我想设置默认关键字值null，并且还想设置错误消息，如果关键字找不到记录，则如何可能

Question

HTML 组件：

<form class="navbar-form navbar-right">
  <input type="text" class="form-control" 
        name="keyword" [(ngModel)]="model.keyword" placeholder="Search...">
  <button class="btn btn-primary" (click)="getEmployees()">Search</button>
</form>

元件： 我想将null设置为keyword的默认值

getEmployees(page:number,keyword:string): void {
  this.employeeService.getEmployees(page,this.model.keyword)
    .subscribe(employees => { 
      this.employees = employees;
      console.log(this.employees);
      this.setPage(page);
      console.log(this.model.keyword)
    });
}

Answer 1

 getEmployees(page:number,keyword:string): void {
        // get users from secure api end point
        var query = (this.model.keyword) ? this.model.keyword : "";
        this.employeeService.getEmployees(page,query)
            .subscribe(employees => {
                this.employees = employees;
                console.log(this.employees);
                this.setPage(page);           
            });
    }