Dropbox Component

Properties Methods Events Configuration Settings Errors

The Dropbox component provide an easy way to upload, download, and manage files and folders with Dropbox.

Syntax

nsoftware.InCloudStorage.Dropbox

Remarks

The Dropbox component provides a simple interface to working with Dropbox. Capabilities include uploading and downloading files, strong encryption support, creating folders, moving and copying resource, and more.

To begin, first create an account and register your application with Dropbox. Consult the Dropbox documentation for instructions on this process.

Authentication

Authentication is performed via OAuth 2.0. Use the OAuth component included in the toolkit, or any other OAuth implementation to perform authentication and retrieve an authorization string. Once you've obtained an authorization string like:

Bearer ya29.AHES6ZSZEJzATdZYjeihDn5W-VrXSsxEZu5p0pclxGdKKQ

Assign this value to the Authorization property before attempting any operations. Consult the Dropbox documentation for this particular service for more information about supported scope values and more details on OAuth authentication.

Listing Resources

ListResources lists resources within the account at the specified path.

Before calling this method set ResourcePath to the full path to the folder to list. If ResourcePath is unspecified the root folder contents will be listed.

After calling this method set ResourceIndex to a value from 0 to ResourceCount - 1. Setting ResourceIndex populates other Resource properties to provide information about the resource.

After calling this method the following resource properties are populated:

If the ResourceType is 1 (rtFolder) only the following properties are applicable:

If the results are paged, the ResourceMarker property will be populated. Call this method again to retrieve the next page of results. When the last page of results is returned ResourceMarker will be empty.

By default only resources of the specified ResourcePath are returned. To list files included within subfolders set RecurseSubfolders to True.

dropbox.ResourcePath = "/New Folder";
dropbox.ListResources();
for (int i = 0; i < dropbox.ResourceCount; i++)
{
  dropbox.ResourceIndex = i;
  Console.WriteLine(dropbox.ResourceName + ": " + dropbox.ResourceSize);
}

Downloading Files

The DownloadFile method downloads a specific file.

Set ResourcePath to the absolute path of the file to download before calling this method. The file will be downloaded to the stream specified (if any) by SetDownloadStream. If a stream is not specified and LocalFile is set the file will be saved to the specified location. If a stream is not specified and LocalFile is not set the file data will be held by ResourceData.

To decrypt an encrypted file set EncryptionAlgorithm and EncryptionPassword before calling this method.

dropbox.ResourcePath = "/My Folder/photos.zip"
dropbox.LocalFile = "../MyFile.zip";
dropbox.DownloadFile();

Resuming Downloads

The component also supports resuming failed downloads by using the StartByte property. If the download was interrupted, set StartByte to the appropriate offset before calling this method to resume the download.

dropbox.ResourcePath = myRemoteFile;
dropbox.LocalFile = downloadFile;
dropbox.DownloadFile();

//The transfer is interrupted and DownloadFile() above fails. Later, resume the download:

//Get the size of the partially download file
dropbox.StartByte = new FileInfo(downloadFile).Length; 
dropbox.ResourcePath = myRemoteFile;
dropbox.LocalFile = downloadFile;
dropbox.DownloadFile();

Resuming Encrypted File Downloads

Resuming encrypted file downloads is only supported when LocalFile was set in the initial download attempt. When beginning an encrypted download if LocalFile is set the component will create a temporary file in TempPath to hold the encrypted data until it is complete.

If the download is interrupted DownloadTempFile will be populated with the temporary file holding the partial data. When resuming, DownloadTempFile must be populated along with StartByte to allow the remainder of the encrypted data to be downloaded. Once the encrypted data is downloaded it will be decrypted and written to LocalFile.

dropbox.ResourcePath = myRemoteFile;
dropbox.LocalFile = downloadFile;
dropbox.EncryptionPassword = "password";
dropbox.DownloadFile();

//The transfer is interrupted and DownloadFile() above fails. Later, resume the download:

//Get the size of the partially download temp file
dropbox.StartByte = new FileInfo(dropbox.Config("DownloadTempFile")).Length; 
dropbox.ResourcePath = myRemoteFile;
dropbox.LocalFile = downloadFile;
dropbox.EncryptionPassword = "password";
dropbox.DownloadFile();

Uploading Files

LocalFile specifies the file to upload. The data to upload may also be set in ResourceData or set by SetUploadStream.

The FileName parameter of UploadFile specifies the name of the file to be written.

A file can be uploaded to a specific folder by specifying the absolute path in the FileName parameter, or by setting ResourcePath to the folder. Absolute paths begin with a "/" character and must include the full path beginning at the root. For instance:

//Upload to the root folder
  dropbox.ResourcePath = ""; 
  string path = dropbox.UploadFile("test.txt");
  //path is "/test.txt"

//Upload to a folder (relative path)
  dropbox.CreateFolder("/uploadtest");
  path = dropbox.UploadFile("test.txt");
  //path is "/uploadtest/test.txt"

//Upload to a folder (absolute path)
  path = dropbox.UploadFile("/uploadtest/test.txt");
  //path is "/uploadtest/test.txt"

To encrypt a file before uploading set EncryptionAlgorithm and EncryptionPassword.

When the upload is complete the component will fire the UploadComplete event and UploadFile returns the absolute path to the uploaded file.

