Angular X中使用ngrx的方法详解（附源码）
时间：2020-12-14 14:50:57 | 栏目：AngularJS | 点击：次
前言
ngrx 是 Angular框架的状态容器，提供可预测化的状态管理。下面话不多说，来一起看看详细的介绍：
1.首先创建一个可路由访问的模块 这里命名为：DemopetModule。
包括文件：demopet.html、demopet.scss、demopet.component.ts、demopet.routes.ts、demopet.module.ts
代码如下：
demopet.html
<!--暂时放一个标签--> <h1>Demo</h1>
demopet.scss
h1{
color:#d70029;
}
demopet.component.ts
import { Component} from '@angular/core';
@Component({
selector: 'demo-pet',
styleUrls: ['./demopet.scss'],
templateUrl: './demopet.html'
})
export class DemoPetComponent {
//nothing now...
}
demopet.routes.ts
import { DemoPetComponent } from './demopet.component';
export const routes = [
{
path: '', pathMatch: 'full', children: [
{ path: '', component: DemoPetComponent }
]
}
];
demopet.module.ts
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { routes } from './demopet.routes';
@NgModule({
declarations: [
DemoPetComponent,
],
imports: [
CommonModule,
FormsModule,
RouterModule.forChild(routes)
],
providers: [
]
})
export class DemoPetModule {
}
整体代码结构如下：
运行效果如下：只是为了学习方便，能够有个运行的模块
2.安装ngrx
npm install @ngrx/core --save npm install @ngrx/store --save npm install @ngrx/effects --save
@ngrx/store是一个旨在提高写性能的控制状态的容器
3.使用ngrx
首先了解下单向数据流形式
代码如下：
pet-tag.actions.ts
import { Injectable } from '@angular/core';
import { Action } from '@ngrx/store';
@Injectable()
export class PettagActions{
static LOAD_DATA='Load Data';
loadData():Action{
return {
type:PettagActions.LOAD_DATA
};
}
static LOAD_DATA_SUCCESS='Load Data Success';
loadDtaSuccess(data):Action{
return {
type:PettagActions.LOAD_DATA_SUCCESS,
payload:data
};
}
static LOAD_INFO='Load Info';
loadInfo():Action{
return {
type:PettagActions.LOAD_INFO
};
}
static LOAD_INFO_SUCCESS='Load Info Success';
loadInfoSuccess(data):Action{
return {
type:PettagActions.LOAD_INFO_SUCCESS,
payload:data
};
}
}
pet-tag.reducer.ts
import { Action } from '@ngrx/store';
import { Observable } from 'rxjs/Observable';
import { PettagActions } from '../action/pet-tag.actions';
export function petTagReducer(state:any,action:Action){
switch(action.type){
case PettagActions.LOAD_DATA_SUCCESS:{
return action.payload;
}
// case PettagActions.LOAD_INFO_SUCCESS:{
// return action.payload;
// }
default:{
return state;
}
}
}
export function infoReducer(state:any,action:Action){
switch(action.type){
case PettagActions.LOAD_INFO_SUCCESS:{
return action.payload;
}
default:{
return state;
}
}
}
NOTE:Action中定义了我们期望状态如何发生改变 Reducer实现了状态具体如何改变
Action与Store之间添加ngrx/Effect 实现action异步请求与store处理结果间的解耦
pet-tag.effect.ts
import { Injectable } from '@angular/core';
import { Effect,Actions } from '@ngrx/effects';
import { PettagActions } from '../action/pet-tag.actions';
import { PettagService } from '../service/pet-tag.service';
@Injectable()
export class PettagEffect {
constructor(
private action$:Actions,
private pettagAction:PettagActions,
private service:PettagService
){}
@Effect() loadData=this.action$
.ofType(PettagActions.LOAD_DATA)
.switchMap(()=>this.service.getData())
.map(data=>this.pettagAction.loadDtaSuccess(data))
@Effect() loadInfo=this.action$
.ofType(PettagActions.LOAD_INFO)
.switchMap(()=>this.service.getInfo())
.map(data=>this.pettagAction.loadInfoSuccess(data));
}
4.修改demopet.module.ts 添加 ngrx支持
import { StoreModule } from '@ngrx/store';
import { EffectsModule } from '@ngrx/effects';
import { PettagActions } from './action/pet-tag.actions';
import { petTagReducer,infoReducer } from './reducer/pet-tag.reducer';
import { PettagEffect } from './effect/pet-tag.effect';
@NgModule({
declarations: [
DemoPetComponent,
],
imports: [
CommonModule,
FormsModule,
RouterModule.forChild(routes),
//here new added
StoreModule.provideStore({
pet:petTagReducer,
info:infoReducer
}),
EffectsModule.run(PettagEffect)
],
providers: [
PettagActions,
PettagService
]
})
export class DemoPetModule { }
5.调用ngrx实现数据列表获取与单个详细信息获取
demopet.component.ts
import { Component, OnInit, ViewChild, AfterViewInit } from '@angular/core';
import { Observable } from "rxjs";
import { Store } from '@ngrx/store';
import { Subscription } from 'rxjs/Subscription';
import { HttpService } from '../shared/services/http/http.service';
import { PetTag } from './model/pet-tag.model';
import { PettagActions } from './action/pet-tag.actions';
@Component({
selector: 'demo-pet',
styleUrls: ['./demopet.scss'],
templateUrl: './demopet.html'
})
export class DemoPetComponent {
private sub: Subscription;
public dataArr: any;
public dataItem: any;
public language: string = 'en';
public param = {value: 'world'};
constructor(
private store: Store<PetTag>,
private action: PettagActions
) {
this.dataArr = store.select('pet');
}
ngOnInit() {
this.store.dispatch(this.action.loadData());
}
ngOnDestroy() {
this.sub.unsubscribe();
}
info() {
console.log('info');
this.dataItem = this.store.select('info');
this.store.dispatch(this.action.loadInfo());
}
}
demopet.html
<h1>Demo</h1>
<pre>
<ul>
<li *ngFor="let d of dataArr | async">
DEMO : {{ d.msg }}
<button (click)="info()">info</button>
</li>
</ul>
{{ dataItem | async | json }}
<h1 *ngFor="let d of dataItem | async"> {{ d.msg }} </h1>
</pre>
6.运行效果
初始化时候获取数据列表
点击info按钮 获取详细详细
7.以上代码是从项目中取出的部分代码，其中涉及到HttpService需要自己封装，data.json demo.json两个测试用的json文件，名字随便取的当时。
http.service.ts
import { Inject, Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions, URLSearchParams } from '@angular/http';
import { Observable } from "rxjs";
import 'rxjs/add/operator/map';
import 'rxjs/operator/delay';
import 'rxjs/operator/mergeMap';
import 'rxjs/operator/switchMap';
import 'rxjs/add/operator/catch';
import 'rxjs/add/observable/throw';
import { handleError } from './handleError';
import { rootPath } from './http.config';
@Injectable()
export class HttpService {
private _root: string="";
constructor(private http: Http) {
this._root=rootPath;
}
public get(url: string, data: Map<string, any>, root: string = this._root): Observable<any> {
if (root == null) root = this._root;
let params = new URLSearchParams();
if (!!data) {
data.forEach(function (v, k) {
params.set(k, v);
});
}
return this.http.get(root + url, { search: params })
.map((resp: Response) => resp.json())
.catch(handleError);
}
}
8.模块源代码
总结