Angular 4.3: Getting an arraybuffer with new HttpClient

So Martin has solved my issue:

getXlsx (): Observable<any> {    return this.http.get('api/xlsx', {      responseType: 'blob' // <-- changed to blob    })    .map(res => downloadFile(res, 'application/xlsx', 'export.xlsx'))    .catch(err => handleError(err));  }export function downloadFile(blob: any, type: string, filename: string): string {  const url = window.URL.createObjectURL(blob); // <-- work with blob directly  // create hidden dom element (so it works in all browsers)  const a = document.createElement('a');  a.setAttribute('style', 'display:none;');  document.body.appendChild(a);  // create file, attach to hidden element and open hidden element  a.href = url;  a.download = filename;  a.click();  return url;}

The above works and is an acceptable solution, however seems like a code smell just adding anchor tags to the DOM and faking a click when you can do it in a much cleaner way. We've recently had a similar issue for downloading documents in general from an Angular 5 website in which we have used FileSaver(https://www.npmjs.com/package/file-saver) .

Adding FileSaver using npm install file-saver and doing the relevant imports you can use the following code to download a file:

getDocument(document: Document) {    let headers = new HttpHeaders(); // additional headers in here    return this._http.get(url, {        headers: headers,        responseType: "blob" // this line being the important part from the previous answer (thanks for that BTW Martin)     }).map(        res => {            var x = res;            if (res) {                let filename = documentName;                saveAs(x, filename);            }            return true;        },        err => {            return true;        }    );} 

This uses the native saveAs command if it exists and implements some other logic to replicate the functionality if it doesn't.

This may do a similar thing under the hood (i don't really know as haven't had the change to look), but it compartmentalises it in an easy to use third party package that I would hope would be maintained (fingers crossed) without me having to update functionality to cater for newer versions of different packages / browsers.