Angular 数据 table 中缺少字段时出错

Question

我正在试验 Angular Cli 6 来评估项目的框架。我坚持使用 Material 数据 Table 示例 https://material.angular.io/components/table/overview

如果我的数据 json (PeriodicElement) 缺少一个字段，我不知道如何处理这种情况。例如，如果字段

symbol: 'H'

在第一个 json 对象中丢失。 Angular 给我

error:  Property 'symbol' is missing in symbol

table 应该出现，当缺少字段时，它应该是空的，如空字符串或 table 中的 null。



    import {Component} from '@angular/core';

    export interface PeriodicElement {
        name: string;
        position: number;
        weight: number;
        symbol: string;
    }

    const ELEMENT_DATA: PeriodicElement[] = [
        {position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H'},
        {position: 2, name: 'Helium', weight: 4.0026, symbol: 'He'},
        {position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li'},
        {position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be'},
        {position: 5, name: 'Boron', weight: 10.811, symbol: 'B'},
        {position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C'},
        {position: 7, name: 'Nitrogen', weight: 14.0067, symbol: 'N'},
        {position: 8, name: 'Oxygen', weight: 15.9994, symbol: 'O'},
        {position: 9, name: 'Fluorine', weight: 18.9984, symbol: 'F'},
        {position: 10, name: 'Neon', weight: 20.1797, symbol: 'Ne'},
    ];

    /**
     * @title Basic use of ``
     */
    @Component({
       selector: 'table-basic-example',
       styleUrls: ['table-basic-example.css'],
       templateUrl: 'table-basic-example.html',
    })
    export class TableBasicExample {
       displayedColumns: string[] = ['position', 'name', 'weight', 'symbol'];
        dataSource = ELEMENT_DATA;
    }

Answer 1

在你的情况下，使用像这样的带有可选参数的接口可能更方便

export interface PeriodicElement {
        name: string;
        position: number;
        weight: number;
        symbol?: string;
}

Angular 数据 table 中缺少字段时出错

Error when a field is missing in Angular data table

angular-datatables

angular

angular-material-6