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Angular2 RC5:无法绑定到“属性 X”,因为它不是“子组件”的已知属性

我有一个基于 Angular2 Seed 项目的小型 Angular2 项目,我正在尝试升级到 Angular2 RC5。

我的项目有一些功能,其中之一称为 home。 Home 组件使用一个名为 create-report-card-form 的子组件。我已经在 home.module 中声明了 home 和 create-report-card-form 组件(请参见下面的代码)并得到这个 错误

未处理的承诺拒绝:模板解析错误:无法绑定到“currentReportCardCount”,因为它不是“create-report-card-form”的已知属性。如果“create-report-card-form”是一个 Angular 组件并且它有“currentReportCardCount”输入,那么验证它是这个模块的一部分。

项目结构

-app
    - app.module.ts
    - app.component.ts
    - +home
        - home.module.ts 
        - home.component.ts
        - home.component.html
        - create-report-card-form.component.ts
        - create-report-card-form.component.html
    - +<other "features">
    - shared
        - shared.module.ts

home.module

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import {ReactiveFormsModule} from '@angular/forms';

import { SharedModule } from '../shared/shared.module';
import { DataService } from '../shared/services/index';
import { HomeComponent } from './home.component';
import { CreateReportCardFormComponent } from './create-report-card-form.component';

@NgModule({
    imports: [CommonModule, SharedModule, ReactiveFormsModule],
    declarations: [HomeComponent, CreateReportCardFormComponent],
    exports: [HomeComponent, CreateReportCardFormComponent],
    providers: [DataService]
})

export class HomeModule { }

应用程序模块

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { APP_BASE_HREF } from '@angular/common';
import { RouterModule } from '@angular/router';
import { HttpModule } from '@angular/http';
import { AppComponent } from './app.component';
import { routes } from './app.routes';

import { AboutModule } from './+about/about.module';
import { HomeModule } from './+home/home.module';
import {TestModule} from './+test/test.module';
import {VoteDataEntryModule} from './+vote-data-entry/vote-data-entry.module';
import { SharedModule } from './shared/shared.module';

@NgModule({
  imports: [BrowserModule, HttpModule, RouterModule.forRoot(routes), AboutModule, HomeModule,
    TestModule, VoteDataEntryModule, SharedModule.forRoot()],
  declarations: [AppComponent],
  providers: [{
    provide: APP_BASE_HREF,
    useValue: '<%= APP_BASE %>'
  }],
  bootstrap: [AppComponent]

})

export class AppModule { }

创建报告卡form.component.ts

import { Component, Input, Output, EventEmitter, OnInit} from '@angular/core';
import { FormBuilder, FormGroup, FormControl } from '@angular/forms';
// import { Dialog, Dropdown, SelectItem, Header, Footer, Messages, Message } from 'primeng/primeng';
import { SelectItem, Message } from 'primeng/primeng';

import {ReportCard, ReportCardDataSource} from '../shared/index';
import {CREATE_REPORT_CARD_FORM_HEADING, EDIT_REPORT_CARD_FORM_HEADING} from './constants';

@Component({
    moduleId: module.id,
    selector: 'create-report-card-form',
    templateUrl: 'create-report-card-form.component.html'
})
export class CreateReportCardFormComponent implements OnInit {

    @Input() public reportCardDataSourcesItems: SelectItem[];
    @Input() public reportCardYearItems: SelectItem[];
    @Input() errorMessages: Message[];

    @Output() reportCardCreated = new EventEmitter<ReportCard>();
    @Output() editReportCardFormValueChanged = new EventEmitter<ReportCard>();

    public editReportCardForm: FormGroup;
    private selectedReportCardDataSourceIdControl: FormControl;
    private selectedReportCardYearControl: FormControl;

