Tutorial Instructions
In the AS2 version of load variables it was a little more confusing on how to retrieve variables
from an outside resource such as a text file or a webpage. The new AS3 way is much simpler in
the retrieval of variables but you have to implement a few things before we can get to the
actual retrieval part.
Step 1: Create the data file
In the first part of this tutorial we are going to create a data file called data.txt where
we will put the variables to be loaded into the movie. So create the file data.txt and save
it in the same folder as your .fla file is saved in. We will put the following code into the text
file:
var1=name&var2=number&var3=1922&var4=14567
You will notice how we created four different variables: var1, var2, var3,
and var4. It is important to notice that each variable must end with an & at the end to
denote when we are starting a new variable.
Step 2: Create the .fla file
What we are going to do is create 4 dynamic texts to show the variables once they are loaded into
the movie. We will also create 4 labels so it kind of looks something like this:
We will name instance variables of the dynamic texts as such. Name the first one variable1, the second
one variable2, the third one variable3, and the last one variable4.
Step 3: Add the code to the frame
Alright so we need to do a few things here. We need to setup a loader where we can call the file
and load it in. We also have to set the parameter of the loader to variables since that is what
we are retrieving. So first add the following code:
// Need to create a URL Loader called loader
var loader:URLLoader = new URLLoader();
// specify what we are loading, in this case variables
loader.dataFormat = URLLoaderDataFormat.VARIABLES;
The first part of the code creates a URLLoader which will let us load the data from a designated
url that we will add in a second. The second part designates the dataFormat which we chose to set
as VARIABLES because that is what we will be retrieving. It would change, for example, if we decided
to load an image.
Now we need to add an event listener to call a function after the URL is loaded. The following code
shows us how to do that:
// add an event listener to do the function when done loading
loader.addEventListener(Event.COMPLETE, varsLoaded);
The event listener will let us call the function varsLoaded on the completion of the laoder
loading in the URL. Now we need to go ahead and load a URL with the following code:
// actually call the loader to load the file
loader.load(new URLRequest("data.txt"));
Now you see that we called load with a new URLRequest with the link of the location of the file we
created data.txt. The URL is simple just "data.txt" because we kept it in the same folder
as the movie.
Now the last part of the code we need to add is the function to set the dynamic texts we created in
the second part of the tutorial. The function we know is already called varsLoaded as defined by
the event listener we added. So lets create the function:
// set the variables from the data.txt file
function varsLoaded (event:Event):void {
variable1.text = loader.data.var1;
variable2.text = loader.data.var2;
variable3.text = loader.data.var3;
variable4.text = loader.data.var4;
}
You will notice that the parameters is the event and the function is void because it returns no
data, just sets the dynamic texts. So we set the dynamic texts with variable1.text=. We
set the variable to the laoder.data.var1. We call var1, because that is what we named it in the
data.txt file.
That should complete the tutorial. Your final result when testing should look like this:
Complete Source Code and Download
Here is the complete source code and a download for the source files:
// Need to create a URL Loader called loader
var loader:URLLoader = new URLLoader();
// specify what we are loading, in this case variables
loader.dataFormat = URLLoaderDataFormat.VARIABLES;
// add an event listener to do the function when done loading
loader.addEventListener(Event.COMPLETE, varsLoaded);
// actually call the loader to load the file
loader.load(new URLRequest("data.txt"));
// set the variables from the data.txt file
function varsLoaded (event:Event):void {
variable1.text = loader.data.var1;
variable2.text = loader.data.var2;
variable3.text = loader.data.var3;
variable4.text = loader.data.var4;
}
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