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angular技巧

作者:互联网

目录

声明

declarations: [AppComponent]

组件、管道、指令


引入模块

imports: [BrowserModule, AppRoutingModule]

其他模块


服务

providers: [UserService]

此模块将生成的根组件

例子:

bootstrap: [AppComponent]

此模块将生成的主要组件(组件树的顶部父节点)


动态生成的组件

例子:

entryComponents: [PopupComponent]

动态生成的组件(例如使用 ViewContainerRef.createComponent())


出口

例子:

export: [TextDirective, PopupComponent, BrowserModule]

我们希望在另一个模块中访问它们的组件、指令、模块或管道(在导入此模块后)

去掉测试文件

"schematics": {
        "@schematics/angular:component": {
          "style": "scss",
          "skipTests": true
        },
        "@schematics/angular:application": {
          "strict": true
        },
        "@schematics/angular:directive": {
          "skipTests": true
        },
        "@schematics/angular:modules": {
          "skipTests": true
        },
        "@schematics/angular:pipe": {
          "skipTests": true
        },
        "@schematics/angular:service": {
          "skipTests": true
        },
        "@schematics/angular:class": {
          "skipTests": true
        }
      },

模块的使用

textOne.ts

export const a = 1;
export const b = 2;

使用
import * as textOne from './textOne'

console.log(textOne.a);

combineLatest

多个请求合并成一个

  combineLatest(  
      this.http.getAllReceivers(),
      this.http.getAllReceiverGroups(),
      this.http.getAllShiftPlans(),
      (recipient, recipientGroup, schedulePlan) => ({
        recipient,
        recipientGroup,
        schedulePlan,
      })
    ).subscribe(({recipient, recipientGroup, schedulePlan}) => {
       
    });

ts技巧

const closureLibraryLocales = [
  'af', 'am', 'ar', 'ar-DZ', 'az', 'be', 'bg', 'bn', 'br', 'bs',
  'ca', 'chr', 'cs', 'cy', 'da', 'de', 'de-AT', 'de-CH', 'el', 'en-AU',
] as const;
type ClosureLibraryLocaleName = typeof closureLibraryLocales[number];
    // "af" | "am" | "ar" | "ar-DZ" | "az" | "be" ...
const a: ClosureLibraryLocaleName='af'
const closureLibraryAliases: {[l in ClosureLibraryLocaleName]?: string[]} = {
  'id': ['in'],
  'he': ['iw']
}

angular 各版本的兼容

https://gist.github.com/LayZeeDK/c822cc812f75bb07b7c55d07ba2719b3#file-angular-cli-node-js-typescript-rxjs-compatiblity-matrix-csv

FormArray 倒序删除

其实就是清空, 或者用while删除一直删除第一项

if (this.getKvArr.length) {
      for (let i = this.getKvArr.controls.length; i-- > 0;) {
        const valItem = this.getKvArr.at(i);
        if (!this.keys.some(key => key.tag === valItem.get('key').value)) {
          this.getKvArr.removeAt(this.getKvArr.length - i);
        }
      }
    }

为啥不用clear() 去清空, 因为需要上,我至少要保留一项, 而不是全部清空

一种有效取消订阅的方式

可以把订阅放到服务里面

@Injectable()
export class Destroy extends Observable<void> implements OnDestroy {
  private readonly destroySubject$ = new Subject();

  constructor() {
  }

  ngOnDestroy(): void {
    this.destroySubject$.next();
    this.destroySubject$.complete();
  }
}
引入
 constructor(
    private readonly destroy$: Destroy
  ) {}

 .pipe(takeUntil(this.destroy$))

服务的使用

  providers: [
    {
      provide: 'demo1',
      useFactory: (demoService: DemoService): Array<number> => {
        console.log(demoService.loadRoute);
        if (demoService.loadRoute) {
          return [1,2,3]
        } else {
          return [4,5,6]
        }
      },
      deps: [DemoService],
      multi: true,
    }
  ]

@Injectable({
  providedIn: 'root'
})
export class DemoService {
  loadRoute = Math.random() * 10 > 5;

  constructor() {
  }
}

可以做一些延迟加载的配置

组件传入的参数

<app-report2 [size]="1" data-size="10"></app-report2>

组件
  @Input()
  @HostBinding('attr.data-size')
  size = 100;

如果值size=1 , 那么属性的值data-sizesize都为 1

如果size不输入 ,那么默认data-sizesize 都为100

var

两个参数

:host {
  --sex: red;
}

.aaa {
  background-color: var(--sex, blue); /* red */
  background-color: var(--sex, blue); /* blue */ 
}

DomSanitizer 防止XSS攻击

export class Report2Component implements OnInit, AfterViewInit {
      color1 = '#f4f4f4';
      html1 = `<h1>我是一个h1标签</h1>`;
      getHtml(): SafeHtml {
        return this.sanitizer.bypassSecurityTrustHtml(this.html1);
      }

      getColor(): SafeStyle {
        return this.sanitizer.bypassSecurityTrustStyle(this.color1);
      }
}
<p [style.background]="getColor()">kkkkkkkkkk</p>
<div [innerHTML]="getHtml()"></div>

HostBinding

export type TuiSizeXL = 'm' | 'l' | 'xl';
const WIDTH: Record<TuiSizeXL, number> = {
    m: 0.25,
    l: 0.375,
    xl: 0.5625,
};
  @HostBinding('style.fontSize')
    get strokeWidth(): number {
        return WIDTH[this.size];
    }

如果size 值发现变化, 对应的值也会跟着变化

可以替代Input() set 父传子修改的对应修改

标签:const,技巧,模块,组件,schematics,angular,size
来源: https://www.cnblogs.com/fangdongdemao/p/15906998.html