Is dynamic variable naming like this possible in ActionScript 3?
for (var xz=0;xz<10;xz++){
var this['name' + xz]:Number = xz;
}
You should use an array for this kind of list of variables.
While you can create properties dynamically, you usually want to avoid it. Especially in your case, where the actual identifier of each variable is not a String, but a number. So why not use something that does exactly that: identify its elements by a number? And that's exactly what an array does.
code example:
var xzs:Array = [];
for (var xz:uint = 0; xz < 10; xz++){
xzs.push(xz);
}
Short answer is: no, you can't declare at runtime typed properties.
Long answer is: kinda.
If you want to create new typed properties you'll have to store them in a Vector<>.
Anything else would let you do it but untyped, dynamic class, store in object, store in array, etc ...
Yes, it sure is - AS3 comes from ECMA script, so this is setting a property to an object (in this case it's this). So you can dynamically set properties. But you are a little bit wrong about how to do it - there is no need to use var, because you don't declare it, you set it. It's like using:
this.propertyName = 'value';
From now on, this will have propertyName equal to 'value'. Therefore you should just use:
this['name' + xz] = xz;
That's all!
Edit: as BotMaster mentioned - if you are using classes and you want to dynamically add properties, the class must be set as dynamic. Most of the commonly used ones are already dynamic (as Aaron mentioned :)).
I didn't go into much details as I think you simply need to do this on your timeline. If not - please specify this in your question so that you can get more accurate answer than this one. The same goes if your new property needs to be typed (can't think of any point wanting this) - you should see BotMaster's answer :)
Related
for an application I am building an administration panel where a power user should be able to check the JSON structure of a selected object.
I would like to display the JSON object in a computed text field but display/format it nicely so it is better human readable, something similar as in pretty print.
Is there any function I could use in SSJS that results in something similar so I can use display json nicely in computed text / editable fields?
Use stringify's third parameter "space":
JSON.stringify(yourObject, null, ' ');
space
A String or Number object that's used to insert white
space into the output JSON string for readability purposes. If this is
a Number, it indicates the number of space characters to use as white
space; this number is capped at 10 if it's larger than that. Values
less than 1 indicate that no space should be used. If this is a
String, the string (or the first 10 characters of the string, if it's
longer than that) is used as white space. If this parameter is not
provided (or is null), no white space is used.
As XPages doesn't support JSON.stringify yet you can include JSON's definition as SSJS resource and use it.
As Knut points out, you can certainly add json2.js to XPages; I've previously used an implementation as Marky Roden's post outlines. This is probably the "safest" way of doing so, from the SSJS side of things.
It does ignore the included fromJson and toJson SSJS methods provided out of the box in XPages. While imperfect, they are functional, especially with the inclusion of Tommy Valand's fix snippet. Be advised, using Tommy's fix does wrap responses to ensure a proper JS object can be parsed by shoving an Array into an object with a values property for the array; so no direct pulling of an Array only.
Additionally, I believe it would be useful to point out that a bean, providing a convenience method or two as wrappers to use either the com.ibm.commons.util.io.json methods to abstract the conversion method, or switching in something like Google GSON, might be more powerful and unified, based on your style of development.
Knut, Eric, I came so far myself already.
function prettyPrint(id) {
var ugly = dojo.byId(id).value;
var obj = $.parseJSON( "[" + ugly + "]" );
var pretty = JSON.stringify(obj, undefined, 4);
dojo.byId(id).innerHTML = pretty;
}
and I call it e.g.
var name = x$('#{id:input-currentObjectCollectionFiltered}').attr("name");
prettyPrint(name);
I tried to make use the x$ function but was not able to make the ID dynamic there e.g.
var ugly = x$('#{id:" + id + "}').val();
not sure why. would be nicer if I just would call prettyPrint('input-currentObjectCollectionFiltered'); and the function would figure it out.
Instead of dojo.byId(id).value I tried:
var ugly=$("#" + id).val();
but things returns and undefined object: I thought jquery would be smarter to work with dynamic id's.
anyway stringify works just fine.
So, I need a button that would add a new ListElement to existing list. I need to fill in one value, taken from TextField. I have no idea how to do this. I tried something like
onClicked:{
nameOfList.append(JSON.parse([nameOfList.nameOfColumn,myTextField.text]));
}
Obviously it didn't work. Do I have to send these two values to C++, then make a QJsonObject and send it back, or is there an easier way?
While the question does not describe the type of nameOfList, I assume it is ListModel since the question is about adding a new ListElement. In that case, appending would be straightforward:
onClicked:{
nameOfList.append({"nameOfColumn": myTextField.text})}
}
However, if nameOfList.nameOfColumn is not constant, you'd need to make a temporary:
var temp = {}
temp[nameOfList.nameOfColumn] = myTextField.text
nameOfList.append(temp)
It can depend on what exactly nameOfList is, but here you will most probably find an answer.
