.
About this second part - Basically - I could not find a way to augment (=add) a property getter to a prototype, and have it operate on instances that enjoy it's API through the inheritance tree.
Anyway, within these limits - here's the outcome:
https://github.com/osher/should.as
Not exact porting because of the platform differences,
and I still have some methods to catch up with the original should.js (like the HTTP testing methods)
but close enough.
The main difference is that instead
var o:Object =
{ name : "Radagast"
, color: "Brown"
}
o.should.have.properties("name","color")
.and.have.property("name","Radagast");
o.name.should.not.equal("Palandoo");
o.color.should.equal("Brown");
you have to go
o.should().have.properties("name","color")
and.have.property("name","Radagast");
o.name.should().not.equal("Palandoo");
o.color.should().equal("Brown");
(the brackets - no getter possible - so the should attribute is a method, and you have to invoke it yourself)
Now if you get stuck and need help from the intellisense, you have to do this:
var should:tdd.Should = o.color.should();
should. <ctrl+space>
which kind'a takes the sting out, but for a peek in the intelisense - it helps
Important
One more thing - you have to force the static constructor of Should as soon in execution as you can,
for example, I do it here:
[Suite]
[RunWith("org.flexunit.runners.Suite")]
public class my_awsome_test_suite
{
//forces the static constructor of tdd.Should
import tdd.Should;
private static var s:Should = new Should();
public var c1:testCase1;
public var c2:testCase2;
public var c3:testCase3;
public var c4:testCase4;
}
I'll probably add some propper README.md later, and more awsome member functions to tdd.Should
Have fun
For a game I'm attempting to develop, I am writing a resource pool class in order to recycle objects without calling the "new" operator. I would like to be able to specify the size of the pool, and I would like it to be strongly typed.
Because of these considerations, I think that a Vector would be my best choice. However, as Vector is a final class, I can't extend it. So, I figured I'd use composition instead of inheritance, in this case.
The problem I'm seeing is this - I want to instantiate the class with two arguments: size and class type, and I'm not sure how to pass a type as an argument.
Here's what I tried:
public final class ObjPool
{
private var objects:Vector.<*>;
public function ObjPool(poolsize:uint, type:Class)
{
objects = new Vector.<type>(poolsize); // line 15
}
}
And here's the error I receive from FlashDevelop when I try to build:
\src\ObjPool.as(15): col: 18 Error: Access of undefined property type.
Does anybody know of a way to do this? It looks like the Flash compiler doesn't like to accept variable names within the Vector bracket notation. (I tried changing constructor parameter "type" to String as a test, with no results; I also tried putting a getQualifiedClassName in there, and that didn't work either. Untyping the objects var was fruitless as well.) Additionally, I'm not even sure if type "Class" is the right way to do this - does anybody know?
Thanks!
Edit: For clarification, I am calling my class like this:
var i:ObjPool = new ObjPool(5000, int);
The intention is to specify a size and a type.
Double Edit: For anyone who stumbles upon this question looking for an answer, please research Generics in the Java programming language. As of the time of this writing, they are not implemented in Actionscript 3. Good luck.
I have been trying to do this for a while now and Dominic Tancredi's post made me think that even if you can't go :
objects = new Vector.<classType>(poolsize);
You could go something like :
public final class ObjPool
{
private var objects:Vector.<*>;
public function ObjPool(poolsize:uint, type:Class)
{
var className : String = getQualifiedClassName(type);
var vectorClass : Class = Class(getDefinitionByName("Vector.<" + className + ">"));
objects = new vectorClass(poolsize);
}
}
I tried it with both int and a custom class and it seems to be working fine. Of course you would have to check if you actually gain any speed from this since objects is a Vector.<*> and flash might be making some implicit type checks that would negate the speed up you get from using a vector.
Hope this helps
This is an interesting question (+1!), mostly because I've never tried it before. It seems like from your example it is not possible, which I do find odd, probably something to do with how the compiler works. I question why you would want to do this though. The performance benefit of a Vector over an Array is mostly the result of it being typed, however you are explicitly declaring its type as undefined, which means you've lost the performance gain. So why not just use an array instead? Just food for though.
EDIT
I can confirm this is not possible, its an open bug. See here: http://bugs.adobe.com/jira/browse/ASC-3748 Sorry for the news!
Tyler.
It is good you trying to stay away from new but:
Everything I have ever read about Vector<> in actionscript says it must be strongly typed. So
this shouldn't work.
Edit: I am saying it can't be done.
Here see if this helps.
Is it possible to define a generic type Vector in Actionsctipt 3?
Shot in the dock, but try this:
var classType:Class = getDefinitionByName(type) as Class;
...
objects = new Vector.<classType>(poolsize); // line 15
drops the mic
I don't really see the point in using a Vector.<*>. Might as well go with Array.
Anyhow, I just came up with this way of dynamically create Vectors:
public function getCopy (ofVector:Object):Object
{
var copy:Object = new ofVector.constructor;
// Do whatever you like with the vector as long as you don't need to know the type
return copy;
}