AS3 scripting at runtime

htmiel

A quick test with the following script:

var X = 0;
function doSomething()
{
    X = X + 2;
    X = X - 1;
    if(X % 5 == 0)
    {
        X = X*2;
    }
}

and calling the "scripted" doSomething() function from "native" AS3 code 10.000 times, took only 92ms. (and this was running in the debugger)

2dguy

yah..I was going to suggest to just write your run time interpreter. You can make up your own language/parser, etc, and do whatever you want. This way you have much better control of the code, security, etc. I did something similar years ago. It's much easier than you would think.

htmiel

At the moment I found this library, I was actually thinking to start writing my own. But this library is absolutely perfect for my needs.

Many thanks for the authors of it: Yoshihiro Shindo, Sean Givan, and anyone else who contributed to it, and released it under such a permissive license.

Dimensionscape

You dont need to write an interpreter to do this. You can create an swf on the fly from text by invoking xmxlc in your project and then load the swf/actionscript. Just distribute the open source xmxlc with your project.

JohnBlackburne

That has all sorts of problems with it. You can’t just bundle developer tools with a project, such as a game you are going to distribute through e.g. Steam. First there’s licensing it, as mxmlc is not free, it’s part of the AIR SDK from Adobe. You also need to include Java which few people will have installed, and is also not free. Then there’s ensuring it works, including when e.g. your app does not have write access to its folders.

And it simply won’t work on Android or iOS, for which there are no tools, and even if there were Apple expressly forbid anything like this, and I think Google are going the same way.

Dimensionscape

JohnBlackburne The open source Apache Flex SDK has mxmlc(https://github.com/apache/flex-sdk) and is released with their license. I am not suggesting packing anything with the publishing tools/adl from Adobe. The original poster didnt mention anything about doing anything on mobile and you can easily check if Java is installed and direct the user to install it... I don't see any problems.

htmiel

Thank you for your suggestion. I tried to Google for "xmxlc" but can't find any information on it.

Anyway, even if it worked, and even if it did not break any Apple rules, the fact that it "creates a swf" is not pretty useful to me, because I need to execute these scripts purely from AS3 code classes, without loading any external files.

JohnBlackburne

I think xmxlc is a typo. The compiler is mxmlc, and it’s part of the AIR SDK.

JohnBlackburne

Dimensionscape the Apache Flex SDK does not include mxmlc. mxmlc is part of the AIR SDK which you need to obtain from Adobe. Adobe stopped work on the Flex SDK and handed it to Apache, but not the AIR SDK.

Dimensionscape

On mobile you could connect to a remote server that creates the swf and returns it as a byte array to load. I don't know if this violates apple's policy or not but easily doable.

Side note, is there a way to edit posts? Yes Xmxlc was a typo. Dyslexic moment.

htmiel

Sorry for my omission, indeed what I'm doing is intended to run on iOS.

And form what I know, there is no way to run "swf" files on iOS (even if I could download them from a server). When the iOS app is build, all swf files in the project get stripped of all code, and all the code gets converted into native code.

There is no actual "flash runtime" when the Air app runs on iOS to interpret swf files.

Dimensionscape

@htmiel you dont actually run an swf file. You can script everything to happen in the background. The compiler allows you to build classes into SWF which you can load and execute on the fly inside an AIR app. You would design your software to save text as .as and then call mxmcl passed with the .as file that was just made. Check for the successful creation of the SWF and then load it. You can do all of this pretty seamlessly with a few lines of code. Likewise, you can build a simple server that handles the requests and returns your swf as a bytearray. The actual swf doesnt even have to exist on your device in this case as its created by the server and sent as bytes(possibly encrypted, I would suggest). Your code should convert it (after decrypting if that layer of security was added for a server based scenario) from a byte array back into swf in memory and then load it internally.

I'm not sure if you're understanding me 100%. It really is a quite simple...I could build you an example if you'd like.

musanss

Dimensionscape I need help on that

htmiel

This article:
http://blogs.adobe.com/airodynamics/2012/11/09/packaging-and-loading-multiple-swfs-in-air-apps-on-ios/

clearly states that you cannot run external swf files:

Any attempt to load a SWF (local or remote) dynamically that contains ActionScript byte code (or ABC) using either Loader.load() or Loader.loadBytes, resulted in an “Uncompiled ActionScript” error.

