具有列值的材料表数据源过滤器

Question

如何使用特定列过滤材料数据表？

public dataSource;


this.dataSource = new MatTableDataSource(this.items);
        this.dataSource.filterPredicate = function customFilter(data , filter:string ): boolean {
            return (data.name.startsWith(filter));
        }

applyFilter(filterValue: string) {
    filterValue = filterValue.trim(); // Remove whitespace
    filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
    this.dataSource.filter = filterValue;
}

---

当我键入返回时,上面的代码不起作用,因为没有数据匹配.

Answer 1

来自文档.

例如,数据对象{id:123,name:'Mr. Smith',favoriteColor:'blue'}将减少到123mr.smithblue.如果您的过滤字符串是蓝色,那么它将被视为匹配,因为它包含在缩减字符串中,并且该行将显示在表中.

要覆盖默认筛选行为,可以设置自定义filterPredicate函数,该函数接受数据对象和过滤器字符串,如果数据对象被视为匹配,则返回true.

如果您只想使用过滤器特定列,则需要覆盖filterPredicate,答案已在此处.

这是过滤的工作示例.

表滤波-example.html的

<div class="example-container mat-elevation-z8">
  <div class="example-header">
    <mat-form-field>
      <input matInput (keyup)="applyFilter($event.target.value)" placeholder="Filter">
    </mat-form-field>
  </div>

  <mat-table #table [dataSource]="dataSource">

    <!-- Position Column -->
    <ng-container matColumnDef="position">
      <mat-header-cell *matHeaderCellDef> No. </mat-header-cell>
      <mat-cell *matCellDef="let element"> {{element.position}} </mat-cell>
    </ng-container>

    <!-- Name Column -->
    <ng-container matColumnDef="name">
      <mat-header-cell *matHeaderCellDef> Name </mat-header-cell>
      <mat-cell *matCellDef="let element"> {{element.name}} </mat-cell>
    </ng-container>

    <!-- Weight Column -->
    <ng-container matColumnDef="weight">
      <mat-header-cell *matHeaderCellDef> Weight </mat-header-cell>
      <mat-cell *matCellDef="let element"> {{element.weight}} </mat-cell>
    </ng-container>

    <!-- Symbol Column -->
    <ng-container matColumnDef="symbol">
      <mat-header-cell *matHeaderCellDef> Symbol </mat-header-cell>
      <mat-cell *matCellDef="let element"> {{element.symbol}} </mat-cell>
    </ng-container>

    <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
    <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
  </mat-table>
</div>

表滤波-example.ts

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

    /**
     * @title Table with filtering
     */
    @Component({
      selector: 'table-filtering-example',
      styleUrls: ['table-filtering-example.css'],
      templateUrl: 'table-filtering-example.html',
    })
    export class TableFilteringExample {
      displayedColumns = ['position', 'name', 'weight', 'symbol'];
      dataSource = new MatTableDataSource(ELEMENT_DATA);

      applyFilter(filterValue: string) {
        filterValue = filterValue.trim(); // Remove whitespace
        filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
        this.dataSource.filter = filterValue;
      }
    }

    export interface Element {
      name: string;
      position: number;
      weight: number;
      symbol: string;
    }

    const ELEMENT_DATA: Element[] = [
      {position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H'},
      {position: 2, name: 'Helium', weight: 4.0026, symbol: 'He'},
      {position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li'},
      {position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be'},
      {position: 5, name: 'Boron', weight: 10.811, symbol: 'B'},
      {position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C'},
      {position: 7, name: 'Nitrogen', weight: 14.0067, symbol: 'N'},
      {position: 8, name: 'Oxygen', weight: 15.9994, symbol: 'O'},
      {position: 9, name: 'Fluorine', weight: 18.9984, symbol: 'F'},
      {position: 10, name: 'Neon', weight: 20.1797, symbol: 'Ne'},
      {position: 11, name: 'Sodium', weight: 22.9897, symbol: 'Na'},
      {position: 12, name: 'Magnesium', weight: 24.305, symbol: 'Mg'},
      {position: 13, name: 'Aluminum', weight: 26.9815, symbol: 'Al'},
      {position: 14, name: 'Silicon', weight: 28.0855, symbol: 'Si'},
      {position: 15, name: 'Phosphorus', weight: 30.9738, symbol: 'P'},
      {position: 16, name: 'Sulfur', weight: 32.065, symbol: 'S'},
      {position: 17, name: 'Chlorine', weight: 35.453, symbol: 'Cl'},
      {position: 18, name: 'Argon', weight: 39.948, symbol: 'Ar'},
      {position: 19, name: 'Potassium', weight: 39.0983, symbol: 'K'},
      {position: 20, name: 'Calcium', weight: 40.078, symbol: 'Ca'}, ];

