# 2014 03 15

## Version 2.0.6

## Simplified Event handling code. 

The callback function for event handling now only takes 1 single
parameter, the event which triggered the callback. The listener object
is bound to the callback function so within the callback function
`this` refers to the listener object. Unregistering listeners has also
been greatly simplified.  You can have an event handler which fires
only once by unregistering itself within the callback like this...

    events.on('player.PlayerJoinEvent', function( event ) { 

       // do something
       event.player.sendMessage( "You're the first player to join" );

       // unregister so this function is called only once ever.
       this.unregister();

    });

The `events.on()` function also returns the same listener object as
`this` refered to inside the callback. The listener object has a
single method `unregister()` which can be called to stop listening for
the event.

# 2014 03 12

Added Drone.MAX_VOLUME and Drone.MAX_SIDE properties to specify limits on size of Drone ops.
This is to stop individual players from hogging the CPU in a classrom environment.

# 2014 03 08

Fixed issues #115 #122 #123

Improved background processing of Drone build commands.

# 2014 02 19

## Version 2.0.5 

Asynchronous building. Drone now builds asynchronously. 
Fixed Issue #119 (exceptions on reload/stop)

# 2014 02 11

## Version 2.0.4

Various bug fixes, enhanced classroom module and improved error logging on startup.

# 2014 01 17

Added support for communication with Arduino and other devices which
use the [MQTT protocol][mqtt] via a new `sc-mqtt` module. This module
requires a separate sc-mqtt.jar file downloadable from
<http://scriptcraftjs.org/download/extras/mqtt> which must be included
in the CraftBukkit classpath. If using MQTT in ScriptCraft, then
Craftbukkit should be launched like this...

    java -classpath craftbukkit.jar;sc-mqtt.jar org.bukkit.craftbukkit.Main

You can use the new `sc-mqtt` module like this to send and receive
messages between minecraft and an Arduino. For example to send a
message to the MQTT broker whenever a player breaks a block...

    var mqtt = require('sc-mqtt');
    var client = mqtt.client('tcp://localhost:1883','scripcraft');
    client.connect();
    
    events.on('block.BlockBreakEvent', function(listener, event){
        client.publish('minecraft','block-broken');
    });

To have minecraft react to inputs from an MQTT broker...

    var mqtt = require('sc-mqtt');
    var client = mqtt.client('tcp://localhost:1883','scripcraft');
    client.connect();
    client.onMessageArrived(function(topic, message){
        var payload = message.payload;
        if (topic == 'arduino'){
           // do something with payload.
        }
    });    

[mqtt]: http://mqtt.org/
# 2014 01 14

Added config.yml file for configuration options. This file allows
scriptcraft admins to turn on or off re-unzipping of the modules,
plugins and lib folders when deploying a new version of
scriptcraft. It's strongly recommended that the lib directory always
be set to true to get the latest core scriptcraft code . The modules
and plugins directories are optional and not part of scriptcraft core.
The config.yml file looks like this...

    extract-js:
      plugins: true
      modules: true
      lib: true

# 2014 01 13

Bug Fix: Make ScriptCraft work with Nashorn javascript engine bundled with Java 8
<https://github.com/walterhiggins/ScriptCraft/issues/112>

# 2014 01 12

## Important
The ScriptCraft.jar file has been renamed scriptcraft.jar (see bug fix
details below). This means that you will have to remove the existing
`plugins/ScriptCraft.jar` file if present.

Bug Fix: On Mac OS, the plugins/scriptcraft directory is copied to
plugins/ScriptCraftPlugin the 2nd time ScriptCraftPlugin is loaded.
This has been fixed by changing the plugin name from ScriptCraftPlugin
to scriptcraft.  The jar file has also been rename from
ScriptCraft.jar to scriptcraft.jar.

New command: `jsp spawn` lets in-game operators spawn any type of
entity. For example `/jsp spawn cow` will spawn a cow at the in-game
operator's current location.

