I was reading a tutorial about creating multiple levels, and the below really interested me on how i should go about this.
It may seem natural to make one class per level, with each class
extending AvoiderGame, and use events to switch between them. So, we
might have classes named AvoiderGameLevelOne, AvoiderGameLevelTwo,
etc., and let each one fire off a “NavigationEvent.NEXT_LEVEL” when
appropriate. Presumably then the document class would listen for this
event, and when it heard it, it would run “playScreen = new
AvoiderGameLevelTwo()” (or whichever level was appropriate), and pass
through all the information such as score and time to this new
playScreen instance.
I'm not entirely sure on how to go about this. I put my stage, which is an array of tiles in a class called level1, level2, etc and had it extend my main class. Just to check if everything works, I added a public static var called levelArray in my main, which is a blank array. Then in level1, I pushed my array into levelArray.
So for my level1 class
package {
public class Level1 extends Main {
public var floor1:Array = new Array();
floor1[0] = [2,1,1,1,1,1,2];
floor1[1] = [1,1,1,1,1,1,1];
floor1[2] = [1,1,1,2,1,1,1];
floor1[3] = [1,1,1,1,1,1,1];
floor1[4] = [1,1,1,2,1,1,1];
floor1[5] = [1,1,1,1,1,1,1];
floor1[6] = [2,1,1,1,1,1,2];
public function Level1() {
Main.levelArray.push(floor1);
}
}
}
Doesn't seem to be working. levelArray comes up as blank. Might be because the two classes aren't communicating with each other correctly? Any ideas if I am approaching this the correct way?
I dont know if the rest of your concept is sound, but I think the syntax is off for the part you have shown. try:
package {
public class Level1 extends Main {
public var floor1:Array = new Array( [2,1,1,1,1,1,2],
[1,1,1,1,1,1,1],
[1,1,1,2,1,1,1],
[1,1,1,1,1,1,1],
[1,1,1,2,1,1,1],
[1,1,1,1,1,1,1],
[2,1,1,1,1,1,2]
);
public function Level1() {
Main.levelArray = floor1;
}
}
}
EDIT: if the only thing distinct about each level is the array that forms the floor, you may consider the fact that you do not need a new class for each level, just a new array. you can define the arrays for each level in the class that is super to this one and then just replace them with each progression.
Related
I am creating a platformer in flash as3 and i want to pass the var Score for my score from Scene 1 to the next. However, I realized the best way to do this was to store the score inside a class, but I am having trouble referencing the variable inside the scenes. Please help. This is the code currently inside the class
package file_as{
public class CS{
public function CS(){
public var Score:Number = 0;
}
}
}
I tried to reference the score in scene in the frame containing my code my stating
CS.Score
But that didn't work so I'm lost.
To access it by doing CS.Score you would need to make that property static.
Static vars/methods belong to the class itself (CS in this case), if not static, they belong to instances of that class (eg var csInstance:CS = new CS(); csInstance.Score = 6;)
Here is how to make it static:
package file_as{
public class CS{
public static var Score:Number = 0;
}
}
As an aside, your current class code should be throwing an error, as you can't have the public/private keywords inside a function. Also, since you defined the var inside a function (the constructor in your case) it would only be available in that function. Notice how in my example above the var definition is at the class level.
All this said, I believe that if you defined a score var on your main timeline, it should be available across different scenes.
I have a problem and I'm not too sure the best way to resolve it.
Scenario:
I have a Super Class called 'food' and I have 20 different foods and extends 'food' like Pizza, Curry, Fish and Chip etc.
When I remove a 'food' I keep a record of it so I can reuse (for performance purposes). Can I make a new Pizza class that uses an old 'food'?
E.g.
public class Pizza extends food
{
public function Pizza()
{
super = FOOD.returnUsedFoodClass();
}
}
Is this possible or would I need to save the extending Class as well?
Hope this all make sense.
EDIT:
When I say remove I mean I no longer need it - so I would normally remove all references to it. But instead, I have placed all 'food' classes that I no longer need in a static vector so I can reuse them later.
You misunderstand the basic OOP principles here.
First: a constructor runs only once and only when the object is created so any attempt to stop the creation of the object or replace the object from within its constructor is illogical and cannot succeed since the object at that moment is already created.
Second: Classic misunderstanding of the super keyword. No super doesn't point to any other instance of any other object, super in constructor points to the super class implementation of the constructor. Trying to assign an object to super cannot work and is also illogical. I'm guessing you meant to use 'this' which would also not work anyway.
What you are trying to achieve cannot be done that way and this in any OOP language. There's no way to run a constructor (meaning creating the object) and make this object point to something else within its own constructor. What you are looking for is a classic object pooling system via static methods like this:
var pizza:Pizza = Food.getFood("pizza") as Pizza;
Where the static method checks if any Pizza instance (from the pool) is available and if it is it returns it and if it's not it creates a new one and returns it.