    // TODO: remove this hack for resetting the angular 2 form once a real solution is available (supposedly in RC5)
    private isFormActive: boolean = true;
    private formHeaderString: string = CREATE_REPORT_CARD_FORM_HEADING;
    private formDialogVisible: boolean = false;
    private isCreatingNewReportCard = false;  // false implies that we are updating an existing report card

    constructor(private fb: FormBuilder) {
    }

    configureForm(selectedReportCard: ReportCard, createNewReport: boolean) {
        this.isCreatingNewReportCard = createNewReport;

        this.resetForm();

        this.selectedReportCardDataSourceIdControl.updateValue(selectedReportCard.reportCardDataSource.reportCardSourceId);

        this.selectedReportCardYearControl.updateValue(selectedReportCard.reportCardYear);

        if (createNewReport) {
            this.formHeaderString = CREATE_REPORT_CARD_FORM_HEADING;
        } else {
            // updating an existing report card
            this.formHeaderString = EDIT_REPORT_CARD_FORM_HEADING +
                selectedReportCard.reportCardYear + ' ' + selectedReportCard.reportCardDataSource.reportCardSourceName;
        }

        this.editReportCardForm.valueChanges.subscribe(data => this.onFormValueChanged(data));
    }

    customGroupValidator(reportCardDataSourceIdControl: FormControl, reportCardYearControl: FormControl,
        isCreatingNewReportCard: boolean) {
        return (group: FormGroup): { [key: string]: any } => {

            // missing data error ...
            if (!reportCardDataSourceIdControl.value || !reportCardYearControl.value) {
                return { 'requiredDataError': 'Report card year AND provider must be selected.' };
            }

            // invalid data error ...
            if (isCreatingNewReportCard) {
                if (!reportCardDataSourceIdControl.touched || !reportCardYearControl.touched) {
                    return { 'requiredDataError': 'Report card year AND provider must be selected.' };
                }
            } else {
                if (!reportCardDataSourceIdControl.touched && !reportCardYearControl.touched) {
                    return { 'requiredDataError': 'Report card year OR provider must be selected.' };
                }
            }

            // return null to indicate the form is valid
            return null;
        };
    }

    hideFormDialog() {
        this.formDialogVisible = false;
    }

    showFormDialog() {
        // hide any previous errors
        this.errorMessages = [];
        this.formDialogVisible = true;
    }

    createForm() {
        // by default, configure the form for new report card creation by setting
        // the initial values of both dropdowns to empty string
        this.selectedReportCardDataSourceIdControl = new FormControl('');
        this.selectedReportCardYearControl = new FormControl('');

        this.editReportCardForm = this.fb.group({
            selectedReportCardDataSourceIdControl: this.selectedReportCardDataSourceIdControl,
            selectedReportCardYearControl: this.selectedReportCardYearControl
        }, {
                validator: this.customGroupValidator(this.selectedReportCardDataSourceIdControl, this.selectedReportCardYearControl,
                    this.isCreatingNewReportCard),
                asyncValidator: this.duplicateReportCardValidator.bind(this)
            });
    }

    duplicateReportCardValidator() {
        return new Promise(resolve => {

            if ((this.errorMessages) && this.errorMessages.length === 0) {
                resolve({ uniqueReportCard: true });
            } else {
                resolve(null);
            }
        });
    }

    showError(errorMessages: Message[]) {
        this.errorMessages = errorMessages;
    }

    ngOnInit() {
        this.createForm();
    }

    onEditReportCardFormSubmitted() {

        let newReportCard = this.getReportCard(
            this.selectedReportCardDataSourceIdControl.value,
            this.selectedReportCardYearControl.value,
            this.reportCardDataSourcesItems
        );

        this.reportCardCreated.emit(newReportCard);
    }

    resetForm() {
        this.createForm();
        this.isFormActive = false;
        setTimeout(() => this.isFormActive = true, 0);
    }

    onFormValueChanged(data: any) {
        let newReportCard = this.getReportCard(
            this.selectedReportCardDataSourceIdControl.value,
            this.selectedReportCardYearControl.value,
            this.reportCardDataSourcesItems
        );

        this.editReportCardFormValueChanged.emit(newReportCard);
    }

    private getReportCard(reportCardDataSourceIdString: string, reportCardYearString: string,
        reportCardDataSourceItems: SelectItem[]): ReportCard {

        let selectedReportCardYear: number = Number(reportCardYearString);
        let selectedProviderReportCardId: number = Number(reportCardDataSourceIdString);

