Could not get plugins work with wavesurfer.js using typescript

Question

I am trying to generate a wave form for the audio and video content in my application, currently using angular 6 and TypeScript. I could make the wave form using the wavesurfer.js but i could not get the timeline plug in working. In my angular.json i have scripts like this

"scripts": [
          "node_modules/jquery/dist/jquery.min.js",  
          "node_modules/popper.js/dist/umd/popper.min.js",  
          "node_modules/bootstrap/dist/js/bootstrap.min.js",
          "node_modules/moment/min/moment.min.js",
          "node_modules/wavesurfer.js/dist/wavesurfer.js",
          "node_modules/wavesurfer.js/dist/plugin/wavesurfer.timeline.js" 
        ]

and in my component.ts file i have code like

declare var WaveSurfer;
declare var TimelinePlugin;

export class TranscriptComponent implements OnInit {

 ngAfterViewInit() {
  this.wavesurfer = WaveSurfer.create({
   container: '#waveform',
   waveColor: 'violet',
   progressColor: 'purple',
   cursorColor: '#d9fb36',
   normalize: true,
   skipLength: 15,
   hideScrollbar: true,
   backend: 'MediaElement',
   plugins: [
     TimelinePlugin.create({
       // plugin options ...
     })
   ]
 });

}

with-out the plugin i could get the waveform, but if i try to add the plugins, i get error "TimelinePlugin is undefined." Can any tell me how to use these plugins using typescript. An Example would be great.

Answer 1

I got this working (after some trial-and-error) by explicitly adding the path to the plugin I needed to the 'scripts' arrays (architect and test) in angular.json:

"scripts": [
    "./node_modules/wavesurfer.js/dist/wavesurfer.js",
    "./node_modules/wavesurfer.js/dist/plugin/wavesurfer.regions.js"
],

I then imported the plugin into the component with the audio player:

import * as WaveSurfer from 'wavesurfer.js';
import * as WaveSurferRegions from 'wavesurfer.js/dist/plugin/wavesurfer.regions.js';

And initialised the player:

ws: any;

ngOnInit() {
    this.ws = WaveSurfer.create({
        container: document.querySelector('#player_waveform'),
        backend: 'MediaElement',
        plugins: [
            WaveSurferRegions.create({
                regions: [
                    {
                        start: 1,
                        end: 3,
                        color: 'hsla(400, 100%, 30%, 0.5)'
                    }, {
                        start: 5,
                        end: 7,
                        color: 'hsla(200, 50%, 70%, 0.4)'
                    }
                ]
            })
        ]
    });
}

I also made some changes to npm but hard to say whether this is what got things working. I did have both the newer wavesurfer.js and wavesurfer installed. I removed wavesurfer, which might have helped?