Added onCreate to components

The entity is passed to onCreate, to be able to get the ID or other components in that entity
Added "get" to world, which returns an array of matching entities
Various refactoring, added an invoke function
Simplified every() method, got rid of "this" hacks by using "bind"
Updated to v0.2.6

package.json

@@ -1,6 +1,6 @@
 {
   "name": "picoes",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "Pico Entity System for JavaScript (ES6).",
   "main": "./src/picoes.js",
   "scripts": {

src/entity.js

@@ -1,3 +1,5 @@
+let invoke = require('./utilities.js').invoke
+
 // Entity class used internally for keeping track of components
 class Entity {
 	constructor(world, id) {
@@ -43,6 +45,9 @@ class Entity {
 		if (this.valid() && component in this.world.components) {
 			// Use defined component template
 			this.data[component] = new this.world.components[component](...args)
+
+			// Call custom onCreate with this entity as a parameter
+			invoke(this.data[component], 'onCreate', this)
 		} else if (args.length > 0) {
 			// Use first argument as component value
 			this.data[component] = args[0]
@@ -82,10 +87,9 @@ class Entity {
 				this.world.index.remove(this, component)
 			}
 
-			let comp = this.data[component]
-			if (typeof comp.onRemove === 'function') {
-				comp.onRemove()
-			}
+			// Call custom onRemove
+			invoke(this.data[component], 'onRemove')
+
 			delete this.data[component]
 		}
 		return this

src/picoes.js

@@ -1,3 +1,4 @@
+let invoke = require('./utilities.js').invoke
 let Entity = require('./entity.js').Entity
 let Index = require('./index.js').Index
 
@@ -78,8 +79,11 @@ class World {
 	// world.system(class { every(ent) {} })
 	system(components, systemClass, ...args) {
 		if (isFunction(systemClass)) {
+			// Create the system, and set the component array query
 			let newSystem = new systemClass(...args)
 			newSystem.components = components
+
+			// Add the system, return its ID
 			this.systems.push(newSystem)
 			return this.systems.length - 1
 		}
@@ -89,35 +93,29 @@ class World {
 	// Calls initialize() on all systems
 	initialize(...args) {
 		for (let system of this.systems) {
-			if (isFunction(system.initialize)) {
-				system.initialize.call(system, ...args)
-			}
+			invoke(system, 'initialize', ...args)
 		}
 	}
 
 	// Calls pre, every, and post on all systems
 	run(...args) {
 		for (let system of this.systems) {
-			if (isFunction(system.pre)) {
-				system.pre.call(system, ...args)
-			}
+			invoke(system, 'pre', ...args)
 
 			// Run the "every" method in the system
 			if (isFunction(system.every)) {
-				this.every(system.components, system.every, system, ...args)
+				this.every(system.components, system.every.bind(system), ...args)
 			}
 
-			if (isFunction(system.post)) {
-				system.post.call(system, ...args)
-			}
+			invoke(system, 'post', ...args)
 		}
 	}
 
 	// Iterate through entities with the specified components
 	// world.every(['comp'], comp => {comp.value = 0})
 	// Get an iterator for the entities
 	// let it = world.every(['comp'])
-	every(componentNames, callback, that, ...args) {
+	every(componentNames, callback, ...args) {
 		// Get indexed map of entities
 		let entities = this.index.query(componentNames)
 
@@ -131,22 +129,22 @@ class World {
 					// Get all components as an array
 					let comps = componentNames.map(name => ent.get(name))
 
-					// Add entity itself then any additional arguments after the components
-					comps.push(ent, ...args)
-
-					// Expand array as parameters to the method
-					if (that === undefined) {
-						callback(...comps)
-					} else {
-						callback.call(that, ...comps)
-					}
+					// Pass components, then the main entity, then any additional arguments
+					callback(...comps, ent, ...args)
 				}
 			}
 		}
 
 		return entities.values()
 	}
 
+	// Returns an array of entities with matching components
+	// Simplified version of every(), returns an actual array, and only takes component names as arguments
+	// world.get('player', 'sprite')
+	get(...componentNames) {
+		return [...this.every([...componentNames])]
+	}
+
 	// Registers entity prototype(s)
 	// Must be either a string or an object
 	// Top level must be prototype names

src/utilities.js

@@ -0,0 +1,7 @@
+function invoke(object, method, ...args) {
+	if (object && typeof object[method] === 'function') {
+		return object[method].call(object, ...args)
+	}
+}
+
+exports.invoke = invoke

test/tests.js

@@ -168,6 +168,19 @@ describe('World', function() {
 			})
 			assert(count === 0)
 		})
+		it('test entity creation with onCreate', function() {
+			let world = new World()
+			world.component('sprite', class {
+				onCreate(entity) {
+					this.entity = entity
+					this.x = 1
+				}
+			})
+
+			let ent = world.entity().set('sprite')
+			assert(ent.get('sprite').entity === ent)
+			assert(ent.get('sprite').x === 1)
+		})
 		it('test clearing with onRemove', function() {
 			let spriteCount = 0
 			let world = new World()
@@ -216,6 +229,8 @@ describe('World', function() {
 			assert(spriteCount === 2)
 			assert(Object.keys(world.entities).length === 1)
 			assert(getSize(world.every(['position'])) === 1)
+			assert(world.get('position').length === 1)
+			assert(world.get('position')[0].get('position').x === 2)
 			assert(ent.get('position').x === 1)
 
 			// Test attaching
@@ -224,6 +239,7 @@ describe('World', function() {
 			assert(spriteCount === 2)
 			assert(Object.keys(world.entities).length === 2)
 			assert(getSize(world.every(['position'])) === 2)
+			assert(world.get('position').length === 2)
 			assert(ent.get('position').x === 1)
 
 			// Test edge cases