        let selectedProviderReportCardName: string = 'Unknown Report Card';

        for (var i = 0; i < this.reportCardDataSourcesItems.length; i++) {
            var element = this.reportCardDataSourcesItems[i];
            if (Number(element.value) === selectedProviderReportCardId) {
                selectedProviderReportCardName = element.label;
                break;
            }
        }

        let reportCard: ReportCard = new ReportCard();

        reportCard.reportCardYear = selectedReportCardYear;

        reportCard.reportCardDataSource = new ReportCardDataSource(
            selectedProviderReportCardId,
            selectedProviderReportCardName
        );

        return reportCard;
    }
}

创建报告卡form.component.html

<p-dialog header={{formHeaderString}} [(visible)]="formDialogVisible" [responsive]="true" showEffect="fade "
    [modal]="true" width="400">
    <form *ngIf="isFormActive" [formGroup]="editReportCardForm" (ngSubmit)="onEditReportCardFormSubmitted()">
        <div class="ui-grid ui-grid-responsive ui-fluid " *ngIf="reportCardDataSourcesItems ">
            <div class="ui-grid-row ">
                <p-dropdown [options]="reportCardDataSourcesItems" formControlName="selectedReportCardDataSourceIdControl" [autoWidth]="true"></p-dropdown>
            </div>
            <div class="ui-grid-row ">
                <p-dropdown [options]="reportCardYearItems" formControlName="selectedReportCardYearControl" [autoWidth]="true"></p-dropdown>
            </div>
            <div class="ui-grid-row ">
                <p-messages [value]="errorMessages"></p-messages>
            </div>
            <footer>
                <div class="ui-dialog-buttonpane ui-widget-content ui-helper-clearfix ">
                    <button type="submit" pButton icon="fa-check " 
                    [disabled]="!editReportCardForm?.valid" label="Save "></button>
                </div>
            </footer>
        </div>
    </form>
</p-dialog>

home.component.ts

import { Component, OnInit, ViewChild } from '@angular/core';
// // import { REACTIVE_FORM_DIRECTIVES } from '@angular/forms';
// import {ROUTER_DIRECTIVES} from '@angular/router';
// import { InputText, Panel, SelectItem, Message, Growl, Dialog, DataTable, Column, Header, Footer, Tooltip } from 'primeng/primeng';
import { Message, SelectItem } from 'primeng/primeng';

import {CreateReportCardFormComponent} from './create-report-card-form.component';
import { ReportCardDataSource, ReportCard, ProviderData, DataService,
   DUPLICATE_REPORT_CARD_MESSAGE } from '../shared/index';
import {ReportCardCommands} from './enums';

/**
 * This class represents the lazy loaded HomeComponent.
 */
@Component({
  moduleId: module.id,
  selector: 'sd-home',
  templateUrl: 'home.component.html',
  styleUrls: ['home.component.css']
  //,directives: [CreateReportCardFormComponent]
})

export class HomeComponent implements OnInit {

  public growlMessages: Message[] = [];
  public createReportCardError: Message[] = [];
  public reportCardDataSourcesItems: SelectItem[] = [{ label: 'Select Provider', value: '' }];
  public reportCardYearItems: SelectItem[] = [{ label: 'Select Year', value: '' }];
  public providerData: ProviderData = new ProviderData();
  public displayReportCardDeleteConfirmation: boolean = false;

  private isCreatingNewReportCard: boolean = true;
  private selectedReportCard: ReportCard;

  @ViewChild(CreateReportCardFormComponent)
  private createReportCardFormComponent: CreateReportCardFormComponent;

  constructor(private dataService: DataService) { }

  ngOnInit() {
    let reportCardDataSources: ReportCardDataSource[] = this.dataService.getReportCardDataSources();

    for (var i = 0; i < reportCardDataSources.length; i++) {
      var element = reportCardDataSources[i];
      this.reportCardDataSourcesItems.push({ label: element.reportCardSourceName, value: element.reportCardSourceId });

      // retrieve data from localStorage if available
      this.providerData = this.dataService.getProviderData();
    }