Pooling can be implemented loosely or explicitly, I prefer the more solid and flexible explicit version. Here's an example:
Food class pooling additions:
static private var recycledInstances:Vector.<Food> = new Vector.<Food>();
//hold our reclycled instances
public function recycle():void
{
var index:int = recycledInstances.indexOf(this);
if(index >= 0)
{
return;
}
recycledInstances.push(this);
}
//explicitly add this instance to recycle
private function reset():void
{
}
//to run in constructor and when the instance is retreived from recycle
//this method purpose is to reset all values to default.
Now when an instance is no longer used you call the instance recycle() method to place it in recycle. Then when you need a new instance you do:
var food:Food = Food.getFood();
And this is implemented that way in Food class:
static public function getFood():Food
{
if(recycledInstances.length)
{
var totalInstances:uint = recycledInstances.length;
var instance:Food = recycledInstances[totalInstances - 1];
instance.reset();
recycledInstances.length -= 1;//faster than splice
return instance;
}
return new Food();
}
You can extend this easily to descendant of food class by adding a type member variable to Food for example and check the type of recycled instances before returning them.
Is there a way to pass an object reference to a component directly from the property/component parameter window? Using the [Inspectible] tag only allows me to input strings and not actual object references.
For example, I have a custom component called "knob" which should hold a reference to a door on the stage which it opens. I know this can be easily done in code with "knob.door = someDoor;" but since there are many objects in the scene I would prefer if I could do it visually trough the properties window.
I don't think you can do this. Your best bet is to pass in a string identifier (perhaps a whole dot-separated path if your clips are deeply nested), and then implement code inside your custom component to find that item by name.
I've got a custom component which lays itself out relative to horizontal and vertical predecessor components, so I do this:
protected var horizontalPredecessor:String = "";
[Inspectable(name = "HorizontalPredecessor", type = String, defaultValue="")]
public function set HorizontalPredecessor($value:String):void
{
horizontalPredecessor = $value;
drawNow();
}
override protected function draw():void
{
if (parent)
{
if (horizontalPredecessor != "")
{
var hp:DisplayObject = parent.getChildByName(horizontalPredecessor);
if (hp)
{
x = hp.y + hp.height + horizontalSpacing;
}
}
}
}
... which is made easy because all these components share the same parent.
Alternatively, if there's only one door, you could make it a singleton, and give it a static reference, like this:
public class Door
{
private static var _singleton:Door;
public static function get Singleton():Door
{
if(!_door) _door = new Door();
return _door;
}
}
Then your handle can just refer to Door.Singleton and you don't have to worry about passing anything in. Alternatively, you could have a static array of Doors in the Door class, and give your handle an index number to link it to a specific Door.
I have a movie clip with an external class attached.
here is the MC code (I've shorten it only for the relevant part...)
package {
//all the imports here...
public class mc_masterChapter extends MovieClip {
public function mc_masterChapter() {
trace (picFile,strChapTitle);
}
//Properties
public var picFile:String;
public var strChapTitle:String;
}
}
In the main class file I'm adding this object to stage using addChild:
var masterChapter:mc_masterChapter = new mc_masterChapter;
masterChapter.picFile = "pic_Chap1.jpg";
masterChapter.strChapTitle = "ABCD:
addChildAt(masterChapter,1);
now, the trace in the MC class code gives nulls to both parametes but if i put a trace inside the MC timeline (instead of the attached class code), it gives the right value!
how can I access the values from the MC class itself without getting nuls?
Thank you.
It works! Let me explain:
var masterChapter:mc_masterChapter = new mc_masterChapter; // Calls class constuctor
// so calls trace() too!
// You will get null null
masterChapter.picFile = "pic_Chap1.jpg"; // Assign the variables
masterChapter.strChapTitle = "ABCD"; // so they can be read
trace(masterChapter.picFile, masterChapter.strChapTitle); // Should trace pic_Chap1.jpg ABCD
If you add the following method to your class:
public function test():void {
trace(picFile, strChapTitle);
}
Then call masterChapter.test() it will successfully trace those two properties. So yes, the class can read its properties.
Make the var you use in your main class public static vars.
OK!
I solved the mystery.
I put two traces. one in the main MC class saying "hey, I'm inside the MC - the picFile="
and one in the put Function saying "I'm putting this file into picFile:"
well this is what I've got:
hey, I'm inside the MC - the picFile=null
I'm putting this file into picFile:image.jpg
got it!?! at the moment I asked him to give birth to an instance of the MC (even before putting it on stage - just defining the object (with this line:)
var masterChapter:mc_masterChapter = new mc_masterChapter;
it allready run the class, so of course that in this stage the parameters were not defined allready and were null.
the definition code came right after that line (in the main.as)
masterChapter.pic="pic_Chap1.jpg";
so what I did, was to move all the code from the main class of the MC object to a public function inside the same package called init(). Then I called this function manually from the parent main class.
By that I can decide when to call it (after I declare all the parameters of course).
That's it.
god is hiding in the small details : )
tnx for all the helpers.