你可以使用filterPredicate来过滤特定的列,如下所示:

  ngOnInit() {
    this.dataSource.filterPredicate = (data: Element, filter: string) => {
      return data.name == filter;
     };
   }
 applyFilter(filterValue: string) {
    // filterValue = filterValue.trim(); // Remove whitespace
    // filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
    this.dataSource.filter = filterValue;
  }

我改变了applyFilter()并添加了ngOnInit().现在它只使用名称列和完全相同的值(==)

Answer 2

您可以利用mat-table-filter进行复杂的过滤。

为了过滤列，您定义一个示例实体并仅填充属于相应列的属性。

这是一个例子：https : //stackblitz.com/github/HalitTalha/mat-table-filter-example

Answer 3

您可以通过动态列进行过滤，就像在没有硬编码的列名中一样，执行以下操作：

// On input focus: setup filterPredicate to only filter by input column
setupFilter(column: string) {
  this.dataSource.filterPredicate = (d: TableDataSourceType, filter: string) => {
    const textToSearch = d[column] && d[column].toLowerCase() || '';
    return textToSearch.indexOf(filter) !== -1;
  };
}

applyFilter(filterValue: string) {
  this.dataSource.filter = filterValue.trim().toLowerCase();
}

在模板中，你可以有这样的东西：

<ng-container matColumnDef="item-filter">
  <th mat-header-cell *matHeaderCellDef>
    <input (keyup)="applyFilter($event.target.value)" (focus)="setupFilter('name')" />
  </th>
</ng-container>

或者一个更复杂的例子，动态创建一个带有每列过滤的标题行：

<table mat-table [dataSource]="dataSource">
   <ng-container *ngFor="let filterCol of ['names', 'age', 'address']">
     <ng-container matColumnDef="filterCol">
       <th mat-header-cell *matHeaderCellDef>
         <input (keyup)="applyFilter($event.target.value)" (focus)="setupFilter(filterCol)"/>
       </th>
     </ng-container>
   </ng-container>

   <tr mat-header-row *matHeaderRowDef="['names', 'age', 'address']"></tr>
</table>

请注意，您不能有多个具有相同键的标题行，因此这将不起作用：

<tr mat-header-row *matHeaderRowDef="['names', 'age', 'address']"></tr>
<tr mat-header-row *matHeaderRowDef="['names', 'age', 'address']"></tr>

Answer 4

使用filterPredicate为Material 表创建自定义过滤器选择框以覆盖customFilter()方法

演示链接

源链接

        ...
        ngOnInit() {
            this.getRemoteData();

            // Overrride default filter behaviour of Material Datatable
            this.dataSource.filterPredicate = this.createFilter();
        }
        ...

        // Custom filter method fot Angular Material Datatable
        createFilter() {
            let filterFunction = function (data: any, filter: string): boolean {
            let searchTerms = JSON.parse(filter);
            let isFilterSet = false;
            for (const col in searchTerms) {
                if (searchTerms[col].toString() !== '') {
                isFilterSet = true;
                } else {
                delete searchTerms[col];
                }
            }

            let nameSearch = () => {
                let found = false;
                if (isFilterSet) {
                for (const col in searchTerms) {
                    searchTerms[col].trim().toLowerCase().split(' ').forEach(word => {
                    if (data[col].toString().toLowerCase().indexOf(word) != -1 && isFilterSet) {
                        found = true
                    }
                    });
                }
                return found
                } else {
                return true;
                }
            }
            return nameSearch()
            }
            return filterFunction
        }