    // initialize report card years
    const minYear: number = 2000;
    // TODO: maxYear should be sourced from the server by a service
    let maxYear: number = (new Date()).getFullYear();

    for (var i = maxYear; i >= minYear; i--) {
      this.reportCardYearItems.push({ value: i.toString(), label: i.toString() });
    }
  }

  // Returns the index of the report card in providerData.reportCards that has the same reporCardSourceId
  // and reportCardYear as selectedReportCard, or -1 if there is no match.
  indexOf(selectedReportCard: ReportCard): number {
    return this.providerData.reportCards.findIndex(x =>
      x.reportCardDataSource.reportCardSourceId === selectedReportCard.reportCardDataSource.reportCardSourceId &&
      x.reportCardYear === selectedReportCard.reportCardYear);
  }

  onReportCardCreated(newReportCard: ReportCard) {
    if (newReportCard) {

      if ((this.indexOf(newReportCard) > -1)) {
        // attemp to create a duplicate report card; show error
        this.setCreateReportCardFromErrorMessage(DUPLICATE_REPORT_CARD_MESSAGE);
      } else {
        if (this.isCreatingNewReportCard) {
          // save new report card
          this.createReportCardError = [];
          this.createReportCardFormComponent.hideFormDialog();
          this.providerData.reportCards.splice(0, 0, newReportCard);

          this.createReportCardFormComponent.hideFormDialog();

        } else {
          // update existing report card
          let reportCardToUpdateIndex: number = this.indexOf(this.selectedReportCard);

          if (reportCardToUpdateIndex > -1) {
            this.providerData.reportCards[reportCardToUpdateIndex].reportCardDataSource.reportCardSourceId
              = newReportCard.reportCardDataSource.reportCardSourceId;
            this.providerData.reportCards[reportCardToUpdateIndex].reportCardDataSource.reportCardSourceName
              = newReportCard.reportCardDataSource.reportCardSourceName;
            this.providerData.reportCards[reportCardToUpdateIndex].reportCardYear
              = newReportCard.reportCardYear;
          }
        }
        this.dataService.storeProviderData(this.providerData);
        this.isCreatingNewReportCard = true;
        this.clearCreateReportCardFormErrorMessage();
        this.createReportCardFormComponent.hideFormDialog();
      }
    }
  }

  editReportCardFormValueChanged(newReportCard: ReportCard) {
    if (this.indexOf(newReportCard) === -1) {
      // clear duplicate report card error message in 'create report card' dialog
      this.clearCreateReportCardFormErrorMessage();
    } else {
      // set duplicate report card error message
      this.setCreateReportCardFromErrorMessage(DUPLICATE_REPORT_CARD_MESSAGE);
    }
  }

  onAddReportCardButtonClicked() {
    this.isCreatingNewReportCard = true;
    this.createReportCardFormComponent.configureForm(new ReportCard(), this.isCreatingNewReportCard);
    this.createReportCardFormComponent.showFormDialog();
  }

  onReportCardDeleteButtonClicked(reportCard: ReportCard) {
    this.reportCardCommandExecute(reportCard, ReportCardCommands.Delete);
  }

  onReportCardEditButtonClicked(reportCard: ReportCard) {
    this.reportCardCommandExecute(reportCard, ReportCardCommands.EditReportCard);
  }

  onAddVotesRouterLinkClicked(reportCard: ReportCard) {
    this.reportCardCommandExecute(reportCard, ReportCardCommands.EditVotes);
  }

  onReportCardDeleteConfirmButtonClick(isDeleteOk: boolean) {
    if (isDeleteOk) {
      this.providerData.reportCards.splice(this.providerData.selectedReportCardIndex, 1);
      // store updated reportCards in local storage
      this.dataService.storeProviderData(this.providerData);
    }
    this.displayReportCardDeleteConfirmation = false;
  }

  reportCardCommandExecute(reportCard: ReportCard, command: ReportCardCommands) {
    this.providerData.selectedReportCardIndex = this.indexOf(reportCard);
    this.selectedReportCard = reportCard;

