How to do correct Repository factory? - angularjs

Question

i have some free days between projects so i decided to learn typescript.
Therefore i want to do a repository factory. The idea is simple, there is some API where i can access models crud actions. It is nice solution to have one generic repository for buisnes models. But still get the model class from CRUD methods.
What is the correct way to do it ? Can someone help me solve this? How to do it right ?
What i want to achive is:
var factory = new RepositoryFactory($resource, 'http://api.com');
var repo = factory.getRepository(User);
var user = repo.getAll();
I starded to do somethink like this:
IEntity:
'use strict';
export interface IEntity {
id: number;
}
IRepository:
'use strict';
import {IEntity} from "./IEntity";
export interface IRepository<T extends IEntity> {
getAll(params:Object): T[];
getById(id:number): T;
create(data:Object): T;
update(id:number, data:{id:number}): T;
remove(id:number): boolean;
}
RepositoryFactory
'use strict';
import {IEntity} from "./IEntity";
import {Repository} from "./Repository";
export default class RepositoryFactory {
protected $resource:any;
protected url:string;
constructor($resource:any, url:string) {
this.$resource = $resource;
this.url = url;
}
public getRepository<T extends IEntity>(model:T):Repository {
return new Repository(this.$resource, this.url, model)
}
}
`Repository`:
'use strict';
import {IRepository} from "./IRepository";
import {IEntity} from "./IEntity";
export default class Repository<T extends IEntity> implements IRepository<T> {
protected $resource:any;
protected resource:any;
protected url:string;
protected model:T;
constructor($resource:any, url:string, model:T) {
this.$resource = $resource;
this.url = url;
this.model = model;
this.resource = this.getResource(model.path);
}
getAll(params:Object):T[] {
let results = this.resource.query((typeof params === 'undefined' ? {} : params), this.onSuccess);
return this.returnPromise(results);
}
getById(id:number):T {
let model = this.resource.get({id: id}, this.onSuccess);
return this.returnPromise(model);
}
create(data:Object):T {
let model = new this.resource(data);
return model.$save().then(this.onSuccess);
}
update(id:number, data:Object):T {
data.id = id;
var model = new this.resource(data);
return model.$update().then(this.onSuccess);
}
remove(id:number):boolean {
var data = {id: id};
var model = new this.resource(data);
return model.$delete().then(this.onSuccess);
}
protected getResource(path:string) {
return this.$resource(this.url + path, {id: '#id'}, {
'update': {
method: 'PUT'
},
'get': {
method: 'GET'
},
'save': {
method: 'POST'
},
'query': {
method: 'GET'
},
'remove': {
method: 'DELETE'
},
'delete': {
method: 'DELETE'
}
});
}
protected onSuccess(response:any) {
if (this.checkPropertyExistence(response, 'data')) {
if (response.data instanceof Array) {
let results = response.data;
for (var key in results) {
if (results.hasOwnProperty(key)) {
results[key] = new this.model(results[key]);
}
}
return results;
} else {
return new this.model(response.data);
}
}
return response;
}
protected transformRequest(obj:Object) {
var str = [];
for (var p in obj) {
if (obj.hasOwnProperty(p)) {
str.push(encodeURIComponent(p) + "=" + encodeURIComponent(obj[p]));
}
}
return str.join("&");
}
protected returnPromise(object:Object) {
return object.$promise.then(function (result) {
return result;
});
}
protected checkPropertyExistence(obj:Object, paths:string|string[]) {
for (var i = 0; i < paths.length; i++) {
if (!obj || !obj.hasOwnProperty(paths[i])) {
return false;
}
obj = obj[paths[i]];
}
return true;
}
}
User:
'use strict';
import {IEntity} from "./IEntity";
export default class User implements IEntity {
id:number;
name:string;
static _path:string = '/users';
constructor(id:number, name:string) {
this.id = id;
this.name = name;
}
static get path():string {
return this._path;
}
}

Answer 1

Hey guys i have menage to created working example for you.
The example shows how to create repository factory with typescript.
I have prepared this DEMO FIDDLE where you can press RUN on the right side, and the page with single button will appear. After clicking the button console.log will display getAll method results.
In example i have mocked data, simply to show that factory works. If anyone wants to improves it, feel free and welcome to do it!
How it works?
//create factory, you can do it in an abstract controller class
//and later extends controller by it so you can easy get access to repository
var factory = new RepositoryFactory();
//inject path for $resource (unused in example)
//and your model.entity namespace
var repo = factory.getRepository('/users', 'User');
//call repo method
var users = repo.getAll({});
When using angular create RepositoryFactory as a service. Thats all. You may also want to inject $resource to get the right data from API.
And here is a full example code:
interface IEntity {
id: number;
}
class Entity implements IEntity {
private _id:number;
private _name:string;
private _birth:Date;
constructor(parameters: {id:number, name:string, birth:Date}) {
this._id = parameters.id;
this._name = parameters.name;
this._birth = parameters.birth;
}
get id():number {
return this._id;
}
set id(value:number) {
this._id = value;
}
get name():string {
return this._name;
}
set name(value:string) {
this._name = value;
}
get birth():Date {
return this._birth;
}
set birth(value:Date) {
this._birth = value;
}
}
class RepositoryFactory {
public getRepository<T extends IEntity>(path:string, model:string):IRepository<T> {
return new Repository<T>(path, model)
}
}
interface IRepository<T extends IEntity> {
getAll(params:Object): T[];
getById(id:number): T;
create(data:Object): T;
update(id:number, data:{id:number}): T;
remove(id:number): boolean;
}
class Repository<T extends IEntity> implements IRepository<T> {
protected path:string;
protected model:string;
constructor(path:string, model:string) {
this.path = path;
this.model = model;
}
getAll(params:Object):T[] {
let results = [
{id:1, name: 'rafal', birth:new Date()},
{id:2, name: 'szymon', birth:new Date()},
{id:3, name: 'mateusz', birth:new Date()},
];
let entities= [];
for (var key in results) {
if (results.hasOwnProperty(key)) {
let entity = Object.create(window[this.model].prototype);
entity.constructor.apply(entity, new Array(results[key]));
entities.push(entity);
}
}
return entities;
}
getById(id:number):T {
let object = {id:id, name: 'test', birth:new Date()};
var entity = Object.create(window[this.model].prototype);
entity.constructor.apply(entity, new Array(object));
return entity;
}
create(data:Object):T {
var entity = Object.create(window[this.model].prototype);
entity.constructor.apply(entity, new Array(data));
return entity;
}
update(id:number, data:Object):T {
var entity = Object.create(window[this.model].prototype);
entity.constructor.apply(entity, new Array(data));
return entity;
}
remove(id:number):boolean {
return true;
}
}
var factory = new RepositoryFactory();
var repo = factory.getRepository('/users', 'Entity');
var users = repo.getAll({});