inheritance, mixins and other stuff, mainly to encapsulate objects
Tính đến
Script này sẽ không được không được cài đặt trực tiếp. Nó là một thư viện cho các script khác để bao gồm các chỉ thị meta
// @require https://update.greasyfork.org/scripts/22752/145191/object-utils.js
// ==UserScript==
// @name object-utils
// @name:de object-utils
// @namespace dannysaurus.camamba
// @version 0.1
// @license MIT License
// @description inheritance, mixins and other stuff, mainly to encapsulate objects
// @description:de inheritance, mixins and other stuff, mainly to encapsulate objects
// ==/UserScript==
var LIB = LIB || {};
/**
*
* @type {{extend, TruthyFalsy, Truthy, Falsy, emptyFunction}}
*/
LIB.objectUtils = (function() {
'use strict';
/**
* Extends an object from another object through the prototype chain
* @param {Object} superObj - The object to be extended
* @param {Object} obj - The object extending the superObj
* @return {boolean} true, if executed successfully
*/
function _extend(superObj, obj){
if (typeof superObj === 'undefined') return false;
if (typeof obj === 'undefined') return false;
// save properties of prototype of the obj
var descriptors = {};
Object.getOwnPropertyNames(obj.prototype).forEach(function(propName) {
descriptors[propName] = Object.getOwnPropertyDescriptor(obj.prototype, propName);
});
// create a new extended prototype
obj.prototype = Object.create(superObj.prototype, descriptors);
obj.prototype.constructor = obj;
return true;
}
/**
* Clones properties from one object to another.
* A property only gets cloned if it does not yet exist in the target object.
* @param {Object} receiver - the target object receiver the properties
* @param {Object} supplier - the source object supplying the properties
* @param {Array} [props] - names of the relevant properties
* @return {boolean} true, if executed successfully
*/
function _mixin(receiver, supplier, props) {
if (typeof supplier === 'object') return false;
if (typeof receiver === 'object') return false;
var propNames = Array.isArray(props) ? props : Object.getOwnPropertyNames(supplier);
propNames.forEach(function(propName){
if (!Object.prototype.hasOwnProperty.call(receiver, propName)) {
var desc = Object.getOwnPropertyDescriptor(supplier, propName);
if (typeof desc !== 'undefined') {
Object.defineProperty(receiver, propName, desc);
}
}
});
return true;
}
/**
* Has an object extending a super object by their prototype objects.
* @param {Object} obj - The extending object
* @return {{from: extendFrom, mixWith: mixWith}}
*/
var extend = function(obj) {
/**
* Clones the prototype properties of the super object in the target object if the property does not yet exist there.
* @param {Object} superObj - the source object supplying the properties
* @param {Array} [props] - names of the relevant properties
* @return {{thenWith: mixWith}}
*/
var mixWith = function(superObj, props) {
if (_mixin(obj.prototype, superObj.prototype, props)){
return {
thenWith : mixWith
};
}
};
/**
* Extends the super object from the prototype chain
* @param superObj The super object to be extended
* @return {{mixWith: mixWith}}
*/
var extendFrom = function (superObj) {
if (_extend(superObj, obj)) {
return {
mixWith : mixWith
};
}
};
return {
from : extendFrom,
mixWith : mixWith
};
};
/**
* Defines an object that holds a value and specific values.
* In case the value is a Truthy, Falsy or undefined it is overwritten with specific values.
* @param value The common value.
* @param [ifTruthy] if not undefined it overwrites value when it is a Truthy
* @param [ifFalsy] if not undefined it overwrites value when it is a Falsy
* @param [ifUndefined] if not undefined it overwrites value when it is undefined
* @returns {TruthyFalsy}
* @constructor
*/
function TruthyFalsy(value, ifTruthy, ifFalsy, ifUndefined) {
if (!this instanceof TruthyFalsy) {
return new TruthyFalsy(value, ifTruthy, ifFalsy, ifUndefined);
}
this.value = value;
if (ifTruthy !== 'undefined') { this.ifTruthy = ifTruthy; }
if (ifFalsy !== 'undefined') { this.ifFalsy = ifFalsy; }
if (ifUndefined !== 'undefined') { this.ifUndefined = ifUndefined; }
}
TruthyFalsy.prototype = {
constructor : TruthyFalsy,
valueOf: function() {
var result = this.value;
if (typeof this.ifUndefined !== "undefined" && typeof result === "undefined") {
result = this.ifUndefined;
} else if (typeof this.ifTruthy !== "undefined" && result) {
result = this.ifTruthy;
} else if (typeof this.ifFalsy !== "undefined" && result) {
result = this.ifFalsy;
}
return result;
},
toString: function() {
return String(TruthyFalsy.prototype.valueOf.call(this));
}
};
function Falsy(value, ifFalsy, ifUndefined) {
if (!(this instanceof Falsy)) {
return new Falsy(value, ifFalsy, ifUndefined);
}
TruthyFalsy.call(this, value, undefined, ifFalsy, ifUndefined);
}
extend(Falsy).from(TruthyFalsy);
function Truthy(value, ifTruthy, ifUndefined) {
if (!(this instanceof Truthy)) {
return new Truthy(value, ifTruthy, ifUndefined);
}
TruthyFalsy.call(this, value, ifTruthy, undefined, ifUndefined);
}
extend(Truthy).from(TruthyFalsy);
/** placeholder for empty callbacks */
function emptyFunction() {}
/**
* Keeps elements assigned by an index
* @param {number} [initialCapacity] - initial size of the array used to store the elements
* @constructor
*/
function Keeper(initialCapacity) {
if (!(this instanceof Keeper)) {
return new Keeper(initialCapacity);
}
var _store = new Array(initialCapacity || 16);
var _pointer = 0;
Object.defineProperties(this, {
store: {
get: function() { return _store },
configurable: false, enumerable: false
},
pointer: {
get: function() { return _pointer },
configurable: false, enumerable: false
}
})
}
Keeper.prototype = {
constructor: Keeper,
/**
* Adds a new element
* @param {*|Object} item - The element to keep. Must not be type of <code>undefined</code>.
* @return {number} The index (key) of the added element.<br>
* <code>-1</code> if the element could not be added.
*/
push: function(item) {
if (typeof item !== 'undefined') {
var index = this.pointer;
this.store[index] = item;
for (this.pointer = index + 1; this.pointer <= this.store.length; this.pointer++) {
if (typeof this.store[pointer] === 'undefined') { break; }
}
if (this.pointer === this.store.length) {
this.store.length *= 2;
}
return index;
}
return -1;
},
/**
* Removes an element.
* @param index The index (key) of the element to be removed.
* @return {boolean} <code>true</code> if the element could be removed successfully
*/
remove: function(index) {
if (index + 1 >= this.store.length) {
this.store[index] = undefined;
this.pointer = index;
return true;
}
return false;
},
/**
* Gets the element with the specified index
* @param {number} index - Index (key) of the element
* @return {*|Object} the element with the specified index or <code>undefined</code>
*/
get: function (index) {
if (index + 1 <= this.store.length) {
return this.store[index];
}
return undefined;
}
};
return {
mixin: _mixin,
extend: extend,
TruthyFalsy: TruthyFalsy,
Truthy: Truthy,
Falsy: Falsy,
Keeper: Keeper,
get emptyFunction() { return emptyFunction }
};
})();