在 Angular 6 中将多个值传递给管道

Question

我需要在 Angular 6 中使用 pipe 创建一个搜索表单，并且必须将多个参数传递给 pipe 。

nameSearch、emailSearch、roleSeach、accountSearch

 <tr *ngFor="let user of data | searchuser: nameSearch" ></tr>

这是我的烟斗：

@Pipe({
  name: 'searchuser'
})
export class SearchuserPipe implements PipeTransform {

  transform(users: IUser[], nameSearch: string): IUser[] {
    if(!users) return [];
    if(!nameSearch) return users;

    nameSearch=nameSearch.toLocaleLowerCase();
    return users.filter(item=>
      {
         return item.desplayName.toLocaleLowerCase().includes(nameSearch)
      });
  }

请指导我如何使用多参数创建管道搜索。

编辑：

  transform(users: IUser[], nameSearch: string ,eamilSearch:string,roleSearch:string): IUser[] {
if(!users) return [];
if(!nameSearch) return users;
if(!eamilSearch) return users;
if(!roleSearch) return users;

nameSearch=nameSearch.toLocaleLowerCase();
return users.filter(item=>
  {
      item.desplayName.toLocaleLowerCase().includes(nameSearch),
      item.email.toLocaleLowerCase().includes(eamilSearch),
      item.description.toLocaleLowerCase().includes(roleSearch)          
  });
}

Answer 1

它应该与你传递单个参数的方式相同，如下所示，

export class SearchuserPipe implements PipeTransform {  
   transform(users: IUser[], nameSearch:string, emailSearch:string, roleSearch:
   string):IUser[] {
}

在模板中，

<tr *ngFor="let user of data | searchuser: nameSearch : emailSearch : roleSearch" ></tr>

Answer 2

您可以向必须在管道中实现的 transform 方法添加更多参数。

将这些参数设置为可选参数，以便您可以根据需要使用它们。

像这样：

import { Pipe, PipeTransform } from '@angular/core';

export interface IUser {
  displayName: string;
  name: string;
  email: string;
  role: string;
  account: string;
  description: string;
}

@Pipe({
  name: 'searchUser'
})
export class SearchUserPipe implements PipeTransform {

  transform(
    users: IUser[],
    nameSearch?: string,
    emailSearch?: string,
    roleSearch?: string,
    accountSearch?: string
  ): IUser[] {

    if (!users) return [];
    if (!nameSearch) return users;
    nameSearch = nameSearch.toLocaleLowerCase();
    users = [...users.filter(user => user.displayName.toLocaleLowerCase() ===  nameSearch)];

    if (!emailSearch) return users;
    emailSearch = emailSearch.toLocaleLowerCase();
    users = [...users.filter(user => user.email.toLocaleLowerCase() ===  emailSearch)];

    if (!roleSearch) return users;
    roleSearch = roleSearch.toLocaleLowerCase();
    users = [...users.filter(user => user.role.toLocaleLowerCase() ===  roleSearch)];

    return users;
  }
}

现在在您的模板中，您可以简单地使用此 pipe 并传递由颜色分隔的参数 (:)，如下所示：

<input type="text" placeholder="name" [(ngModel)]="nameSearch">
<input type="text" placeholder="email" [(ngModel)]="emailSearch">
<input type="text" placeholder="role" [(ngModel)]="roleSearch">
<input type="text" placeholder="account" [(ngModel)]="accountSearch">

<table>
  <tbody>
    <tr *ngFor="let user of data | searchUser: nameSearch: emailSearch: roleSearch: accountSearch">
      <td>
        {{ user | json }}
      </td>
    </tr>
  </tbody>
</table>

这里还有组件代码：

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

@Component({...})
export class AppComponent  {

  nameSearch = '';
  emailSearch = '';
  roleSearch = '';
  accountSearch = '';

  data = [...];
}

这里有一个 Working Sample StackBlitz 供您参考。

在 Angular 6 中将多个值传递给管道

Pass multiple values to pipe in Angular 6

angular-pipe

angular

angular6