Angular 5/6:组件接口 - 可能吗？

Question

这就是我要完成的任务:创建一个包含MatStepper的组件,它将接受2..n步骤,每个步骤都有自己的组件.

话虽如此,我知道如何在其他语言中执行此操作的方式是创建具有公共行为的接口,并在不同的组件中实现它,但在包装器组件中使用接口.

向导step.component.ts

export interface WizardStep {
  isValid: boolean;

  nextClicked(e);
  previousClicked(e);
}

wizard.component.ts

import { Component, Input, OnInit, ViewChild } from '@angular/core';
import { ProgressBarType } from '../progress-bar/ProgressBarType';
import { MatStepper } from '@angular/material';
import { WizardStep } from './wizard-step.component';

@Component({
  selector: 'app-wizard',
  templateUrl: './wizard.component.html',
  styleUrls: [ './wizard.component.css' ]
})
export class WizardComponent implements OnInit {

  progress: number;
  progressBarType = ProgressBarType.Progress;

  @Input() steps: WizardStep[] = [];

  /**
   * The material stepper instance.
   */
  @ViewChild('stepper') private stepper: MatStepper;

  constructor() {
  }


  ngOnInit() {
    this.calculateProgress(0);
  }

  public calculateProgress(index: number): void {
    this.progress = ((index + 1) / this.steps.length) * 100;
  }

  public next(e): void {
    this.steps[e.selectedIndex].nextClicked(e);
  }

  public previous(e): void {
    this.steps[e.selectedIndex].previousClicked(e);
  }

  public selectionChange(e):void {
    this.calculateProgress(e.selectedIndex);
  }
}

wizard.component.html

<panel>
  <progress-bar class="progress-margins" [progress]="progress" [type]="progressBarType"></progress-bar>
  <mat-horizontal-stepper class="hide-header" #stepper (selectionChange)="selectionChange($event)">
    <mat-step *ngFor="let step of steps">
      <ng-container *ngComponentOutlet="step"></ng-container>
    </mat-step>
  </mat-horizontal-stepper>

  <form-buttons
    primaryLabel="Next"
    (primaryButtonClicked)="stepper.next(); next($event)"
    secondaryLabel="Previous"
    (secondaryButtonClicked)="stepper.previous(); previous($event)">
  </form-buttons>
</panel>

然后,我通过为每个向导步骤创建一个带有组件的验证组件来尝试使用此组件:

向导validation.component.ts

import { Component, OnInit } from '@angular/core';
import { WizardStep } from 'framework';
import { WizardValidationStep1Component } from '../wizard-validation-step1/wizard-validation-step1.component';
import { WizardValidationStep2Component } from '../wizard-validation-step2/wizard-validation-step2.component';
import { WizardValidationStep3Component } from '../wizard-validation-step3/wizard-validation-step3.component';

@Component({
  selector: 'app-wizard-validation',
  templateUrl: './wizard-validation.component.html',
  styleUrls: []
})
export class WizardValidationComponent implements OnInit {

  steps: WizardStep[] = [];

  constructor() {
  }

  ngOnInit() {
    this.steps.push(WizardValidationStep1Component);
    this.steps.push(WizardValidationStep2Component);
    this.steps.push(WizardValidationStep3Component);
  }

}

向导validation.component.html

<wizard [steps]="steps">
</wizard>

最后,WizardValidationStep1Component,WizardValidationStep2Component和WizardValidationStep3Component在这一点上完全相同:

import { Component } from '@angular/core';

import { WizardStep } from 'framework';

@Component({
  selector: 'app-wizard-validation-step1',
  templateUrl: './wizard-validation-step1.component.html',
  styleUrls: []
})
export class WizardValidationStep1Component implements WizardStep {

  isValid: boolean;
  stepName = 'Step 1';

  constructor() {
    this.isValid = true;
  }

  nextClicked(e) {
    alert('Clicked next on ' + this.stepName);
  }

  previousClicked(e) {
    alert('Clicked previous on ' + this.stepName);
  }
}

使用wizard-validation-step1.component.html:

<p>
  wizard-validation-step1 works!
</p>

---

在wizard.component.ts中,如果我使用无类型数组而不是WizardStep数组,它可以很好地工作,但当然我的步骤组件不会注册点击等.

@Input() steps = [];

当如上所示使用时,当我尝试运行时ng build,我收到以下消息:

ERROR in src/app/wizard-validation/wizard-validation.component.ts(20,21): error TS2345: Argument of type 'typeof WizardValidationStep1Component' is not assignable to parameter of type 'WizardStep'.
  Property 'isValid' is missing in type 'typeof WizardValidationStep1Component'.
src/app/wizard-validation/wizard-validation.component.ts(21,21): error TS2345: Argument of type 'typeof WizardValidationStep2Component' is not assignable to parameter of type 'WizardStep'.
  Property 'isValid' is missing in type 'typeof WizardValidationStep2Component'.
src/app/wizard-validation/wizard-validation.component.ts(22,21): error TS2345: Argument of type 'typeof WizardValidationStep3Component' is not assignable to parameter of type 'WizardStep'.
  Property 'isValid' is missing in type 'typeof WizardValidationStep3Component'.

我试图在Angular 5/6中使用的模式是否有效？如果没有,是否有另一种方法可以完成我想要做的事情？

Answer 1

为什么不使用图书馆呢？这个很酷

如果库不是一个选项，我将创建一个自定义步骤指令并将步骤配置切换到 html 模板。

所以，而不是

// wizard.component.ts

ngOnInit() {
  this.steps.push(WizardValidationStep1Component);
  this.steps.push(WizardValidationStep2Component);
  this.steps.push(WizardValidationStep3Component);
}

你会这样做

<!-- something-using-wizard.component.html -->

<my-wizard>
  <my-step1-component myStep [someInput]="true"></my-step1-component>
  <my-step2-component myStep [someOtherInput]="'foo'"></my-step2-component>
</my-wizard>

WizardComponent并在使用@ContentChildren()装饰器时抓住您的步骤实例

// wizard.component.ts

@ContentChildren(MyStepDirective)
public steps: QueryList<MyStepInterface>;

您可以在我链接的库的源代码中进一步激发自己的灵感。作者做了类似的事...

我希望这对你有一点帮助:-)