How to make excerpt filter in angular 2?

Question

i'm new to angular 2 , i used to get the excerpt of a text in angularjs with a filter like this :

app.filters.js:

app.filter('excerpt', function () {
    return function (text, length) {
        if (text.length > length) {
            return text.substr(0, length) + '...';
        }
        return text;
    }
}); 

in html file :

{{blog.content | excerpt:90}}

what's the equivalent in angular 2 ?

Answer 1

This should be doing it :

• First create your filter .ts file :

excerpt.filter.ts

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'excerpt',
  pure: false
})
export class ExcerptFilter implements PipeTransform {
  transform(text: String, length:any ): any {
    if (!text || !length) {
      return text;
    }
    if (text.length > length) {
      return text.substr(0, length) + '...';
    }
      return text;

  }
}

• Then you can use it like the following :

template.component.html

<div class="description">{{blog.content | excerpt:90}} </div>

• Make sure that you're importing your filter in app.module.ts file :

  import {ExcerptFilter} from './filters/excerpt.filter';

for more infos about creating pipes see the Docs