(Visual FoxPro) OneDrive -- Streaming REST Download to File

Downloads the contents of a DriveItem directly to a file in the local filesystem using the Chilkat REST class.

Note: This example requires Chilkat v9.5.0.69 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loRest
LOCAL lnSuccess
LOCAL loOauth2
LOCAL lcUriPath
LOCAL lnStatusCode
LOCAL loDiscard
LOCAL loRedirectUrl
LOCAL loSbJson
LOCAL loJsonErr
LOCAL lcLocalPath
LOCAL loStream

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

loRest = CreateObject('Chilkat_9_5_0.Rest')

* Use your previously obtained access token here:
* See the following examples for getting an access token:
*    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
*    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
*    Refresh Access Token (Azure AD v2.0 Endpoint).
*    Refresh Access Token (Azure AD Endpoint).

* First connect to graph.microsoft.com.  If there's a connectivity problem, we'll find out here.
lnSuccess = loRest.Connect("graph.microsoft.com",443,1,1)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    CANCEL
ENDIF

* (Make sure your token was obtained with the FilesRead or Files.ReadWrite scope.)
loOauth2 = CreateObject('Chilkat_9_5_0.OAuth2')
loOauth2.AccessToken = "MICROSOFT_GRAPH_ACCESS_TOKEN"
loRest.SetAuthOAuth2(loOauth2)

* Send the GET request to download the file.
lcUriPath = "/v1.0/me/drive/root:/Misc/wildlife/penguins.jpg:/content"
lnSuccess = loRest.SendReqNoBody("GET",lcUriPath)
IF (loRest.LastMethodSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loOauth2
    CANCEL
ENDIF

* NOTE: This way of doing the HTTP GET (i.e. download) may be more cumbersome, but it 
* allows for finer control of handling errors.  The connection establishment, the sending of the
* request, the reading of the response header, and the reading of the response body (i.e. the file data)
* are handled by separate method calls.  If the response header indicates an error, we can read
* the response body and treat it differently than if reading the file data.

* Read the response header.
lnStatusCode = loRest.ReadResponseHeader()
? "Response Status Code = " + STR(lnStatusCode)
IF (lnStatusCode = 302) THEN
    * This is a redirect.  Read the response body, if any, and then follow the redirect.
    * Usually the response body will be empty for a redirect, but we need to be sure to read
    * the response body just in case it exists.
    loDiscard = CreateObject('Chilkat_9_5_0.BinData')
    loRest.ReadRespBd(loDiscard)
    loRest.Disconnect(10)

    * For OneDrive, the redirect URL does not need authorization because the only way
    * to have obtained the direct download URL is from an authenticated request.
    * In fact, if we leave the authentication present, the GET request to the redirect URL will fail.

    * Note: The ClearAuth method is introduced in v9.5.0.69.
    loRest.ClearAuth()

    * Follow the redirect URL...
    loRedirectUrl = loRest.RedirectUrl()
    ? "Redirect Host: " + loRedirectUrl.Host
    ? "Redirect URI Path: " + loRedirectUrl.PathWithQueryParams

    lnSuccess = loRest.Connect(loRedirectUrl.Host,loRedirectUrl.Port,loRedirectUrl.Ssl,1)
    IF (lnSuccess <> 1) THEN
        ? loRest.LastErrorText
        RELEASE loRest
        RELEASE loOauth2
        RELEASE loDiscard
        CANCEL
    ENDIF

    * Send the request..
    lnSuccess = loRest.SendReqNoBody("GET",loRedirectUrl.Path)
    RELEASE loRedirectUrl
    IF (loRest.LastMethodSuccess <> 1) THEN
        ? loRest.LastErrorText
        RELEASE loRest
        RELEASE loOauth2
        RELEASE loDiscard
        CANCEL
    ENDIF

    lnStatusCode = loRest.ReadResponseHeader()
    ? loRest.LastErrorText
    ? "Redirect Response Status Code = " + STR(lnStatusCode)

ENDIF

IF (lnStatusCode >= 300) THEN

    * Read the error response body.
    loSbJson = CreateObject('Chilkat_9_5_0.StringBuilder')
    lnSuccess = loRest.ReadRespSb(loSbJson)
    IF (lnSuccess <> 1) THEN
        ? loRest.LastErrorText
        RELEASE loRest
        RELEASE loOauth2
        RELEASE loDiscard
        RELEASE loSbJson
        CANCEL
    ENDIF

    loJsonErr = CreateObject('Chilkat_9_5_0.JsonObject')
    loJsonErr.EmitCompact = 0
    loJsonErr.LoadSb(loSbJson)
    ? loJsonErr.Emit()

    RELEASE loRest
    RELEASE loOauth2
    RELEASE loDiscard
    RELEASE loSbJson
    RELEASE loJsonErr
    CANCEL
ENDIF

* Stream the response body directly to a local file.
lcLocalPath = "qa_output/penguins.jpg"

loStream = CreateObject('Chilkat_9_5_0.Stream')
loStream.SinkFile = lcLocalPath

lnSuccess = loRest.ReadRespBodyStream(loStream,1)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loOauth2
    RELEASE loDiscard
    RELEASE loSbJson
    RELEASE loJsonErr
    RELEASE loStream
    CANCEL
ENDIF

? "Successfully streamed a OneDrive file to the local filesystem."

RELEASE loRest
RELEASE loOauth2
RELEASE loDiscard
RELEASE loSbJson
RELEASE loJsonErr
RELEASE loStream