This is a hello world example which will be compiled and linked to Emscripten.

Setup

• OS Windows 7 x64 (I have not tested on Mac or Linux).
• Haxe version 4+
• Emscripten emsdk lastest version

Implementation

1. Install emsdk.zip.
2. Update it to latest version and activate it to the latest version.

Create a simple Hello World Haxe code:

Main.hx

package;

@:buildXml("
  <linker id='exe' exe='em++'>
    <flag value='-s' />
    <flag value='WASM=1' />
  </linker>
")

class Main {
  static function main(){
    trace("Haxe is great!");
  }
}

build.hxml

# Windows maybe needs this define
-D EMSCRIPTEN_SDK

# If you want the .html file showing how to embed the wasm
-D HXCPP_LINK_EMSCRIPTEN_EXT=.html

# Tell hxcpp to use emscripten-toolchain.xml
-D emscripten

-cpp out
-main Main

The link and build.hxml is based on https://groups.google.com/forum/#!topic/haxelang/Pcm38LPFjW0

It will then link "main.html".

Open main.html in your browser to run it.

Troubleshooting

Problem: Unable to find the full path for emcc.
Possible Solution:
The problem was traced to the variable EMSCRIPTEN_SDK, in the emscripten-toolchain.xml. Found in the "\HaxeToolkit\haxe\lib\hxcpp\4,0,19\toolchain" folder. When the EMSCRIPTEN_SDK, is set to the correct path for 'emcc'. The script still unable to find the full path to 'emcc'.

The best option is to hard code the full path name in the emscripten-toolchain.

Change from:

<section if="windows_host">
   <set name="HXCPP_RANLIB" value='python "${EMSCRIPTEN_SDK}/emranlib"' />
   <set name="HXCPP_AR" value='python "${EMSCRIPTEN_SDK}/emar"' />
   <set name="CXX" value='python "${EMSCRIPTEN_SDK}/emcc"' />
</section>

To:

<section if="windows_host">
   <set name="HXCPP_RANLIB" value='python "c:\emsdk\fastcomp\emscripten/emranlib"' />
   <set name="HXCPP_AR" value='python "c:\emsdk\fastcomp\emscripten/emar"' />
   <set name="CXX" value='python "c:\emsdk\fastcomp\emscripten/emcc"' />
</section>

With the above solution you will only need to install the latest version of emsdk.