Angular2 本地存储LocalStorage的使用

我的其它博客将同步更新：CSDN、简书、github

在网站开发过程中，总有一些类似记录用户喜好的数据需要保存在客户端，比如记住用户名密码等。常规第一反应是使用cookie，但是cookie的使用有诸多的限制。于是HTML5规范中出来了LocalStorage，大小为5M。
Angular2 关于LocalStorage的使用在github上有些例子，但大多都是基于2.0.* 或是beta版本的。我用的是最新版本Angular 2.1用不了，于是手动改了下。

一、参考github项目：

https://github.com/NilsHolger/angular2todoes

https://github.com/rrgarciach/angular2-local-storage

二、环境：

Angular 2.1

三、实现：

添加文件app/core/common/local.storage.ts（文件位置根据自己喜好）

 import {Provider} from '@angular/core'; 
export class LocalStorage {

public localStorage:any;

    constructor() {
if (!localStorage) {
throw new Error('Current browser does not support Local Storage');
        }
this.localStorage = localStorage;
    }

public set(key:string, value:string):void {
this.localStorage[key] = value;
    }

public get(key:string):string {
return this.localStorage[key] || false;
    }

public setObject(key:string, value:any):void {
this.localStorage[key] = JSON.stringify(value);
    }

public getObject(key:string):any {
return JSON.parse(this.localStorage[key] || '{}');
    }

public remove(key:string):any {
this.localStorage.removeItem(key);
    }
}
// export const LOCAL_STORAGE_PROVIDERS:any[] = [
// Provider(LocalStorage, {useClass: LocalStorage})
// ];

四、使用：

1、在文件app.module.ts 中引用


import { LocalStorage } from './core/common/local.storage';
...
@NgModule({
...
   providers: [LocalStorage,...],
...
})

2、在你的Component 中使用

 ...
// 引用
import { LocalStorage } from '../core/common/local.storage'
     // 注入
     constructor(
        private ls: LocalStorage,
...   
     ) 

    get(): void {
        // 读取LocalStorage
        this.cache = this.ls.getObject("logincache") ; 
    }
    set(): void { 
        // 写入LocalStorage
        this.ls.setObject("logincache",this.cache) ;
    }

五、总结：

  才接触不太久，又没有Angular1的基础，使用Angular2比较吃力。网上资源太少，走的很艰难，只有多次修改、报错、再修改。
  以下是相关文件的全部代码，由于不是单独例子，多余其它功能代码请忽略，如你有更好的方法，欢迎指正！

1、文件app/core/common/local.storage.ts

import {Provider} from '@angular/core'; 
export class LocalStorage {

public localStorage:any;

    constructor() {
if (!localStorage) {
throw new Error('Current browser does not support Local Storage');
        }
this.localStorage = localStorage;
    }

public set(key:string, value:string):void {
this.localStorage[key] = value;
    }

public get(key:string):string {
return this.localStorage[key] || false;
    }

public setObject(key:string, value:any):void {
this.localStorage[key] = JSON.stringify(value);
    }

public getObject(key:string):any {
return JSON.parse(this.localStorage[key] || '{}');
    }

public remove(key:string):any {
this.localStorage.removeItem(key);
    }
}
// export const LOCAL_STORAGE_PROVIDERS:any[] = [
// Provider(LocalStorage, {useClass: LocalStorage})
// ];

2、文件app.module.ts


import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import {NgbModule} from '@ng-bootstrap/ng-bootstrap';

import './rxjs-extensions';

import { LocalStorage } from './core/common/local.storage';

import { AppComponent } from './app.component';
import { IndexComponent } from './index/index.component';
import { MainComponent } from './main/main.component';
import { HelpComponent } from './help/help.component';

import { Session } from './core/auth/session';

import { AuthService } from './core/auth/auth.service';
import { UserService } from './core/user/user.service';

import { AppRoutingModule }     from './app-routing.module';

@NgModule({
imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    AppRoutingModule, 
  ],
declarations: [
    AppComponent,IndexComponent,MainComponent,HelpComponent
  ],
providers: [LocalStorage,AuthService,UserService],
bootstrap: [AppComponent]
})
export class AppModule { }

3、文件app/index/index.component.ts


import { Component,OnInit,Input   } from '@angular/core';
import { ActivatedRoute, Params } from '@angular/router';
import { Location }               from '@angular/common';

import { LocalStorage } from '../core/common/local.storage';

import { AuthService } from '../core/auth/auth.service';
import { Session }     from '../core/auth/session'; 
import { User }        from '../core/user/user'; 


import { LoginCache }        from './logincache'; 

@Component({
// moduleId:module.id,
  selector: 'app-index',
  templateUrl: './index.component.html',
  styleUrls: ['./index.component.css']
})
export class IndexComponent implements OnInit {
    @Input()
    cache:LoginCache;
    user:User;

    constructor(
private ls: LocalStorage,
private authService: AuthService, 
private route: ActivatedRoute,
private location: Location
    ) {}

    ngOnInit(): void {
this.cache = this.ls.getObject("logincache") ; 
    }
    tologin(): void { 
this.ls.setObject("logincache",this.cache) ;
this.authService.login(this.cache.account,this.cache.password)
                        .then(user => this.user);
    }

 }

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