Angular 4.3: Getting an arraybuffer with new HttpClient

Question

I would like to change to the new HttpClient. Until now I handle file downloads the following:

getXlsx (): Observable {
    return this.http.get(\         


        

Answer 1

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.