From 82c9b9c1255e40502f4fa428f09c39d08a607f7c Mon Sep 17 00:00:00 2001 From: walterhiggins Date: Tue, 24 Dec 2013 23:07:20 +0000 Subject: [PATCH] release notes for 'modules' release --- docs/release-notes.md | 132 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 docs/release-notes.md diff --git a/docs/release-notes.md b/docs/release-notes.md new file mode 100644 index 0000000..11de0e6 --- /dev/null +++ b/docs/release-notes.md @@ -0,0 +1,132 @@ + +# 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.