Filtering specific column in Angular Material table in angular 5 [duplicate]

Working filters on each column, demo link Stackblitz.

To filter specific column in mat-table, add a search field for the column as below;

<mat-form-field class="filter" floatLabel="never">
    <mat-label>Search</mat-label>
    <input matInput [formControl]="nameFilter">
  </mat-form-field>

And we connect the inputs to FormControls from the ReactiveFormsModule.

    filterValues = {
    name: '',
    id: '',
    colour: '',
    pet: ''
 };

And we will watch the value of the filter inputs and modify this filter object and the data source’s filter property when they change. We must assign the stringified version of the filter object to the data source’s filter property

    ngOnInit() {
    this.nameFilter.valueChanges
      .subscribe(
        name => {
          this.filterValues.name = name;
          this.dataSource.filter = JSON.stringify(this.filterValues);
        }
      )
    this.idFilter.valueChanges
      .subscribe(
        id => {
          this.filterValues.id = id;
          this.dataSource.filter = JSON.stringify(this.filterValues);
        }
      )
    this.colourFilter.valueChanges
      .subscribe(
        colour => {
          this.filterValues.colour = colour;
          this.dataSource.filter = JSON.stringify(this.filterValues);
        }
      )
    this.petFilter.valueChanges
      .subscribe(
        pet => {
          this.filterValues.pet = pet;
          this.dataSource.filter = JSON.stringify(this.filterValues);
        }
      )
  }

We have to change the data source’s filterPredicate to tell it how to interpret the filter information.

    constructor() {
    this.dataSource.data = this.people;
    this.dataSource.filterPredicate = this.tableFilter();
    }

    tableFilter(): (data: any, filter: string) => boolean {
    let filterFunction = function(data, filter): boolean {
      let searchTerms = JSON.parse(filter);
      return data.name.toLowerCase().indexOf(searchTerms.name) !== -1
        && data.id.toString().toLowerCase().indexOf(searchTerms.id) !== -1
        && data.colour.toLowerCase().indexOf(searchTerms.colour) !== -1
        && data.pet.toLowerCase().indexOf(searchTerms.pet) !== -1;
    }
    return filterFunction;
}