Node.js

Download File (Stream to Local Filesystem)

See more Google Drive Examples

This example demonstrates how to download the content of a file from Google Drive. The file is streamed to the local filesystem. Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    success = true;

    // It requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // This example uses a previously obtained access token having permission for the 
    // Google Drive scope.

    var gAuth = new chilkat.AuthGoogle();
    gAuth.AccessToken = "GOOGLE_DRIVE_ACCESS_TOKEN";

    var rest = new chilkat.Rest();

    // Connect using TLS.
    // A single REST object, once connected, can be used for many Google Drive REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    var bAutoReconnect = true;
    success = rest.Connect("www.googleapis.com",443,true,bAutoReconnect);

    // Provide the authentication credentials (i.e. the access token)
    rest.SetAuthGoogle(gAuth);

    // ------------------------------------------------------------------------------
    // To download a file, we must know the file ID.
    // In a previous example (see Build Local Metadata Cache
    // we built a local cache to make it easy to lookup file IDs given a file path.
    // Let's say we want to download "testFolder/abc/123/penguins.jpg".
    // First we lookup the fileId in the cache.  With the fileId, we can download the file.
    var gdCache = new chilkat.Cache();
    gdCache.Level = 0;
    gdCache.AddRoot("C:/ckCache/googleDrive");

    var fileId = gdCache.FetchText("testFolder/abc/123/penguins.jpg");
    if (gdCache.LastMethodSuccess !== true) {
        console.log("Filepath not found in cache.");
        return;
    }

    // We need to send a GET request like this:
    // GET https://www.googleapis.com/drive/v3/files/fileId?alt=media
    // The fileId is part of the path.
    var sbPath = new chilkat.StringBuilder();
    sbPath.Append("/drive/v3/files/");
    sbPath.Append(fileId);
    rest.AddQueryParam("alt","media");

    // Create a stream object with a SinkFile set to the path where the downloaded file will go.
    var fileStream = new chilkat.Stream();
    fileStream.SinkFile = "qa_output/penguins.jpg";
    // Indicate that the response body should stream directly to fileStream,
    // but only if the response status is 200.  
    rest.SetResponseBodyStream(200,true,fileStream);

    // Download the file, streaming the content to the SinkFile.
    var jsonResponse = rest.FullRequestNoBody("GET",sbPath.GetAsString());
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // A successful response will have a status code equal to 200.
    if (rest.ResponseStatusCode !== 200) {
        console.log("response status code = " + rest.ResponseStatusCode);
        console.log("response status text = " + rest.ResponseStatusText);
        console.log("response header: " + rest.ResponseHeader);
        return;
    }

    console.log("File downloaded.");

}

chilkatExample();