rpgmaker-plugin-dev

Plugin development

Tools

list_plugins, read_plugin, create_plugin (scaffold), write_plugin (replace the source), configure_plugin (set parameters, enable/disable), add_plugin / remove_plugin (register in js/plugins.js), then playtest_start and playtest_log to see console errors (NW.js mode).

File header

The editor reads parameters from a comment block at the top of the file:

//=============================================================================
// MyPlugin.js
//=============================================================================
/*:
 * @plugindesc One line shown in the plugin manager.
 * @author Name
 *
 * @param Speed
 * @desc What this parameter does.
 * @default 4
 *
 * @help
 * Describe plugin commands and usage here.
 */

The file name and the registered plugin name must match exactly. Plugin parameters are strings: convert with Number(...) or JSON.parse.

Pattern for changing engine behaviour

Never edit js/rpg_*.js. Alias the original method and call it:

(function() {
  var params = PluginManager.parameters('MyPlugin');
  var speed = Number(params['Speed'] || 4);

  var _Game_Player_initialize = Game_Player.prototype.initialize;
  Game_Player.prototype.initialize = function() {
    _Game_Player_initialize.call(this);
    this.setMoveSpeed(speed);
  };
})();

Always wrap code in an IIFE, keep aliases in local variables and call the original unless you intend to replace it.

Plugin commands

var _Game_Interpreter_pluginCommand = Game_Interpreter.prototype.pluginCommand;
Game_Interpreter.prototype.pluginCommand = function(command, args) {
  _Game_Interpreter_pluginCommand.call(this, command, args);
  if (command === 'MyCommand') { /* args are the space-separated words */ }
};

Events call it with event command 356: parameters: ["MyCommand arg1 arg2"].

Order and testing

• Plugin order matters: plugins that alias the same method wrap each other in load order. list_plugins shows the order.
• After writing, playtest_start in NW.js mode and read playtest_log for ReferenceError/TypeError. A black screen at startup is almost always a plugin error.
• Use configure_plugin for parameters instead of editing js/plugins.js by hand.
• MV runs in NW.js with its own JavaScript engine version: avoid syntax newer than the project's runtime supports unless you have verified it.