Javascript Wrapper¶

Pre-Compiled Binaries¶

Download the precompiled binaries from Javascript, or the development versions from the buildbot server at Javascript. Remember to get both files, coolprop.js and coolprop.wasm.
You can load your js file into your website, following the structure of the example here, which is also included at the above download.
Alternatively, you can link to our server directly to make sure that you always have the latest version of CoolProp. To do so, include the address <script src="http://www.coolprop.sourceforge.net/jscript/coolprop.js"></script> in your HTML header instead of the relative path <script src="coolprop.js"></script>.
A live demo of the Javascript library in action can also be found online.

Serving the JS¶

The .wasm file can cause some problems for hosting emscripten-compiled JS files. When locally hosting, you need to ensure that the .wasm file extension is served with MIME type application/wasm. A simple webserver config in Python 3 for testing CoolProp (with proper hosting of the WASM) could read:

import http.server
from http.server import BaseHTTPRequestHandler, HTTPServer

port=8000
print("Running on port %d" % port)

http.server.SimpleHTTPRequestHandler.extensions_map['.wasm'] = 'application/wasm'
httpd = HTTPServer(('localhost', port), http.server.SimpleHTTPRequestHandler)

print("Mapping \".wasm\" to \"%s\"" %
http.server.SimpleHTTPRequestHandler.extensions_map['.wasm'])
httpd.serve_forever()

On Apache, you need to setup the server appropriately.

User-Compiled Binaries¶

Docker¶

We run the emscripten-based builds in a docker container and you can follow the CI example here, which is also the script that generates the official downloads.

Linux (deprecated)¶

We are following the instructions from emscripten.org - download the portable emscripten SDK emsdk for linux.

First download node.js, clang++ and llvm using:

sudo apt-get install nodejs clang++ llvm

Expand the SDK zip file linked above

At the console in the folder that contains the file emsdk run the commands:

emsdk update # This will fetch the list of things to download

emsdk install latest # This will download and install the full toolchain

Go enjoy a nice walk or a cup of coffee - it will be a while

Activate the SDK just compiled:

emsdk activate latest # This will make the file ~/.emscripten with the paths to most of the binaries compiled in SDK

Modify the file ~/.emscripten to make NODE_JS path equal to which nodejs if it doesn’t already
Make an environmental variable (in ~/.profile) export EMSCRIPTEN=/path/to/emsdk that points to the folder that contains emc++, emcc, etc.

Check out coolprop:

git clone https://github.com/CoolProp/CoolProp --recursive

Folder creating:
```
mkdir -p build && cd build
```

Build the Javascript module:

cmake .. -DCOOLPROP_JAVASCRIPT_MODULE=ON -DCMAKE_TOOLCHAIN_FILE=${EMSCRIPTEN}/cmake/Modules/Platform/Emscripten.cmake

Windows (deprecated)¶

Download the EMSDK installer, run the web download installer, that will install everything, and get you ready.

In the %HOME%/.emscripten file, make sure that there is only one entry for NODE_JS and it points to the right place. Mine looks like:

import os
SPIDERMONKEY_ENGINE = ''
LLVM_ROOT='C:/Program Files/Emscripten/clang/e1.21.0_64bit'
NODE_JS='C:/Program Files/Emscripten/node/0.10.17_64bit/node.exe'
PYTHON='C:/Program Files/Emscripten/python/2.7.5.3_64bit/python.exe'
EMSDK_GIT='C:/Program Files/Emscripten/git/1.8.3'
EMSCRIPTEN_ROOT='C:/Program Files/Emscripten/emscripten/1.21.0'
V8_ENGINE = ''
TEMP_DIR = 'c:/users/belli/appdata/local/temp'
COMPILER_ENGINE = NODE_JS
JS_ENGINES = [NODE_JS]

Open an Emscripten command Prompt (Start->Emscripten->Emscripten command Prompt)
Make an environmental variable EMSCRIPTEN that points to the folder that contains emc++, emcc, etc.
Navigate to the root of the source
Build the build folder:
```
mkdir build && cd build
```

Build the Javascript module:

cmake ../.. -DCOOLPROP_JAVASCRIPT_MODULE=ON -DCMAKE_TOOLCHAIN_FILE=%EMSCRIPTEN%/cmake/Modules/Platform/Emscripten.cmake