如何在角度组件模板中使用Spread Operator [英] How to use Spread Operator in angular component template

问题描述

我想从组件模板将数组传递给函数.
这是我的工具栏:
toolbar.component.html

<div *ngFor="let item of items">
   <button mat-mini-fab [style.color]="item.color" 
    (click)="item.command(...item.commandParams)">
     <i class="material-icons">{{item.icon}}</mat-icon>
   </button>
 </div>

toolbar.component.ts

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

@Component({
  selector: 'app-toolbar',
  templateUrl: './toolbar.component.html',
  styleUrls: ['./toolbar.component.scss']
})
export class ToolbarComponent implements OnInit {
  items: ToolBarItem[]

  constructor() {
  }

  ngOnInit() {
  }
}

export class ToolBarItem {
  icon = 'border_clear';
  color: string;
  command: () => void;
  commandParams: any[];
}

在这里，我想使用各种命令来初始化工具栏的项目.
main.ts

...
items: [
        {
          icon: 'mode_edit',
          color: 'blue',
          command: (name, family) => {
            console.log('editClick!' + name + family);
          },
          commandParams: ['mohammad', 'farahmand'],
        },
        {
          icon: 'delete',
          color: 'red',
          command: () => {
            console.log('deleteClick!');
          },
        }
      ],
...

但是我得到这个错误:

错误:模板解析错误:解析器错误:意外令牌.在 ...

中的[item.command(... item.commandParams)]中的第14列

解决方案

不太可能使这种语法在模板中工作(有很多有效的打字稿结构在模板中不起作用)./p>

您可以改为在组件中编写一个辅助方法，该方法将该项作为参数，然后进行适当的调用，例如:

public doCommand(item: ToolbarItem): void {
  item.command(...item.commandParams);
}

，然后将模板更改为:

(click)="doCommand(item)"

I want to pass an array to a function from component template.
This is my toolbar:
toolbar.component.html

<div *ngFor="let item of items">
   <button mat-mini-fab [style.color]="item.color" 
    (click)="item.command(...item.commandParams)">
     <i class="material-icons">{{item.icon}}</mat-icon>
   </button>
 </div>

toolbar.component.ts

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

@Component({
  selector: 'app-toolbar',
  templateUrl: './toolbar.component.html',
  styleUrls: ['./toolbar.component.scss']
})
export class ToolbarComponent implements OnInit {
  items: ToolBarItem[]

  constructor() {
  }

  ngOnInit() {
  }
}

export class ToolBarItem {
  icon = 'border_clear';
  color: string;
  command: () => void;
  commandParams: any[];
}

Here I want to init items of toolbar with varies commands.
main.ts

...
items: [
        {
          icon: 'mode_edit',
          color: 'blue',
          command: (name, family) => {
            console.log('editClick!' + name + family);
          },
          commandParams: ['mohammad', 'farahmand'],
        },
        {
          icon: 'delete',
          color: 'red',
          command: () => {
            console.log('deleteClick!');
          },
        }
      ],
...

But i get this error:

Error: Template parse errors: Parser Error: Unexpected token . at column 14 in [item.command(...item.commandParams)] in ...

解决方案

It's unlikely that you're going to get this syntax to work in a template (there are many valid typescript constructs that don't work in templates).

You could write a helper method in the component instead, that takes the item as an argument, and then makes the appropriate call, as in, for example:

public doCommand(item: ToolbarItem): void {
  item.command(...item.commandParams);
}

and then change your template to:

(click)="doCommand(item)"

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