So I've spent an embarrassing number of hours trying to save myself a few minutes and make my code a bit neater, and Google has produced nothing, so now I come crawling to stackoverflow. The problem is with square bracket notation + library items:
So let's say you have a MovieClip called "myMC_5", and you want to set its X position to 0..
myMC_5.x = 0;
..and if you don't want to hard-code the name of the MC but instead you want one line of code to move a specific MovieClip based on a variable, you could do something like this:
var selectMC = 5;
root["myMC_"+selectMC]x = 0;
..and this will have the exact same effect as myMC_5.x = 0, except that this time you must specify the location ("root" or "this" or something).
THE PROBLEM:
I'm working on a game in which the graphic for the background is loaded from the library, and it's different for each level. The initial loading of the vector from the library looks like this:
private var land:vector_land0 = new vector_land0();
..and this works fine, but it only loads that one specific vector. There should be about 30 or more. I'd like to just have 1 line of code in the constructor to load any of them, based on a variable which keeps track of the current level, like this:
private var land:["vector_land"+theLevel] = new ["vector_land"+theLevel]();
..but that doesn't work. I get syntax errors ("expecting identifier before leftbracket") because you need to specify the location of the object, like in the first example:
root["myMC_"+"whatever"].x = 0;
..but this library item has no "location". So, how the heck do I dynamically load a vector from the library? It's not "on the root", or anywhere else. It has no location. I refuse to believe that the standard method for accomplishing this is to create 30 different classes or write a giant block of code with 30 "if" statements, but searching Google has found nothing. :(
It sounds like you're looking for getDefinitionByName(), which you could use to do something like this:
import flash.utils.getDefinitionByName;
private var LevelVectorClass:Class = getDefinitionByName("vector_land" + theLevel) as Class;
private var land:Object = new LevelVectorClass();
This is a horrible way to solve the situation, I don't recommend using square brackets anywhere but arrays. I recommend you putting the "lands" into a LandContainer MovieClip, each frame of that MovieClip would container 1 graphic. It is much cleaner, and you could create constants to store the "identity" of the frames.Example:
var land:LandContainer = new LandContainer();
land.gotoAndStop(FIRST_LEVEL); //FIRST_LEVEL is a constant integer
You can even reuse this LandContainer instance because you can set it's visibility, remove from the display list, set it's frame to the next level without creating another instance. On second thought, I would write a wrapper for this class. Aka link it to your own class which extends the MovieClip class and create custom functions, fields... etc..
This dynamic thing is horrible, hard to maintain, and not efficient at all. Don't know why did not they delete it from AS3... they should have.
I need to add a drop down for selecting the minutes.I have tried through component parameters in FLA and through XML.When i gave the value 00,01..etc they are taken as 0,1.But i need 00,01..etc.
How it is possible.Thanks in advance.
I would assume that they're being treated as Numbers, my advice would be:
var numAsString:String = myNumber.toString();
if (numAsString.length<2) {numAsString = "0"+numAsString;}
That should force it to show in the format you want. Just be sure to use parseInt(numAsString) if you need to do any manipulation.
well i created some variables in the main stage level, with something like this:
for(i=0,i<10,i++){
var var_name="var_num_"+i;
this[var_name]="some value";
}//<-----------------------------------------------------works
so i get 10 variables named "var_num0", "var_num1", "var_num2" each one with some value.
and i can acces them any where calling this
var second_var=MovieClip(root).var_num0;//<--------------works
my problem comes when i want to call all the variables from a lower level or in another frame or somewhere else using another loop:
var third_var;
for(j=0,j<3,j++){
third_var=this["MovieClip(root).var_num_"+j];//<---------DOSNT WORK
trace(this["MovieClip(root).var_num_"+j]);//<------------returns "undefined"
}
how can i make this work? i tried a lot of things and nothing...
thanks you all
In your case both "root" and "this" are the scope you want to access the vars from. so try this:
var third_var:MovieClip;
for(j = 0; j < 3; j++)
{
third_var = MovieClip(root)[var_num_ + j];
trace(third_var);
}
Also you should have semi-colons in your for loop rather than comers.
I'd like to preface my answer with a suggestion you use a 'Document Class' with AS3 to make things like namespaces and inheritance much clearer. You know exactly where things are accessible when using document based, object oriented programming versus the timeline programming available through the Flash IDE (its only there because of AS1/2). Tut: http://www.kirupa.com/forum/showthread.php?223798-ActionScript-3-Tip-of-the-Day/page14
On to the answer: You are trying to move two levels of inheritance in one set of [] Another way of writing your first "Doesn't work" line is:
this.myMovieClip["var_num"+j"];
You could also use: this["MovieClip"]["var_num"+j];
Basically, you need to take the "MovieClip(root)" out of the string you are using to call your variable because you are passing through two levels of inheritance: this->MovieClip->targetVar
You need to use two periods, a period and a set square bracket or two sets square brackets to move two levels of inheritance. A period . and a set of square brackets [] both accomplish the task of moving one level deeper, so putting the . inside the string used to call up your variable won't work.
Explanation:
The following three examples all return the same variable:
myMovieClip.my_variable
myMovieClip["my_variable"]
var str:String = "my_variable";
myMovieClip[str];