나는 TDD 자바 스크립트에 ebook on GitHub에서 일하고 있는데, 나는 대중적인 상속 패턴을 놓치고 있는지 궁금해. 추가 패턴을 알고 있다면 그 패턴을보고 싶습니다. 그들은 다음이 있어야합니다인기있는 자바 스크립트 상속 패턴
- 시간 테스트 -
- 소스 코드를 제공해야 실제 응용 프로그램에 사용됩니다. 가능한 한 솔직하고 똑똑해야합니다.
- 물론 정확하고 올바르게 작동해야합니다.
내가 이것을하고있는 이유는 자바 스크립트에서 객체 상속이 매우 어려웠던 것으로 보인다는 점입니다. 내 JavaScript 상속 장은 기본적으로 Crockford의 Good Parts 및 Zakas의 웹 개발자 용 JavaScript 전문 학습 도구입니다.
:// Pseudoclassical Inheritance
function Animal(name) {
this.name = name;
this.arr = [1,2,3];
};
Animal.prototype = {
constructor: Animal,
whoAmI: function() { return "I am " + this.name + "!\n"; }
};
function Dog(name, breed) {
this.name = name;
this.breed = breed;
};
Dog.prototype = new Animal();
Dog.prototype.getBreed = function() {
return this.breed;
};
Dog.prototype.bark = function() {
return 'ruff ruff';
};
// Combination Inheritance
function Parent(name) {
this.name = name;
this.arr = [1,2,3];
};
Parent.prototype = {
constructor: Parent,
toString: function() { return "My name is " + this.name; }
};
function Child(name, age) {
Parent.call(this, name);
this.age = age;
};
Child.prototype = new Parent();
Child.prototype.getAge = function() {
return this.age;
};
// Prototypal Inheritance
var helper = { // Thanks to Bob Vince for reminding me NOT to clobber Object!
inherit: function(p) {
NewObj = function(){};
NewObj.prototype = p;
return new NewObj();
},
inheritPrototype: function(subType, superType) {
var prototype = helper.inherit(superType.prototype);
prototype.constructor = subType;
subType.prototype = prototype;
}
};
function SubType(name, age) {
Parent.call(this, name);
this.age = age;
};
//Child.prototype = new Parent(); // Gets replaced by:
helper.inheritPrototype(SubType, Parent);
SubType.prototype.getAge = function() {
return this.age;
};
// Functional - Durable Pattern
function super_func(blueprint) {
var obj = {};
obj.getName = function() { return blueprint.name; };
obj.getAge = function() { return blueprint.age; };
obj.getFoo = function() { return blueprint.foo; };
obj.getBar = function() { return blueprint.bar; };
return obj;
};
function sub_func(blueprint) {
blueprint.name = blueprint.name || "Crockford's Place";
supr = super_func(blueprint);
supr.coolAugment = function() { return "I give a fresh new perspective on things!" };
return supr;
};
그리고 그 관심에 대한
, 여기에 jspec 테스트 (죄송하지만 마크 다운 또는 무엇이든 그들이 사용하고있는 미치게 형식 조금)입니다 : 여기 내가 지금까지 가지고있는 패턴이다describe 'JavaScript Inheritance Tests'
before_each
animal = new Animal("Onyx")
dog = new Dog("Sebastian", "Lab")
person = { password : 'secret', toString : function(){ return '<Person>' } }
stub(person, 'toString').and_return('Original toString method!')
end
describe 'Pseudoclassical Inheritance Creation'
it 'should create parent and child object using pseudoclassical inheritance'
animal.constructor.should.eql Animal
// dog.constructor.should.eql Dog // Nope: expected Animal to eql Dog
dog.constructor.should.eql Animal
animal.should.be_a Animal
dog.should.be_a Animal
// dog.should.be_a Dog // Nope! We severed the original prototype pointer and now point to Animal!
dog.should.be_an_instance_of Animal
dog.should.be_an_instance_of Dog
(animal instanceof Dog).should.be_false
end
it 'should behave such that child inherits methods and instance variables defined in parent'
animal.whoAmI().should.match /I am Onyx.*/
dog.whoAmI().should.match /Sebastian.*/
animal.should.respond_to 'whoAmI'
dog.should.respond_to 'whoAmI'
dog.should.have_prop 'name'
end
it 'should behave such that methods and instance variables added to child are NOT available to parent'
dog.bark().should.match /Ruff Ruff/i
dog.should.have_property 'breed'
dog.should.respond_to 'bark'
// animal.should.have_prop 'breed' // Of course not!
