Angular: 在更改时禁用字段并设置字段值

Question

我有一个 table，我需要在其中呈现数据库值，然后在用户更改后我需要提交该表单。这里是demo

我需要像这样申请，如果状态为 'eliminated' 或 'absent'，则需要禁用排名下拉菜单，排名将为 null/0.

我能够呈现详细信息并尝试更改状态以禁用排名，但它不起作用。

请多多指教。谢谢

Ts

import { Component } from '@angular/core';
import {
  AbstractControl,
  FormArray,
  FormBuilder,
  FormControl,
  FormGroup,
  Validators,
} from '@angular/forms';
import { merge } from 'rxjs';
import { takeWhile, tap } from 'rxjs/operators';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
})
export class AppComponent {
  name = 'Angular';
  myForm!: FormGroup;
  rankArray = [];
  rankStatusArray: any = [
    { id: 'participated', name: 'Participated' },
    { id: 'eliminated', name: 'Eliminated' },
    { id: 'absent', name: 'Absent' },
  ];
  checklist = [
    {
      id: 13,
      rank: 3,
      horse_id: 86,
      horse_name: 'test232 fdfgdg',
      life_number: null,
      country: 'Afghanistan',
      result_status: 'participated',
      comment: 'my comment',
    },
    {
      id: 12,
      rank: null,
      horse_id: 87,
      horse_name: 'test horse',
      life_number: '234234',
      country: 'Algeria',
      result_status: null,
      comment: null,
    },
    {
      id: 11,
      rank: null,
      horse_id: 88,
      horse_name: 'tesdfs',
      life_number: null,
      country: 'Afghanistan',
      result_status: null,
      comment: null,
    },
    {
      id: 10,
      rank: null,
      horse_id: 94,
      horse_name: 'nam horse',
      life_number: 'fh345',
      country: 'India',
      result_status: null,
      comment: null,
    },
  ];

  constructor(private fb: FormBuilder) {
    this.myForm = this.fb.group({
      checklist: this.fb.array([]),
    });
    this.populate();
  }

  ngOnInit(): void {
    this.rankArray = Array(4)
      .fill(1)
      .map((x, i) => i + 1);
  }

  get formChecklist() {
    return this.myForm.get('checklist') as FormArray;
  }

  populate() {
    this.checklist.forEach((x) => {
      this.formChecklist.push(
        this.fb.group({
          participantId: x.id,
          rankStatus: x.result_status,
          rank: x.rank,
          comment: x.comment,
          horse_name: x.horse_name,
          country: x.country,
          life_number: x.life_number,
        })
      );
    });
  }

  onChange(event) {
    console.log(event);
    if (event == 'eliminated' || event == 'absent') {
      this.myForm.controls['rank'].disable();
    } else {
      this.myForm.controls['rank'].enable();
    }
  }

  onSubmit() {
    console.log(this.myForm.value);
  }
}

HTML

<div class="table-responsive competition_wrapper">
  <form [formGroup]="myForm" (ngSubmit)="onSubmit()">
    <table
      class="
        bordered
        border-top-0
        table
        dark
        shadow_none
        w-100
        mb-3
        competition_result_table
      "
    >
      <thead>
        <tr>
          <th width="150" colspan="6">Competition Name</th>
        </tr>
      </thead>
      <tbody formArrayName="checklist">
        <tr class="table_sub_heading">
          <td>Status</td>
          <td>Rank</td>
          <td>Participant Name</td>
          <td>Country</td>
          <td>Life Number</td>
          <td>Comment</td>
        </tr>
        <tr
          *ngFor="let item of formChecklist.controls; let i = index"
          [formGroupName]="i"
        >
          <td>
            <div class="select_wrapper form-group mb-0">
              <select
                class="form-control"
                formControlName="rankStatus"
                (ngModelChange)="onChange($event)"
              >
                <option [ngValue]="null">Select</option>
                <option
                  *ngFor="let status of rankStatusArray"
                  [ngValue]="status.id"
                >
                  {{ status.name }}
                </option>
              </select>
            </div>
          </td>
          <td>
            <div class="select_wrapper form-group mb-0">
              <select class="form-control" formControlName="rank">
                <option value="null">Select</option>
                <option *ngFor="let rankno of rankArray" [value]="rankno">
                  {{ rankno }}
                </option>
              </select>
            </div>
          </td>
          <td>{{ item.get('horse_name').value }}</td>
          <td>
            {{ item.get('country').value }}
          </td>
          <td>
            {{ item.get('life_number').value }}
          </td>
          <td>
            <div class="form-group mb-0">
              <textarea
                type="text"
                class="form-control"
                formControlName="comment"
              ></textarea>
            </div>
          </td>
        </tr>
      </tbody>
    </table>
    <button class="btn">Add Result</button>
  </form>
</div>

<pre>{{ myForm.value | json }}</pre>

Answer 1

您列举了很多要点，因为这不是免费的代码提供程序应用程序，所以至少在您尝试做一些事情之前，我不会解决所有问题。

也就是说，我创建了一个 demo 来解决第一个问题，我看到您尝试过但无法完成。您无法禁用排名字段，因为：

首先，您在 onchange 函数中传递的事件不是您想要的。您需要事件的价值，即便如此，您还需要提取对您来说很重要的信息，即 ID。
其次，您正在尝试 disable/enable 一些不存在的东西。控制台给你关于它的错误。 this.myForm.controls['rank'] 未定义。

关于第 n.4 步，您可能需要收听排名 formcontrol 并从下一个竞争对手的排名下拉列表中隐藏所选选项。希望这能给你解决问题的提示。

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