Download a file in JavaScript/TypeScript (click handler for a button)

download-file.ts

import * as stringify from 'json-stringify-safe';

const format = 'json';
const outputData = stringify(this.model);

const mimeTypes = {
  'json': 'application/json',
  'csv': 'text/csv',
  'xml': 'text/xml',
  'txt': 'text/plain'
};
const blob = new Blob([outputData], { type: `${mimeTypes[format]};charset=utf-8;` });
const link = document.createElement('a');
if (link.download !== undefined) { // feature detection
  // Browsers that support HTML5 download attribute
  const url = URL.createObjectURL(blob);
  link.setAttribute('href', url);
  link.setAttribute('download', `${this.fileName}.${format}`);
  link.style.visibility = 'hidden';
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
}