Put an angular variable in an HTML attribute

Question

Question: In the below sample code, we can see that each message has a unique MessageSid. In the HTML code, I would like to set

data-target="#deleteModal" to data-target="#{{message.MessageSid}}"

and similarly

id="deleteModal" to id="{{message.MessageSid}}"

How can I do this? I would like each modal to be individual to each message.

MessageDetail Model

export class MessageDetail {
    MessageSid: string;
    Body: string;
    Time: string;
    Direction: string;
    FromPhoneNumber: string;
    ToPhoneNumber: string;
}

HTML code

  <div id="listOfMessages" class="mt-5">
    <div class="container" *ngFor="let message of messageList" [ngClass]="classDirection(message)">
      <img src="/assets/img/avatar.png" alt="Avatar">
      <p>{{message.Body}}</p>
      <button class="btn btn-danger btn-circle btn-circle-sm m-1 float-right" data-toggle="modal" data-target="#deleteModal"><i class="fa fa-times"></i></button>
      <span class="time-right">{{message.TimeCreated}}</span>

      <!-- Confirm Delete Modal -->
      <div class="modal fade" id="deleteModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
        <div class="modal-dialog modal-dialog-centered" role="document">
          <div class="modal-content">
            <div class="modal-header">
              <h5 class="modal-title">Delete Message</h5>
              <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                <span aria-hidden="true">&times;</span>
              </button>
            </div>
            <div class="modal-body">
              <p>Are you sure you want to delete this message?</p>
              <p>{{message.Body}}</p>
            </div>
            <div class="modal-footer">
              <button type="button" class="btn btn-danger" (click)="deleteMessage(message, $event)">Delete</button>
              <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
            </div>
          </div>
        </div>
      </div>
      <!-- End Confirm Delete Modal-->

    </div>
  </div>

I have tried this solution on my own. But it seems only Modals 1,4,7 in the list work. The ones in between do not pop up when clicked.

  <div id="listOfMessages" class="mt-5">
    <div class="container" *ngFor="let message of messageList" [ngClass]="classDirection(message)">
      <img src="/assets/img/avatar.png" alt="Avatar">
      <p>{{message.Body}}</p>
      <button class="btn btn-danger btn-circle btn-circle-sm m-1 float-right" data-toggle="modal" attr.data-target="#{{message.MessageSid}}"><i class="fa fa-times"></i></button>
      <span class="time-right">{{message.TimeCreated}}</span>

      <!-- Confirm Delete Modal -->
      <div class="modal fade" id="{{message.MessageSid}}" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
        <div class="modal-dialog modal-dialog-centered" role="document">
          <div class="modal-content">
            <div class="modal-header">
              <h5 class="modal-title">Delete Message</h5>
              <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                <span aria-hidden="true">&times;</span>
              </button>
            </div>
            <div class="modal-body">
              <p>Are you sure you want to delete this message?</p>
              <p>{{message.Body}}</p>
            </div>
            <div class="modal-footer">
              <button type="button" class="btn btn-danger" (click)="deleteMessage(message, $event)">Delete</button>
              <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
            </div>
          </div>
        </div>
      </div>
      <!-- End Confirm Delete Modal-->

    </div>
  </div>

Answer 1

Thank you. I figured out the issue. Some MessageSids began with numbers and apparently you cannot have a tag with an ID that begins with a number. Prefixing a character solved the issue.

Answer 2

You should do in the HTML:

...
<div [id]="'#' + message.messageSId"> </div>
...

Inside the tag you should do with [attr]="typeScriptExpression" (property binding), not with attr={{typeScriptExpression}} (interpolation)

Reference to study: https://angular.io/guide/template-syntax