(Xojo Plugin) Download File (Stream to Local Filesystem)

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

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

Dim success As Boolean
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.

Dim gAuth As New Chilkat.AuthGoogle
gAuth.AccessToken = "GOOGLE_DRIVE_ACCESS_TOKEN"

Dim rest As 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.
Dim bAutoReconnect As Boolean
bAutoReconnect = True
success = rest.Connect("www.googleapis.com",443,True,bAutoReconnect)

// Provide the authentication credentials (i.e. the access token)
success = 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.
Dim gdCache As New Chilkat.Cache
gdCache.Level = 0
gdCache.AddRoot "C:/ckCache/googleDrive"

Dim fileId As String
fileId = gdCache.FetchText("testFolder/abc/123/penguins.jpg")
If (gdCache.LastMethodSuccess <> True) Then
    System.DebugLog("Filepath not found in cache.")
    Return
End If

// 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.
Dim sbPath As New Chilkat.StringBuilder
success = sbPath.Append("/drive/v3/files/")
success = sbPath.Append(fileId)
success = rest.AddQueryParam("alt","media")

// Create a stream object with a SinkFile set to the path where the downloaded file will go.
Dim fileStream As 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.  
success = rest.SetResponseBodyStream(200,True,fileStream)

// Download the file, streaming the content to the SinkFile.
Dim jsonResponse As String
jsonResponse = rest.FullRequestNoBody("GET",sbPath.GetAsString())
If (rest.LastMethodSuccess <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

// A successful response will have a status code equal to 200.
If (rest.ResponseStatusCode <> 200) Then
    System.DebugLog("response status code = " + Str(rest.ResponseStatusCode))
    System.DebugLog("response status text = " + rest.ResponseStatusText)
    System.DebugLog("response header: " + rest.ResponseHeader)
    Return
End If

System.DebugLog("File downloaded.")