在Angular 4中取消选中复选框时，如何从JSON数组中删除对象？

Question

0:
CategoryId: "31b7a227-9fda-4d14-8e1f-1dee5beeccb4"
Code: "GMA0300"
Description: "PA-5215: Renamed"
Enabled: true
Favorite: false
Id: "26cfdb68-ef69-4df0-b4dc-5b9c6501b0dd"
InstrumentType: null
Moniker: "1GMA0300"
Name: "Celiac Disease Panel (tTG IgG, tTG IgA, DGP IgG)"
Tests: Array(3)
  0:
   Code: "GMA0304"
   Id: "e2bb4607-c227-4483-a3e9-55c1bc5a6781"
   Name: "Deamidated Gliadin Peptide (DGP) IgG"
 __proto__: Object
  1: {Id: "2fcd610f-d453-4c4f-a8dc-1a5f50e88548", Code: "GMA0301", Name: 
 "Tissue Transglutaminase (tTG) IgA"}
  2: {Id: "de41b236-4866-419a-a6f4-5f7c1440d30f", Code: "GMA0302", Name: 
 "Tissue Transglutaminase (tTG) IgG"}
 length: 3
 __proto__: Array(0)
 TestsSelectable: false

嘿，这是一个数组selectedPanels对象，它有另一个对象数组，我已经在面板和面板中映射了它有复选框和测试，这是一个数组是可扩展的行，也有复选框

当我检查面板复选框时，它检查测试的所有子复选框，并显示测试的长度说3但是当我点击每个测试它应该是从测试长度减去说3 - 1 = 2它现在应该显示2但是当我当我取消选择每个测试复选框时，使用splice它将删除整行，或者当我点击每个测试时它取消选择父面板复选框，我也不知道当我取消选择每个测试时应该是什么不删除文本但减少数组的长度

你可以从那个图像看到

图片

这是我的html文件

<label class="custom-control custom-checkbox">
    <input type="checkbox" class="custom-control-input" [name]="panel.Id + '-' + panel.Moniker" [ngModel]="checkAllTestsSelected(panel)"
      (ngModelChange)="onPanelCheckboxUpdate($event, panel)" [id]="panel.Id + '-' + panel.Moniker">
    <span class="custom-control-indicator"></span>
  </label>

 </ng-template>
 <ng-template ngbPanelContent>
<div class="individual-panel" *ngFor="let test of panel.Tests">
  <span class="text-dimmed">{{test.Name}}</span>
  <span *ngIf="panel.Name.includes('ENA') || panel.Name.includes('Celiac')">
  <label class="custom-control custom-checkbox">
    <input type="checkbox" class="custom-control-input" [name]="test.Id + '-' + test.Code"
           [ngModel]="testSelectionSession.SelectedPanelIds.indexOf(panel.Id) > -1 || testSelectionSession.SelectedPanelIds.indexOf(test.AssociatedPanel?.Id) > -1"
           (ngModelChange)="onTestCheckboxUpdate($event, test, panel)" [id]="test.Id + '-' + test.Code">
    <span class="custom-control-indicator"></span>
  </label>
  </span>
</div>

ts文件

checkAllTestsSelected(panel: TestOrderPanel) {
  // get all individual test panels
  let individualTestPanelIds = panel.Tests.reduce((acc, test) => {
   if (test.AssociatedPanel) {
    acc.push(test.AssociatedPanel.Id);
  }
  return acc;
}, []);

// check if all individual test panels are selected
let allIndividualTestsSelected = individualTestPanelIds.reduce(
  (acc: boolean, panelId: number) =>
    acc && this.panelIds.indexOf(panelId) > -1,
  individualTestPanelIds.length > 0 &&
  panel.Tests.length === individualTestPanelIds.length
);

