CODEWITHSUNDEEP
javascriptpostdownload
Constantinius
Constantinius

Reputation: 35059

Downloading files via POST

I'm interfacing a WCS service and have to send HTTP POST requests with XML to the server to retrieve (binary) raster files.

I managed to download the file with a jQuery ajax, but I cannot save the actual file content to the local file system.

Is there any way to achieve this? Preferably I'd like to use the browsers built-in download manager to handle the download.

Upvotes: 2

Views: 4126

Answers (1)

KrisWebDev
KrisWebDev

Reputation: 9492

Yes, it is possible to save files from Javascript. Basically it generates a blob containing the binary data, then it creates a link to this blob with the HTML5 "download" attribute in order to specify the desired filename, and finally it simulates a click on this link.

// Limited browser support! (latest release versions of Firefox & Chrome are OK)
var DownloadAttributeSupport = 'download' in document.createElement('a');
function showSave(data, name, mimetype) {
    var blob, url, builder = new BlobBuilder();
    builder.append(data);
    if (!mimetype) mimetype = "application/octet-stream";
    if (DownloadAttributeSupport) {
        blob = builder.getBlob(mimetype);
        url = URL.createObjectURL(blob);
        var link = document.createElement("a");
        link.setAttribute("href",url);
        link.setAttribute("download",name||"Download.bin");
        // Now I need to simulate a click on the link.
        // IE 10 has the better msSaveBlob method and older IE versions do not support the BlobBuilder interface
        // and object URLs, so we don't need the MS way to build an event object here.
        var event = document.createEvent('MouseEvents');
        event.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
        link.dispatchEvent(event);
}

You shoudlk look at https://stackoverflow.com/a/13059556/2227298 for a more complete answer regarding alternative codes for browsers not supporting HTML5 <a download>

Upvotes: 2

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