【发布时间】：2018-05-06 17:11:16
【问题描述】：
经过几周的谷歌搜索和到目前为止只有一个 Stackoverflown 问题，我终于设法使用 Material Table Component 构建了我的 Angular CRUD 应用程序。它显示来自后端 (JSON) 的数据，对于 CRUD 操作，我正在使用如图所示的对话框（这是编辑，抱歉克罗地亚语）。对话框可能不是最好的方法，内联编辑可能会更好。但是，要添加新项目，您需要对话框之类的东西。
我坚持的最后一件事是如何相应地更新表中的字段。因此，当您在对话框中按“保存”时，数据会在后端（在 MySQL 表中）更新，但不会在前端更新。目前我有一个丑陋的解决方法，每次你进行更新时，它也会刷新整个表。
代码如下：
表格组件：
export class BazaComponent implements OnInit {
....
constructor(public httpClient: HttpClient, public dialog: MatDialog) {
}
ngOnInit() {
this.loadData();
}
// TODO: Simplfy this...
addNew(ident: number, naziv: string, mt: number, kutija: number,
komada: number, jm: string, orginal: number, lokacija: number, napomena: string) {
console.log('add new clicked');
const dialogRef = this.dialog.open(AddDialogComponent, {
data: {ident: ident, naziv: naziv, mt: mt, kutija: kutija,
komada: komada, jm: jm, orginal: orginal, lokacija: lokacija, napomena: napomena }
});
dialogRef.afterClosed().subscribe(result => {
console.log(result);
if (result === 1) {
this.loadData(); // --> This is a temp workaround, every time when I do CRUD operation just redraw whole thing again
}
});
}
startEdit(id: number, ident: number, naziv: string, mt: number, kutija: number,
komada: number, jm: string, orginal: number, lokacija: number, napomena: string) {
const dialogRef = this.dialog.open(EditDialogComponent, {
data: {id: id, ident: ident, naziv: naziv, mt: mt, kutija: kutija,
komada: komada, jm: jm, orginal: orginal, lokacija: lokacija, napomena: napomena}
});
dialogRef.afterClosed().subscribe(result => {
if (result === 1) {
this.loadData(); // --> This is a temp workaround, every time when I do CRUD operation just redraw whole thing again
}
});
}
deleteItem(id: number, ident: number, naziv: string, mt: number) {
const dialogRef = this.dialog.open(DeleteDialogComponent, {
data: {id: id, ident: ident, naziv: naziv, mt: mt}
});
dialogRef.afterClosed().subscribe(result => {
if (result === 1) {
this.loadData();
}
});
}
public loadData() {
this.exampleDatabase = new DataService(this.httpClient);
this.dataSource = new ExampleDataSource(this.exampleDatabase, this.paginator, this.sort);
Observable.fromEvent(this.filter.nativeElement, 'keyup')
.debounceTime(150)
.distinctUntilChanged()
.subscribe(() => {
if (!this.dataSource) {
return;
}
this.dataSource.filter = this.filter.nativeElement.value;
});
}
}
export class ExampleDataSource extends DataSource<Baza> {
_filterChange = new BehaviorSubject('');
get filter(): string {
return this._filterChange.value;
}
set filter(filter: string) {
this._filterChange.next(filter);
}
filteredData: Baza[] = [];
renderedData: Baza[] = [];
constructor(private _exampleDatabase: DataService,
private _paginator: MatPaginator,
private _sort: MatSort) {
super();
// Reset to the first page when the user changes the filter.
this._filterChange.subscribe(() => this._paginator.pageIndex = 0);
}
/** Connect function called by the table to retrieve one stream containing the data to render. */
connect(): Observable<Baza[]> {
// Listen for any changes in the base data, sorting, filtering, or pagination
const displayDataChanges = [
this._exampleDatabase.dataChange,
this._sort.sortChange,
this._filterChange,
this._paginator.page,
];
this._exampleDatabase.getAllItems();
return Observable.merge(...displayDataChanges).map(() => {
// Filter data
this.filteredData = this._exampleDatabase.data.slice().filter((item: Baza) => {
const searchStr = (item.ident + item.naziv + item.mt + item.lokacija + item.napomena).toLowerCase();
return searchStr.indexOf(this.filter.toLowerCase()) !== -1;
});
// Sort filtered data
const sortedData = this.sortData(this.filteredData.slice());
// Grab the page's slice of the filtered sorted data.
const startIndex = this._paginator.pageIndex * this._paginator.pageSize;
this.renderedData = sortedData.splice(startIndex, this._paginator.pageSize);
return this.renderedData;
});
}
disconnect() {
}
/** Returns a sorted copy of the database data. */
sortData(data: Baza[]): Baza[] {
... sort stuff
}
这是我想我应该进行字段更新的 DataService：
import { Injectable } from '@angular/core';
import { HttpClient, HttpErrorResponse, HttpHeaders} from '@angular/common/http';
import { Baza } from '../models/kanban.baza';
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
@Injectable()
export class DataService {
private readonly API_URL = 'http://localhost/api/'
/** Stream that emits whenever the data has been modified. */
dataChange: BehaviorSubject<Baza[]> = new BehaviorSubject<Baza[]>([]);
constructor(private httpClient: HttpClient) {
}
get data(): Baza[] {
return this.dataChange.value;
}
getAllItems(): void {
this.httpClient.get<Baza[]>(this.API_URL).subscribe(data => {
this.dataChange.next(data['items']);
});
}
addItem(baza: Baza): void {
this.httpClient.post(this.API_URL, Baza).subscribe(data => {
//THIS WAS MY BEST TRY BUT IT DOESN'T WORK :(
const copiedData = this.data.slice();
copiedData.push(baza);
console.log(copiedData);
this.dataChange.next(copiedData);
});
}
updateItem(baza: Baza): void {
this.httpClient.put(this.API_URL + baza.id, baza).subscribe();
}
deleteItem(id: number): void {
this.httpClient.delete(this.API_URL + id, {headers: new HttpHeaders().set('Access-Control-Allow-Origin', '*')} ).subscribe();
}
}
2017 年 11 月 27 日更新：
好的，我终于想出了如何触发新行添加。我不得不在表格组件内调用dataChange.value。一旦你用一些数据加载它，新行就会立即出现。
const data = {id: 208, ident: 233, naziv: 'test', mt: 291, komada: 2, jm: 'a', orginal: 100, lokacija: 3, napomena: 'pls work'};
this.exampleDatabase.dataChange.value.push(data);
DataService 中同样的事情不起作用：
this.dataChange.value.push(data);
Plunker 来了：
https://plnkr.co/edit/IWCVsBRl54F7ylGNIJJ3?p=info
编辑 28.11.2017：
现在只剩下构建添加、编辑和删除的逻辑了。因为添加很简单，它只是`value.push(data)'。谢谢大家的帮助。
【问题讨论】：
标签： angular crud angular-material2