I have already started to implement the BISE Scripting Engine, it's easy, straightforward, fast, written 100% in AS3, and does everything I need.

Thanks @Dimensionscape for the suggestions, but at least for my requirements, mxmlc is not a good fit.

Dimensionscape

htmiel I admittedly don't know a whole lot about the quirks of running on iOS. Just putting the info out there for other people who search and wander upon this thread. Good luck with your project. 🙂

htmiel

Thanks! Good luck to you too.

joshtynjala

JohnBlackburne Apache Flex SDK does not include mxmlc

The Apache Flex SDK actually does include a fully open source ActionScript and MXML compiler that produces SWFs, and it is called mxmlc. It is the same compiler that was available in the original Adobe Flex SDK.

You might be thinking of adt, which is used to package Adobe AIR apps.

Or maybe you're thinking of the ASC 2.0 compiler in the AIR SDK, which is also called "mxmlc". That one is not open source. Well, technically, a fork of it is actually open source in Apache Royale, but the Royale version has not necessarily remained in sync with Adobe's version.

Dimensionscape

JohnBlackburne https://github.com/apache/flex-sdk/blob/master/bin/mxmlc I'm sorry but you're wrong.

I also want to note, for future readers, that a later version of the SDK allows external swf with actionscript on iOS. http://blogs.adobe.com/airodynamics/2013/03/08/external-hosting-of-secondary-swfs-for-air-apps-on-ios/ I'm still not sure whether it will still work on iOS or not. Going to test it later on...

htmiel

@Dimensionscape from the last link you provided:

The developer needs to provide the url of the secondary stripped SWF in the URLRequest.

To use this feature, developer needs to specify a text file containing details of the SWF files to be stripped & externally hosted.

During IPA packaging, ADT extracts the ABC code from all child SWFs, adds it to the final executable and generates stripped SWFs in the “externalStrippedSwfs” folder created in the current working directory.

The "externally hosted swf files" actually have no code, and that code has to be already compiled in the main application.

JohnBlackburne

That’s just a shell wrapper. The actual code is in mxmlc.jar – see the last line of it. And the Apache Flex SDK does not include mxmlc.jar, it’s part of the AIR SDK which you need to obtain from Apple. As it says in the readme:

Download the AIR SDK for your platform and unzip it. Set AIR_HOME to the
absolute path of the AIR SDK directory.

Dimensionscape

JohnBlackburne

The following dependencies have licenses which Apache considers to be
incompatible with the Apache License Version 2.0. You will be prompted to read
and agree to the license terms of the dependency before the software can be
downloaded to your system. These are optional components which enable
additional features. They are installed in libs/external/optional.
adt.jar, afe.jar, aglj40.jar, flex-fontkit.jar and rideau.jar (provide embedded font support)

These jars are extracted from:

    http://fpdownload.adobe.com/pub/flex/sdk/builds/flex4.6/flex_sdk_4.6.0.23201B.zip

and are released under an Adobe license:

    http://www.adobe.com/products/eulas/pdfs/adobe_flex_software_development_kit-combined-20110916_0930.pdf

joshtynjala

JohnBlackburne And the Apache Flex SDK does not include mxmlc.jar

Yes it does. I have literally contributed to the compiler source code in the Apache Flex SDK.

Everything for building a SWF file is open source and included in Apache Flex (well, except for some font embedding stuff). No wrappers. If you were targeting Flash Player and not Adobe AIR, you could use the Apache Flex SDK without adding the Adobe AIR SDK to it.

Dimensionscape

@joshtynjala Exactly. It has nothing to do with AIR particularly, its simply for compiling SWFs....

JohnBlackburne included right here.... https://github.com/apache/flex-sdk/blob/master/modules/compiler/src/java/flex2/tools/Mxmlc.java (source)

I have a massive project involving distribution of mxmcl as a dependency. I made sure it was licensed for me to do so months ago. I also take care to mention the open source mxmcl and not the one from the AIR SDK because they're different.

« Previous Page