NodeLua
======

NodeLua is a module to expose Lua bindings to Node.JS.

This is still a work in progress, collaborators welcome.

## Install
Lua and it's C libraries are required for this module to work.

```bash
npm install nodelua
```

```javascript
var nodelua = require('nodelua');
```

## API
### NodeLua
The `NodeLua` module itself only contains a single Object `LuaObject`.
```javascript
var lua = new nodelua.LuaObject()
```

### LuaObject
The `LuaObject` is an object wrapper around a `lua_State` instance.

#### doFile(file_name)
The `doFile` method is used to load and execute lua code stored in `file_name`.
```javascript
lua.doFile('test.lua');
```

### doString(lua_code)
The `doString` method is the same as `doFile` except the code is loaded from `lua_code` rather than from a file.
```javascript
lua.doString("print('Hello, Lua')");
```

### setGlobal(name, value)
The `setGlobal` method is used to provide lua with the global variable `name` containing the value `value`.
```javascript
lua.setGlobal('test', 'value');
```

### getGlobal(name)
The `getGlobal` method is used to retrieve either a value set by `setGlobal` or a global variable in any lua code that has been run.
```javascript
console.log(lua.getGlobal('test'));
```

### registerFunction(name, func)
`registerFunction` is used to expose a javascript function `func` to lua with the name `name`.
```javascript
lua.registerFunction('add_them', function(a, b){
  console.log(a+b);
});
```
There are a few caveats with `registerFunction`.

For starters in order to invoke the javascript function from within lua you must use an exposed `nodelua` function as opposed to using the functions registered `name`.
```lua
nodelua('add_them', 3, 5)
```

As well, there are problems with using `registerFunction` with multiple `LuaObjects`, you will probably end up with a `Segmentation fault: 11` error when running the code. I am working on this issue.

### close()
`close` should be used whenever you have finished using a `LuaObject`. This will simply call `lua_close` on the `lua_State` for that object.


## Example
See test/test.js

```javascript
var nodelua = require('nodelua');
var lua = new nodelua.LuaObject();

lua.registerFunction('add_them', function(a, b){
  console.dir(a+b);
});

lua.doFile('some_file.lua');
console.dir(lua.getGlobal('some_var'));

lua.close()
```

## TODO
 * Currently there are issues with having multiple `LuaObjects`, this is my next task.
 * I want to expose the stack functions from lua so it is easy to pop/push objects to lua.

## License
The MIT License (MIT)
Copyright (c) 2012 Brett Langdon <brett@blangdon.com>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.