指令升级到Angular 9后无法与FormControl一起使用 [英] Directives not working with FormControl after upgrading to Angular 9
问题描述
我使用了用于启用和禁用表格的指令.这是在单独的打字稿文件中.代码如下:-
I have used directives for enabling and disabling forms. This is in a separate typescript file. Code is given below: -
import { NgControl } from '@angular/forms';
import { Directive, Input } from '@angular/core';
@Directive({
selector: '[disableControl]'
})
export class DisableControlDirective {
@Input('disableControl') set disableControl( condition : boolean ) {
const action = condition ? 'disable' : 'enable';
this.ngControl.control[action]();
}
constructor (private ngControl : NgControl){}
}
HTML:-
<div class="card" *ngIf="commentsFormEnable">
<div class="card">
<h3 class="mb-0">
<button class="btn btn-primary btn-sm" aria-expanded="false">
Comments
</button>
</h3>
<form [formGroup]="commentsForm" data-target="comments" id="commentsForm" (ngSubmit)="onSubmit($event)">
<div class="row">
<div class="col">
<div class="input-group mb-3">
<div class="input-group-prepend">
<span class="input-group-text">Comments</span>
</div>
<textarea formControlName="comment" class="form-control" [disableControl]="comments" placeholder="Add a comment."></textarea>
</div>
</div>
</div>
<div class="row">
<div class="col text-right">
<ng-container *ngIf="comments; else commentsbtnElseBlock">
<ng-container *ngTemplateOutlet="params;context:{btnId: 'comments', toggleValue: comments}"></ng-container>
</ng-container>
<ng-template #commentsbtnElseBlock>
<ng-container *ngTemplateOutlet="paramsElse;context:{btnId: 'comments', toggleValue: comments}"></ng-container>
</ng-template>
</div>
</div>
<div class="row">
<div class="col">
<div *ngFor="let commentData of commentsList; let i=index">
<div class="comment-list">
<div class="user-initial border rounded-circle">
{{commentData.UpdatedBy | slice:0:1}}
</div>
<div class="comment-info">
<ul>
<li class="ml-2 mr-2">
<span class="user-name">{{commentData.UpdatedBy}}</span>
</li>
<li>
<span>
<small>commented {{commentData.UpdatedDate | date:'medium'}}</small>
</span>
<!-- <i input type="checkbox" class="fas fa-trash-alt" id="{{commentData.RecordId}}" (change)=onChange($event) (click)="deleteCommentsEntity(i,project.ProjectId)"></i>-->
</li>
</ul>
</div>
<div class="ml-5 mb-5">
{{commentData.Comment}}
<!--<div class="project-desc" style="text-align:left; width:3080px">
<app-inline-edit [(ngModel)]=commentData.Comment label=commentData.Comment [required]="true" type="input" style="width:300px">
</app-inline-edit>
</div>-->
<button class="btn btn-pill btn-primary btn-sm mr-2" style="text-align:right;color:Tomato;margin-right:20px;float:right" type="button">
<i ng-mouseover="count = count + 1" ng-init="count=0" ng-show="Delete" id="{{commentData.RecordId}}" class="fas fa-trash-alt" style="text-align:right;" (click)="deleteCommentsEntity(commentData.RecordId,project.ProjectId)"></i>
</button>
</div>
</div>
</div>
</div>
</div>
</form>
</div>
</div>
我在这里担心的是，上面的代码可与以下软件包一起使用:-
My concern here is that the above code works with below packages: -
"@angular/animations": "^8.0.2",
"@angular/common": "^8.0.2",
"@angular/compiler": "^8.0.2",
"@angular/core": "^8.0.2",
"@angular/forms": "^8.0.2",
"@angular/http": "^8.0.0-beta.10",
"@angular/platform-browser": "^8.0.2",
"@angular/platform-browser-dynamic": "^8.0.2",
"@angular/platform-server": "^8.2.11",
"@angular/router": "^8.0.2",
并且不能使用:-
"@angular/animations": "^9.0.0-rc.12",
"@angular/common": "^9.0.0-rc.12",
"@angular/compiler": "^9.0.0-rc.12",
"@angular/core": "^9.0.0-rc.12",
"@angular/forms": "^9.0.0-rc.12",
"@angular/platform-browser": "^9.0.0-rc.12",
"@angular/platform-browser-dynamic": "^9.0.0-rc.12",
"@angular/platform-server": "^8.2.11",
"@angular/router": "^9.0.0-rc.12",
我收到此错误-
无法读取位于以下位置的未定义属性"disabled" DisableControlDirective.set无法读取以下属性的禁用" 未定义
cannot read property 'disabled' of undefined at DisableControlDirective.set cannot read property 'disable' of undefined
版本升级可能有问题吗?我无能为力.请提出是否有解决此问题的方法.
Could it be a problem with the version upgrade? I am clueless. Please suggest if there is any way to resolve this issue.
推荐答案
由于某种原因，注入角度9的ngControl无法正常工作，因为它正在角度8中工作 解决方法是，您可以将 this.ngControl.controlaction 包装在setTimeout中
For some reason angular 9 injected ngControl is not working as it's was working in angular 8, As a Workaround you can wrap this.ngControl.controlaction inside setTimeout
尝试一下:
import { NgControl } from '@angular/forms';
import { Directive, Input } from '@angular/core';
@Directive({
selector: '[disableControl]'
})
export class DisableControlDirective {
@Input('appDisable') set disableControl( condition : boolean ) {
const action = condition ? 'disable' : 'enable';
setTimeout(()=>{
this.ngControl.control[action]();
});
}
constructor (private ngControl : NgControl){}
}
或
您可以通过侦听ngOnChanges之类的绑定更改来解决此问题
You can fix this issue by listening binding change inside ngOnChanges like this
@Input('appDisable') disableControl;
ngOnChanges(changes) {
if (changes['disableControl']) {
const action = this.opDisabled ? 'disable' : 'enable';
this.ngControl.control[action]();
}
}
这篇关于指令升级到Angular 9后无法与FormControl一起使用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