    switch (command) {
      case ReportCardCommands.EditVotes:
        this.dataService.storeProviderData(this.providerData);
        break;
      case ReportCardCommands.Delete:
        this.displayReportCardDeleteConfirmation = true;
        break;
      case ReportCardCommands.EditReportCard:
        this.isCreatingNewReportCard = false;
        this.createReportCardFormComponent.configureForm(reportCard, this.isCreatingNewReportCard);
        this.createReportCardFormComponent.showFormDialog();
        break;
      default:
        break;
    }
  }

  private setCreateReportCardFromErrorMessage(message: Message) {
    this.createReportCardError = [];
    this.createReportCardError.push(message);

    this.createReportCardFormComponent.showError(this.createReportCardError);
  }

  private clearCreateReportCardFormErrorMessage() {
    this.createReportCardError = [];
    this.createReportCardFormComponent.showError(this.createReportCardError);
  }
}

home.component.html

<p-growl [value]="growlMessages" sticky="sticky"></p-growl>
<p-dataTable [value]="providerData.reportCards" [paginator]="true" rows="15" [responsive]="true">
  <header>
    <div>
      <h1>Report Cards ({{providerData.reportCards.length}})</h1>
    </div>
    <button type="button" pButton icon="fa-plus" (click)="onAddReportCardButtonClicked()" label="Add" title="Add new report card"></button>
  </header>
  <p-column styleClass="col-button">
    <template let-reportCard="rowData">
      <button type="button" pButton (click)="onReportCardEditButtonClicked(reportCard)" icon="fa-pencil" title="Edit report card"></button>
    </template>
  </p-column>
  <p-column field="reportCardDataSource.reportCardSourceName" header="Report Card" [sortable]="true"></p-column>
  <p-column field="reportCardYear" header="Year" [sortable]="true"></p-column>
  <p-column header="Votes" [sortable]="false">
    <template let-reportCard="rowData">
      {{reportCard.votes.length}}
      <!--<button type="button" pButton icon="fa-pencil-square" (click)="editVotes(reportCard)" title="Edit votes"></button>-->
      <a [routerLink]="['/votes']" (click)="onAddVotesRouterLinkClicked(reportCard)">Edit</a>
    </template>
  </p-column>
  <p-column styleClass="col-button">
    <template let-reportCard="rowData">
      <button type="button" pButton (click)="onReportCardDeleteButtonClicked(reportCard)" icon="fa-trash" title="Delete report card"></button>
    </template>
  </p-column>
</p-dataTable>

<create-report-card-form [currentReportCardCount]="providerData.reportCards.length" [reportCardDataSourcesItems]="reportCardDataSourcesItems"
  [reportCardYearItems]="reportCardYearItems" (reportCardCreated)=onReportCardCreated($event) (editReportCardFormValueChanged)=editReportCardFormValueChanged($event)>
</create-report-card-form>

<p-dialog header="Confirm Deletion" [(visible)]="displayReportCardDeleteConfirmation" modal="modal" showEffect="fade">
  <p>
    Delete the following report card and all related data (<strong>NO undo</strong>)?
  </p>
  <p>
    <strong>{{providerData?.reportCards[providerData.selectedReportCardIndex]?.reportCardDataSource?.reportCardSourceName}}</strong><br/>
    <strong>{{providerData?.reportCards[providerData.selectedReportCardIndex]?.reportCardYear}}</strong>
  </p>
  <footer>
    <div class="ui-dialog-buttonpane ui-widget-content ui-helper-clearfix">
      <button type="button" pButton icon="fa-close" (click)="onReportCardDeleteConfirmButtonClick(false)" label="No"></button>
      <button type="button" pButton icon="fa-check" (click)="onReportCardDeleteConfirmButtonClick(true)" label="Yes"></button>
    </div>
  </footer>
</p-dialog>
您应该包含来自 create-report-card-form.component.ts 的代码
@Isaac - 添加了来自 create-report-card-form.component.ts 的代码
你也可以发布模板吗?该错误告诉您 create-report-card-form 模板或父组件正在尝试绑定或访问 CreateReportCardFormComponent 组件上似乎不存在的“currentReportCardCount”属性。
@AndrewBabin - 为父组件和子组件添加了代码和模板。

