How to apply multiple template bindings on one ele

2019-03-08 23:00发布

This question already has an answer here:

I'm using template like following:

<ul [ngClass]="{dispN: !shwFilter,'list-group':true,'autoS':true,'dispB':shwFilter,'myshddw':true}" style=";display: none">
  <li *ngIf="itsNotF && itsNotF.length" [ngClass]="{bgDFF: !colps[j],'list-group-item':true}" *ngFor="let valm1 of itsNotF;let j=index;" (click)="togFltr(j)" style="padding: 0;background: #fff">
    <div *ngIf="valm1 && valm1.type=='1'">
      <h5 style="padding:8px;margin: 0;">{{valm1['header']}}</h5>
      <p style="margin: 8px;">{{valm1['body']}}</p>
      <h6 style="padding:8px;margin: 0;">{{valm1['note']}}</h6>
    </div>
    <div *ngIf="valm1 && valm1.type=='2'" (click)="modlTxt=valm1;notREadVu(j)" data-toggle="modal" data-target="#myModal">
      <h5 style="padding:8px;margin: 0;">{{valm1['header']}}</h5>
      <h6 style="padding:8px;margin: 0;">{{valm1['note']}}</h6>
    </div>
    <div *ngIf="valm1 && valm1.type=='3'">
      <h5 style="padding:8px;margin: 0;">{{valm1['header']}}</h5>
      <p style="margin: 8px;">{{valm1['body']}}</p>
      <h6 style="padding:8px;margin: 0;">{{valm1['note']}}</h6>
    </div>
  </li>
  <li [ngClass]="{bgDFF: !colps[j],'list-group-item':true,'lgOt':true}" (click)="logout()">
    <span class="title">Log Out <i class="fa fa-sign-out"></i></span>
  </li>
</ul>

So it gives following error:

EXCEPTION: Template parse errors:
Can't have multiple template bindings on one element. Use only one attribute named 'template' or prefixed with * ("one">
  <li *ngIf="itsNotF && itsNotF.length" [ngClass]="{bgDFF: !colps[j],'list-group-item':true}" [ERROR ->]*ngFor="let valm1 of itsNotF;let j=index;" (click)="togFltr(j)" style="padding: 0;background: #fff">
"): App@78:94

Previously it was not giving error I faced this issue after upgrading to RC4.

So what's workaround, so I can apply multiple template binding on single element without altering Template structure.

4条回答
疯言疯语
2楼-- · 2019-03-08 23:15

Put your *ngIf in a parent div, and the *ngFor can stay where it is.

For example:

<div *ngIf="itsNotF && itsNotF.length">
    <div [ngClass]="{bgDFF: !colps[j],'list-group-item':true}" *ngFor="let valm1 of itsNotF;let j=index;" (click)="togFltr(j)" style="padding: 0;background: #fff">
    </div>
</div>
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霸刀☆藐视天下
3楼-- · 2019-03-08 23:18

You can use the following (expanded version) to preserve the document structure (e.g. for your css selectors):

<template [ngIf]="itsNotF && itsNotF.length">
    <div [ngClass]="{bgDFF: !colps[j],'list-group-item':true}" *ngFor="let valm1 of itsNotF;let j=index;" (click)="togFltr(j)" style="padding: 0;background: #fff">
    </div>
</template>
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兄弟一词,经得起流年.
4楼-- · 2019-03-08 23:34

If you are using *ngFor and want to add *ngIf to check some field, if conditional is not too complicated, I use filter for that, where I run my conditional and return only items that enter in my condition inside that loop.. Hope it helps

something like that where I want to show only items with description:

<div class="delivery-disclaimer" *ngFor="let payment of cart.restaurant.payment_method | filter:[{short_name: cart.payment_method}] | onlyDescription" text-wrap>
        <ion-icon item-left name="information-circle"></ion-icon> {{payment.pivot.description}}
    </div>

davor

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5楼-- · 2019-03-08 23:41

Can't use two template binding on one element in Angular 2 (like *ngIf and *ngFor). But you can achieve the same by wrapping the element with a span or any other element. It is good to append with an <ng-container> as it is a logical container and it will not get append to the DOM. For example,

<ng-container *ngIf="condition">
    <li *ngFor="let item of items">
        {{item}}
    </li>
</ng-container>
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