New minigame: Cow Clicker. A simple demonstration of using Bukkit's
Scoreboard API. Players click cows to score points. Scores are
displayed in a side bar on screen. Players join or leave the game by
typing `/jsp cowclicker` at the in-game prompt.

# 2014 01 05

Bug Fix: On Mac OS, alias plugin caused Exceptions due to missing
.trim() function on String.

Changed target for compilation to 1.6 so that ScriptCraft will work
with both java 1.6 and 1.7.

Added documentation for the Signs module.

# 2014 01 02

Added a warning in console at start-up if legacy directories are detected.
Added 'use strict' to core modules.
Bug Fix; Signs were not being saved. (introduced with recent change to JSONifying Location)

# 2014 01 01

'Buddha' Release - towards a total annihilation of the 'self' variable.
The 'self' variable should only be used at the in-game or server
console command prompts and should not be used in modules or in
multi-threaded code.

Moved scriptcraft directory from {craftbukkit-root}/scriptcraft to
{craftbukkit-root}/plugins/scriptcraft because this seems to be where
other plugins create plugin-specific directories on the filesystem.

Documentation updates. Added new sections to the Young Persons Guide
to Modding Minecraft.

# 2013 12 30

Removing coffeescript support because coffeescript.js will not
compile/evaluate (generated bytecode exceeds 64K limit).

Updated plugin to remove `self` variable once the `js` command
evaluation has completed (limits the scope of the `self` variable to
just command-prompt evaluation).

# 2013 12 29

Bug Fix: [Can't get Scriptcraft core libraries working][bug103].

[bug103]: https://github.com/walterhiggins/ScriptCraft/issues/103

Bug Fix; Server console errors when empty commands submitted.

Added more example modules.

# 2013 12 28

Documented the 'homes' module other tweaks to documentation.

# 2013 12 27

## Updated 'jsp alias' command.

The 'jsp alias' command now lets players define their own shortcuts
which don't require the 'jsp ' prefix.

### Example

At the in-game prompt use the following command to create a new alias
`cw` (short for change Clock & Weather) which will change the time and
weather using a single statement.

    /jsp alias set cw = time set {1} ; weather {2}

This creates a new cw alias which takes 2 parameters, time and weather
and passes them to the 'time set' and 'weather' commands. You use the
alias like this...

    /cw 4000 sun

... which in turn gets converted into these 2 commands...

    /time set 4000
    /weather sun

Aliases can be set on a per-player basis or can be set globally (for
all players). Aliases are automatically saved and restore on server
shutdown/startup.
    
## Added console global variable.

ScriptCraft now has a `console` global variable which can be used for
logging (to the server console). The `console` variable uses the
ScriptCraft plugin Logger object. You use the console object in your
javascript modules like this...

    console.info('Hello %s, %s', 'World', 'Universe');

... or simply...

    console.warn('Hello World');

# 2013 12 26

Made the `events` variable global because it is use by modules and
plugins. This means there is no longer any need to explicitly
`require('events')` since `events` is now a free variable in the
global namespace.

# 2013 12 25

Added the 'commando' module.

# 2013 12 24

## 'Modules' release

### Modules in ScriptCraft

ScriptCraft now has a simple module loading system. ScriptCraft now
uses the [CommonJS module contract][cjsmod] - that is - the same
module system used by Node.js. All of the javascript code which comes
bundled with ScriptCraft has been modified so that it conforms to the
CommonJS module system.

### What this means for plugins you've developed using ScriptCraft

If you have written plugins using a previous version of ScriptCraft then you have 2 options...

 1. Continue using the previous version of ScriptCraft.
 2. Update your plugins to work with the ScriptCraft 'Modules' release.

... Option 2 should be relatively straightforward if you follow these steps...

 1. Copy your own custom plugins from the `js-plugins` directory to the new `scriptcraft/plugins` directory.
 2. In your javascript code any functions, objects or variables which
    you want to expose for use by others should be exposed using the
    special `exports` variable. All other code within your .js files will
    now be private by default. See below for details on how
    CommonJS/Node.js modules work.

