Files
brewman/overlord/src/app/employee/employee-list/employee-list-datasource.ts

113 lines
3.4 KiB
TypeScript

import { DataSource } from '@angular/cdk/collections';
import { EventEmitter } from '@angular/core';
import { MatPaginator, PageEvent } from '@angular/material/paginator';
import { MatSort, Sort } from '@angular/material/sort';
import { merge, Observable, of as observableOf } from 'rxjs';
import { map, tap } from 'rxjs/operators';
import { Employee } from '../employee';
/** Simple sort comparator for example ID/Name columns (for client-side sorting). */
const compare = (a: string | number, b: string | number, isAsc: boolean) =>
(a < b ? -1 : 1) * (isAsc ? 1 : -1);
export class EmployeeListDataSource extends DataSource<Employee> {
private filterValue = '';
constructor(
public data: Employee[],
private filter: Observable<string>,
private paginator?: MatPaginator,
private sort?: MatSort,
) {
super();
this.filter = filter.pipe(
tap((x) => {
this.filterValue = x;
}),
);
}
connect(): Observable<Employee[]> {
const dataMutations: (
| Observable<Employee[]>
| Observable<string>
| EventEmitter<PageEvent>
| EventEmitter<Sort>
)[] = [observableOf(this.data), this.filter];
if (this.paginator) {
dataMutations.push((this.paginator as MatPaginator).page);
}
if (this.sort) {
dataMutations.push((this.sort as MatSort).sortChange);
}
return merge(...dataMutations)
.pipe(
map(() => this.getFilteredData([...this.data])),
tap((x: Employee[]) => {
if (this.paginator) {
this.paginator.length = x.length;
}
}),
)
.pipe(map((x: Employee[]) => this.getPagedData(this.getSortedData(x))));
}
disconnect() {}
private getFilteredData(data: Employee[]): Employee[] {
return this.filterValue.split(' ').reduce(
(p: Employee[], c: string) =>
p.filter((x) => {
const employeeString = `${x.code} ${x.name} ${x.designation} ${x.costCentre}${
x.isActive ? ' active' : ' inactive'
}`.toLowerCase();
return employeeString.indexOf(c) !== -1;
}),
Object.assign([], data),
);
}
private getPagedData(data: Employee[]) {
if (this.paginator === undefined) {
return data;
}
const startIndex = this.paginator.pageIndex * this.paginator.pageSize;
return data.splice(startIndex, this.paginator.pageSize);
}
private getSortedData(data: Employee[]) {
if (this.sort === undefined) {
return data;
}
if (!this.sort.active || this.sort.direction === '') {
return data;
}
const sort = this.sort as MatSort;
return data.sort((a, b) => {
const isAsc = sort.direction === 'asc';
switch (sort.active) {
case 'code':
return compare(+a.code, +b.code, isAsc);
case 'name':
return compare(a.name, b.name, isAsc);
case 'designation':
return compare(a.designation, b.designation, isAsc);
case 'salary':
return compare(a.salary, b.salary, isAsc);
case 'points':
return compare(a.points, b.points, isAsc);
case 'department':
return compare(a.costCentre.name, b.costCentre.name, isAsc);
case 'joiningDate':
return compare(a.joiningDate, b.joiningDate, isAsc);
case 'leavingDate':
return compare(a.leavingDate || '', b.leavingDate || '', isAsc);
default:
return 0;
}
});
}
}