A
ABabin
<create-report-card-form [currentReportCardCount]="providerData.reportCards.length" ...
                         ^^^^^^^^^^^^^^^^^^^^^^^^

在您的 HomeComponent 模板中,您尝试绑定到 CreateReportCardForm 组件上不存在的输入。

在 CreateReportCardForm 中,这些是您仅有的三个输入:

@Input() public reportCardDataSourcesItems: SelectItem[];
@Input() public reportCardYearItems: SelectItem[];
@Input() errorMessages: Message[];

为 currentReportCardCount 添加一个,你应该很高兴。


谢谢!为 currentReportCardCount 添加 @Input() 解决了这个问题。我的错误是假设代码是正确的,只是因为它在 RC4 及之前的版本中工作。
此外,如果您的组件是共享模块。确保将其添加到 @NgModule 声明和导出数组中。
@ABabin 我有同样的问题,但有关更多信息,您可以在此处查看:stackoverflow.com/questions/66429902/… 我想知道是否有人可以帮助我..
H
Houman

我通过添加前缀 (attr.) 来修复它:

<create-report-card-form [attr.currentReportCardCount]="expression" ...

不幸的是,这还没有正确记录。

更详细here


不要这样做。它将阻止该属性被传递给嵌套指令。
@igasparetto 在这种情况下,您可能没有嵌套指令
在将非标准属性添加到按钮标签时,我遇到了同样的问题,我可以通过这样做来解决它。谢谢你。
C
Caner

此错误有多种可能的原因:

1)当你把属性'x'放在括号内时,你试图绑定到它。因此,首先要检查的是是否在您的组件中使用 Input() 装饰器定义了属性“x”

你的 html 文件:

<body [x]="...">

你的类文件:

export class YourComponentClass {

  @Input()
  x: string;
  ...
}

(确保你也有括号)

2) 确保你在 NgModule 中注册了你的组件/指令/管道类:

@NgModule({
  ...
  declarations: [
    ...,
    YourComponentClass
  ],
  ...
})

有关声明指令的更多详细信息,请参阅 https://angular.io/guide/ngmodule#declare-directives

3)如果您的角度指令中有错字,也会发生这种情况。例如:

<div *ngif="...">
     ^^^^^

代替:

<div *ngIf="...">

发生这种情况是因为在幕后角度将星号语法转换为:

<div [ngIf]="...">

救生员。我无法收到该错误消息。问题是我没有在模块中注册我的子组件。
发生此错误的另一个原因是当您想为组件使用属性选择器但忘记选择器中的括号时。示例:您想这样做:<tr my-component></tr> 但在 @Component 中您这样做 selector: 'my-component' 而不是 selector: '[my-component]'...
是的 - 该错误消息可能会产生误导 - 我赞成这个答案,因为它在一般情况下更彻底地回答了这个问题。具体来说,#2 根本不直观,因为错误“无法绑定到‘属性 X’,因为它不是‘子组件’的已知属性” - 所以这是一个有用的提示来追踪它。
A
Alf Moh

如果您使用 Angular CLI 创建组件,比如说 CarComponent,它将 app 附加到选择器名称(即 app-car),当您引用组件时会引发上述错误在父视图中。因此,您要么必须将父视图中的选择器名称更改为 <app-car></app-car>,要么将 CarComponent 中的选择器更改为 selector: 'car'


有趣的是小事最能咬你
这个问题我找了很久的答案!你简单地解决了这个问题!它工作正常!谢谢!
p
peterh

当我忘记在我的 NgModule 中声明我的自定义组件时,我遇到了同样的错误 - 检查那里,如果其他解决方案不适合您。


r
raj lanjewar
*Parent component:*
step 1:
-app.component.ts (parent class file)
export class AppComponent {
  name = "Bruce Waine";
}
-app.component.html (parent template file)
<app-child [data]="name"></app-child>   /*<app-child> is child component selector*/

*Child Component:*
step 2:child.component.ts(child component class file)
--parent input
import { Component, OnInit, Input } from '@angular/core';
export class ChildComponent implements OnInit {
  **@Input() data: any;**

  constructor() { }

  ngOnInit(): void {
  }

}

-child.component.html(child component template file)
<p>{{data}}</p>