// animal.should.respond_to 'bark' // Of course not!
end
it 'should behave such that reference variables on the parent are "staticy" to all child instances'
dog.arr.should.eql([1,2,3])
dog.arr.push(4)
dog.arr.should.eql([1,2,3,4])
spike = new Dog("Spike", "Pitbull")
spike.arr.should.eql([1,2,3,4])
spike.arr.push(5)
rover = new Dog("Rover", "German Sheppard")
spike.arr.should.eql([1,2,3,4,5])
rover.arr.should.eql([1,2,3,4,5])
dog.arr.should.eql([1,2,3,4,5])
end
end
describe 'Combination Inheritance Solves Static Prototype Properties Issue'
it 'should maintain separate state for each child object'
child_1 = new Child("David", 21)
child_2 = new Child("Peter", 32)
child_1.arr.push(999)
child_2.arr.push(333)
child_1.arr.should.eql([1,2,3,999])
child_2.arr.should.eql([1,2,3,333])
child_1.getAge().should.eql 21
child_1.should.be_a Parent
end
end
describe 'Prototypal Inheritance'
it 'should inherit properties from parent'
person.toString().should.match /Original toString.*/i
person.password.should.eql 'secret'
joe = helper.inherit(person)
joe.password.should.eql 'secret'
joe.password = 'letmein'
joe.password.should.eql 'letmein'
person.password.should.eql 'secret'
end
end
describe 'Parisitic Combination Inheritance'
it 'should use inheritPrototype (to call parent constructor once) and still work as expected'
sub = new SubType("Nicholas Zakas", 29)
sub.toString().should.match /.*Nicholas Zakas/
sub.getAge().should.eql 29
charlie = new SubType("Charlie Brown", 69)
charlie.arr.should.eql([1,2,3])
charlie.arr.push(999)
charlie.arr.should.eql([1,2,3,999])
sub.arr.should.eql([1,2,3])
sub.should.be_an_instance_of SubType
charlie.should.be_an_instance_of SubType
(sub instanceof SubType).should.eql true
(sub instanceof Parent).should.eql true
end
end
describe 'Functional Durable Inheritance'
it 'should hide private variables'
sup = new super_func({name: "Superfly Douglas", age: 39, foo: "foo", bar: "bar"})
sup.getName().should.eql 'Superfly Douglas'
sup.name.should.be_undefined
sup.getAge().should.eql 39
sup.age.should.be_undefined
sup.getFoo().should.eql 'foo'
sup.foo.should.be_undefined
end
it 'should create a descendent object that inherits properties while maintaining privacy'
sub = new sub_func({name: "Submarine", age: 1, foo: "food", bar: "barfly"})
sub.getName().should.eql 'Submarine'
sub.name.should.be_undefined
sub.getAge().should.eql 1
sub.age.should.be_undefined
sub.getFoo().should.eql 'food'
sub.foo.should.be_undefined
sub.getBar().should.eql 'barfly'
sub.bar.should.be_undefined
sub.coolAugment().should.match /.*fresh new perspective.*/
//sub.should.be_an_instance_of super_func NOPE!
//sub.should.be_an_instance_of sub_func NOPE!
sub.should.be_an_instance_of Object
end
end
end
감사합니다. 당신이 나의 에세이/책을 체크 아웃 할 경우 아, 그리고 피드백을 얻을 싶어요 : TDD JavaScript at GitHub repo
많은 프로젝트에서 많은 기술을 시도했습니다. 필자가 가장 좋아하는 것은 Object.create()를 사용하여 기본 프로토 타입을 인스턴스화하는 것입니다. 내 블로그를 확인하십시오 : http://ncombo.wordpress.com/2013/07/11/javascript-inheritance-done-right/ – Jon