Possibly a better solution would be to use a getter/setter pair, so you can know at the exact moment the properties are set:
protected var _picFile:String:
public function get picFile():String {
return _picFile;
}
public function set picFile(value:String):void {
if (value != _picFile) {
_picFile=value;
trace('picFile set to', _picFile);
}
}
I am currently working with some code that my co-worker wrote. Here is a simplified look at it:
The People class:
package model{
public class People extends Array{ // NOTE: it is not dynamic
public function toXML():XML {
var out:XML = <people/>;
for each(var per:Person in this){
out.appendChild(per.toXML());
}
return out;
}
}
}
Which is basicly an Array of Persons:
package model{
public class Person {
public var name:String;
public var phoneNumber:String;
public function Person(name:String, phoneNumber:String){
this.name = name;
this.phoneNumber = phoneNumber;
}
public function toXML():XML {
var xml:XML = <person/>;
xml.#name = name;
xml.#phone = phoneNumber;
return xml;
}
}
}
This is basicly how my co-worker is using the code:
var people:People = new People();
people.push(new Person("Jake", "902 825-4444"));
people.push(new Person("Bob", "514 444-3333"));
return people.toXML().toXMLString();
Note: The he adds Person objects but he never looks at what is in the People Array except to print out the XML
Fast-forward (do people still know that this means?) to the present. I now need to look inside the People class and do something like this:
var people:People = ... init and fill with Person objects
for(var i:int=0; i<people.length(); i++){
doSomething(people[i]); // <-- Error thrown here.
}
Unfortionatly this throws this error:
ReferenceError: Error #1069: Property 0 not found on model.People and there is no default value.
at runner::Runner$/newUse()
at ExtendsArray/start()
at ExtendsArray/___ExtendsArray_Application1_initialize()
at flash.events::EventDispatcher/dispatchEventFunction()
What should I do?
Edit, Aside: Extending Array is not my doing this is part of our old model. We are moving away from the old model because it is full of garbage like this. I just need to grab this stuff from the old model to convert it into the new model. I would like to tear this code out of our product but the cost of doing that is probably not warranted.
What should I do?
Use only class methods to access and set items in your "array", don't use Array-specific syntax. And/or make the class dynamic.
EDIT I think you can leave everything as is and avoid making your class dynamic by defining only one additional method for item access (if it's not there for some reason). Something like:
public functon getItem(index:uint):*
{
if (index >= length) {
return null;
}
return this.slice(index, index+1)[0];
// this creates a redundant array on the fly, sorry.
}
// usage:
var people:People = ... init and fill with Person objects
for(var i:int=0; i<people.length(); i++){
doSomething(people.getItem(i));
}
And I know that is not the way it's meant to be answered on stackoverwlow, but... I can't hold it. ))
Anything extends Array -- is a heresy. If I see that in production code, I'll immediatelly proceed to initiating a "purge the unclean" sequence.
Just try googling for the subject a little bit, and you will see, that almost no one has got alive and well from an activitiy like that.
The main rational reason why this abomination is not meant to exist (aside form it being a heresy) is that you can not use array access [], you can not instantiate it like a normal array with items and you can not set items through array syntax [] and be notified of the changes somewhere in your class. But it is an Array by the right of birth, so any of your fellow developers not familiar with the subject may try to use it like a normal Array, because it's quite natural. And then they'll probably post another question on stackoverflow.
So, if you are still limited to just using class methods, what's the point in extending anyway? Whay not use neat aggregation/composition or proxy ways?
It's amazing, but there's even an article on extending Array on adobe.com. What they do not mention there is that you are likely to start burning in hell right away.
Array.length is a getter: it returns an int. people.length() is the same as calling 3(). I don't know how it worked when you tested that.
It looks like you'd be better off implementing something like IList and have addItem push into a Vector.<Person>. That will guarantee that you only have Person objects.
You should probably should not be extending Array. If you want to extend anything, extend Proxy (You can even use the ProxyArray class example with a Vector.<Person>). Extending top level classes (with the exception of Object) is often an invitation for confusion.
If you really, really want to extend Array, you have to make the class dynamic -- you are arbitrarily assigning and removing properties.
This looks like it works:
var s:String = "";
for each(var per:Person in people){
s += per.name + " ";
}
The People class has to be scripted as public dynamic class since it is extending the Array class.
From this Adobe help article: A subclass of Array should use the dynamic attribute, just as the Array class does. Otherwise, your subclass will not function properly.
You used the "push" function which apparently created an associative array.
Associative arrays can not be called by index. They can also not be reversed or have their order changed.
You need to access them by using the for..in loop
for (var key:String in people) {
trace("person : " + (people[key] as person).name);
}
// or as you found out the for each.. in
for each(var person:Person in people){
trace("person : " + person.name);
}
The arr.length() function of an associative array will always be 0 and you saw that with your error.
//Try this example you will see how an array can act like an array as we know it and an object.
var a:Array = [];
a[0] = true;
a.push(true);
a.push(true);
a["foo"] = true;
a.push(true);
a.push(true);
a.bar = true;
trace("for loop\n");
for(var i:int = 0, ilen:int = a.length ; i < ilen ; i++){
trace(i,a[int(i)]);
}
trace("\nfor...in loop\n");
for(var key:String in a){
trace(key,a[key]);
}