// if selected, remove all individual test panels and add the panel group
if (panel.Tests.length > 0 && allIndividualTestsSelected) {
  this.panelIds = this.panelIds.filter(
    panelId => individualTestPanelIds.indexOf(panelId) === -1
  );
  this.selectedPanels = this.selectedPanels.filter(
    selectedPanel => individualTestPanelIds.indexOf(selectedPanel.Id) === -1
  );
  this.panelIds.push(panel.Id);
  this.selectedPanels.push(panel);
  this.updateSession();
 }
  return this.panelIds.indexOf(panel.Id) > -1;
  }


 onPanelCheckboxUpdate($event: boolean, panel: TestOrderPanel) {
   let testPanelIds = panel.Tests.reduce((acc, test) => {
    if (test.AssociatedPanel) {
    acc.push(test.AssociatedPanel.Id);
  }

  return acc;
}, []);
// Wipe any duplicates
this.panelIds = this.panelIds.filter(
  panelId => panel.Id !== panelId && testPanelIds.indexOf(panelId) === -1
);
this.selectedPanels = this.selectedPanels.filter(
  selectedPanel =>
    panel.Id !== selectedPanel.Id &&
    testPanelIds.indexOf(selectedPanel.Id) === -1
);

if ($event) {
  this.panelIds.push(panel.Id);
  this.selectedPanels.push(panel);
   }
   this.updateSession();
 }

 onTestCheckboxUpdate($event: boolean,
                   test: TestOrderPanelTest,
                   panel: TestOrderPanel) {


let testPanelIds = panel.Tests.reduce((acc, test) => {
  if (test.AssociatedPanel) {
    acc.push(test.AssociatedPanel.Id);
  }

  return acc;
}, []);
let associatedTestPanels = this.testSelectionSession.IndividualTestPanelsForAll.filter(
  testPanel => testPanelIds.indexOf(testPanel.Id) > -1
);

let clickedTestPanel = associatedTestPanels.find(
  testPanel => (test.AssociatedPanel ? test.AssociatedPanel.Id : -1) === testPanel.Id
);


if (clickedTestPanel) {
  // Wipe any duplicates
  this.panelIds = this.panelIds.filter(
    panelId => clickedTestPanel.Id !== panelId
  );
  this.selectedPanels = this.selectedPanels.filter(
    panel => clickedTestPanel.Id !== panel.Id
  );

  // Add individual panel if checkbox selected
  if ($event) {
    this.panelIds = this.panelIds.concat(clickedTestPanel.Id);
    console.log(this.panelIds)
    this.selectedPanels = this.selectedPanels.concat(clickedTestPanel);
    console.log(this.selectedPanels)
  }
  }
  this.updateSession();
 }

数组是在this.selectedPanels中如何解决这个问题可以有人帮忙吗？

Answer 1

如果向模板中的ngfor循环添加索引（在下面的代码中为'let i = index'），则可以将其传递给onTestCheckboxUpdate（）函数并在此处拼接源数组：

HTML文件：

<ul>
    <li *ngFor="let item of items; let i = index" [attr.data-index]="I">
        {{item}}
        <button (click)="removeItem(i)">Remove '{{item}}' from array</button>
    </li>
</ul>

TS档案：

items = ['cat','dog','mouse','frog','horse','bird'];

removeItem(itemIndex:number){
    this.items.splice(itemIndex, 1);
}

这会实现您的目标吗？ 这里的基本概念示例。

Answer 2

您可以使用以下方法获取已检查或未选中的项目数。 更新为将'checked'属性添加到数据数组中的每个项目，下面和Stackblitz上 。

TS档案：

items = [
    {name: 'cat'},
    {name: 'dog'},
    {name: 'horse'},
    {name: 'mouse'}
];

checkCount = this.items.length;

checkItem(itemIndex:number){
    if(this.items[itemIndex]['checked'] === undefined){
        this.items[itemIndex]['checked'] = false;
    } else {
        this.items[itemIndex]['checked'] = !this.items[itemIndex]['checked'];
    }
    this.checkCount = this.items.filter(item => item['checked'] === true || item['checked'] === undefined).length;
}

HTML文件：

<ul>
    <li *ngFor="let item of items; let i = index">
        <label>{{item.name}}</label>
        <input type="checkbox" checked (click)="checkItem(i)">
    </li>
</ul>

Check count: {{checkCount}}

这里的例子。

如果需要双向绑定，可以使用formControl来保存每个复选框的“checked”变量，而不是普通的布尔值。 你可以在这里看到一个例子。