find and update methods not working.

this.userUpdated= this.source.find(p); is not working.

i need your help now. please send me a sloution. I want to update my row after i edit from database

this.source.update(this.userUpdated, this.model);

it throws this exception:
EXCEPTION: Uncaught (in promise): Error: Element was not found in the dataset
Error: Element was not found in the dataset

my codes:

import { Component, OnInit, ViewChild, ViewEncapsulation } from '@angular/core';
import {User} from '../../model/user';
import {UserService} from '../../shared/user/user.service';
import { Ng2SmartTableModule, LocalDataSource } from 'ng2-smart-table';
import { ModalComponent } from 'ng2-bs3-modal/ng2-bs3-modal';

@Component({
selector: 'app-adduser',
templateUrl: './adduser.component.html',
styleUrls: ['./adduser.component.css']
})
export class AdduserComponent implements OnInit {
@ViewChild('validationModal')
modal: ModalComponent;
user: User;
model: User = new User();
userUpdated: User= new User();
selected: string;
output: string;
userId: number;
actionType: number;
index: number = 0;
backdropOptions = [true, false, 'static'];
cssClass: string = '';

animation: boolean = true;
keyboard: boolean = true;
backdrop: string | boolean = true;
css: boolean = false;

close() {
this.modal.close();
}

closed() {
this.output = '(closed) ' + this.selected;
console.log("hps:" + this.output);
}

errorMessage = "user listeleme sayfası";
userList: User[] = [];

settings = {

edit: {
confirmEdit: true
},

delete: {
confirmDelete: true
},
columns: {
id: {
title: 'ID'
},
name: {
title: 'Full Name'
},
surname: {
title: 'Surname'
},
username: {
title: 'User Name'
},
email: {
title: 'Email'
}
}
};
source: LocalDataSource;
constructor(private userService: UserService) {
this.source = new LocalDataSource(this.userList); // create the source
this.actionType = 0;

}

//p => this.userList = p
ngOnInit() {
console.log("user componant içi");
this.userService
.listUsers()
.subscribe(p => this.source.load(p))
}
newPost() {
this.actionType = 1;//it means create
this.modal.open();

}


onSelectRow(event): void {

this.userId = event.data.id;
this.userService
.findUserById(this.userId)
.subscribe(p => {
this.model = p;
this.userUpdated= this.source.find(p);
console.log(this.userUpdated.id+" "+this.userUpdated.name);
console.log(p.id+" "+p.name);
});

this.actionType = 2;//it means update
this.modal.open();

}

onDeleteConfirm(event): void {
if (window.confirm('Are you sure you want to delete?')) {
event.confirm.resolve();
} else {
event.confirm.reject();
}
}

saveUser() {
console.log("user saveUser içi");
if (this.actionType == 1) {
this.userService.addUser(this.model)
.subscribe(res => {
console.log(JSON.stringify(res.data._body));
this.model.id = res.data._body;
this.source.prepend(this.model);
},
err => { console.log(err) });
} else if (this.actionType == 2) {
this.userService.updateUser(this.model)
.subscribe(res => {
console.log(this.model.id + '-' + this.model.name);

this.source.update(this.userUpdated, this.model);

this.userUpdated= {};
},
err => { console.log(err) });
}
this.model = {};
this.modal.close();

console.log("user saveUser dışı" + this.actionType);
this.actionType = 0;
}

}