If you have any questions or concerns or need help converting your
existing javascript plugin, contact please post questions on the
[ScriptCraft forum][scforum] or open an issue on the [Github
project][github]

[github]: http://github.com/walterhiggins/ScriptCraft
[scforum]: https://groups.google.com/forum/?fromgroups=#!forum/scriptcraft---scripting-minecraft 

In ScriptCraft, files and modules are in one-to-one correspondence. As
an example, foo.js loads the module circle.js in the same directory.
*ScriptCraft now uses the same module system as Node.js - see [Node.js
Modules][njsmod] for more details.*

[njsmod]: http://nodejs.org/api/modules.html
[cjsmod]: http://wiki.commonjs.org/wiki/Modules/1.1.1

The contents of foo.js:

    var circle = require('./circle.js');
    echo( 'The area of a circle of radius 4 is '
               + circle.area(4));

The contents of circle.js:

    var PI = Math.PI;
    
    exports.area = function (r) {
      return PI * r * r;
    };

    exports.circumference = function (r) {
      return 2 * PI * r;
    };

The module circle.js has exported the functions area() and
circumference(). To add functions and objects to the root of your
module, you can add them to the special exports object.

Variables local to the module will be private, as though the module
was wrapped in a function. In this example the variable PI is private
to circle.js.

If you want the root of your module's export to be a function (such as
a constructor) or if you want to export a complete object in one
assignment instead of building it one property at a time, assign it to
module.exports instead of exports.

#### Module Loading

When the ScriptCraft Java plugin is first installed, a new
subdirectory is created in the craftbukkit directory. If your
craftbukkit directory is called 'craftbukkit' then the new
subdirectories will be ...

 * craftbukkit/scriptcraft/
 * craftbukkit/scriptcraft/plugins
 * craftbukkit/scriptcraft/modules
 * craftbukkit/scriptcraft/lib

... The `plugins`, `modules` and `lib` directories each serve a different purpose.

##### The plugins directory

At server startup the ScriptCraft Java plugin is loaded and begins
automatically loading and executing all of the modules (javascript
files with the extension `.js`) it finds in the `scriptcraft/plugins`
directory. All modules in the plugins directory are automatically
loaded into the `global` namespace. What this means is that anything a
module in the `plugins` directory exports becomes a global
variable. For example, if you have a module greeting.js in the plugins
directory....

    exports.greet = function() {
        echo('Hello ' + self.name);
    };

... then `greet` becomes a global function and can be used at the
in-game (or server) command prompt like so...

    /js greet()

... This differs from how modules (in NodeJS and commonJS
environments) normally work. If you want your module to be exported
globally, put it in the `plugins` directory. If you don't want your
module to be exported globally but only want it to be used by other
modules, then put it in the `modules` directory instead. If you've
used previous versions of ScriptCraft and have put your custom
javascript modules in the `js-plugins` directory, then put them in the
`scriptcraft/plugins` directory. To summarise, modules in this directory are ...

 * Automatically loaded and run at server startup.
 * Anything exported by modules becomes a global variable.

##### The modules directory

The module directory is where you should place your modules if you
don't want to export globally. In javascript, it's considered best
practice not to have too many global variables, so if you want to
develop modules for others to use, or want to develop more complex
mods then your modules should be placed in the `modules` directory.
*Modules in the `modules` directory are not automatically loaded at
startup*, instead, they are loaded and used by other modules/plugins
using the standard `require()` function.  This is the key difference
between modules in the `plugins` directory and modules in the
`modules` directory. Modules in the `plugins` directory are
automatically loaded and exported in to the global namespace at server
startup, modules in the `modules` directory are not.

##### The lib directory

Modules in the `lib` directory are for use by ScriptCraft and some
core functions for use by module and plugin developers are also
provided. The `lib` directory is for internal use by ScriptCraft.
Modules in this directory are not automatically loaded nor are they
globally exported.