Upload Notes

Dropbox offers two ways to upload a file. For smaller files a simple upload option is provided to upload data in one request. This is the default option. For larger files uploads can be fragmented into multiple pieces, allowing resuming of uploads that may be interrupted.

Simple

By default the component uses the simple upload mechanism. Simple uploads are the only supported option when SetUploadStream is used.

dropbox.LocalFile = "../MyFile.zip";
dropbox.UploadFile("/folder/MyFile.zip");

The following properties are applicable when calling UploadFile and UseResumableUpload if False (default - simple upload):

Resumable

To enable resumable uploads set UseResumableUpload to True. This is recommended for large files. The component will automatically fragment the specified file into smaller pieces and upload each individually. FragmentSize may be set to specify the size of the fragment if desired. The default fragment size is 10 MB.

When UseResumableUpload is set to True and UploadFile is called a resumable upload session is started by the component. UploadSessionId is populated with the Id of the session. This value may be needed for additional operations if the upload does not complete normally. Additionally StartByte is updated as necessary by the component to indicate the current offset in the file.

If the upload is interrupted for any reason the upload may be resumed. To resume an upload verify that UploadSessionId and StartByte are populated. If the same instance of the component is used these should already be populated and no special action is needed. Call UploadFile again to resume the upload at the specified StartByte offset.

The FragmentComplete event fires after each fragment is uploaded to indicate overall progress.

dropbox.LocalFile = "../MyFile.zip";
dropbox.UploadFile("MyFile.zip");

//The transfer is interrupted and UploadFile() above fails. Later, resume the download.
//Using the same instance StartByte and UploadSessionId are already populated 
//from the previous upload attempt
dropbox.UploadFile("MyFile.zip");

The following properties are applicable when calling UploadFile and UseResumableUpload if True:

Additional Functionality

The Dropbox component offers advanced functionality beyond simple uploads and downloads. For instance:

Encrypt and decrypt files using EncryptionAlgorithm and EncryptionPassword.
Use CopyResource, MoveResource, and DeleteResource to manage files and folders.
ShareResource creates shareable links to content.
ListChanges lists all changes in a folder from a given point to facilitate syncing local and remote copies.
Search can be used to search for matching content.
Revisions are supported through ListRevisions and RestoreResource.
GetUsageInfo and GetAccountInfo provide usage and account information.
GetPreview and GetThumbnail retrieve preview information for files.
And more!

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.


Account	This property defines information about the account.
Authorization	OAuth 2.0 Authorization Token.
ChangeMarker	A marker identifying the last change in a folder.
EncryptionAlgorithm	The encryption algorithm.
EncryptionPassword	The encryption password.
Firewall	A set of properties related to firewall access.
LocalFile	The location of the local file.
LocalHost	The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
Overwrite	Whether to overwrite the local or remote file.
Proxy	A set of properties related to proxy access.
ResourceCount	The number of files and folders.
ResourceData	Holds the file data after downloading or sets the file data before uploading or updating.
ResourceId	A unique identifier for the resource.
ResourceIndex	Selects the file or folder.
ResourceMarker	A marker when list results are paged.
ResourceModifiedDate	The last time the resource was modified on Dropbox.
ResourceName	The name of the resource.
ResourcePath	The path of the current resource.
ResourceRevision	The current revision of the file.
ResourceSize	The size of the resource in bytes.
ResourceType	Indicates whether the current entry is a folder or a file.
SearchMarker	A marker when searches are paged.
SearchMode	The level at which to search.
SharedResources	A collection of information about the shared resource(s).
SSLAcceptServerCert	Instructs the component to unconditionally accept the server certificate that matches the supplied certificate.
SSLCert	The certificate to be used during SSL negotiation.
SSLServerCert	The server certificate for the last established connection.
StartByte	The byte offset from which to start the upload or download.
ThumbnailFormat	The thumbnail format.
ThumbnailSize	The size of the thumbnail in pixels.
Timeout	A timeout for the component.
TotalSpace	The total allowed space in bytes.
UploadSessionId	The Id of the resumable upload session.
UsedSpace	The amount of space used in bytes.
UseResumableUpload	Whether to use resumable uploads.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.


Config	Sets or retrieves a configuration setting .
CopyResource	Copies the file or folder specified by ResourcePath to a new location.
CreateFolder	Creates the folder at the specified path.
DeleteResource	Deletes the specified resource.
DownloadFile	Downloads the specified file.
GetAccountInfo	Gets information about the account.
GetPreview	This method download a preview of a resource.
GetResourceInfo	Gets information about the specified resource.
GetThumbnail	Gets a thumbnail image.
GetUsageInfo	Gets the total space allowed and used.
Interrupt	Interrupt the current method.
ListChanges	List recent changes to a folder.
ListResources	Lists the resources in the current folder.
ListRevisions	Lists file revisions.
ListSharedResources	This method lists information about the shared resources.
MoveResource	Moves the file or folder specified by ResourcePath to a new location.
RestoreResource	Restores a file to a previous revision.
Search	Searches for files and folders matching the query.
SetDownloadStream	Sets the stream to which the downloaded file will be written.
SetUploadStream	Sets the stream from which data is read when uploading.
ShareResource	Shares a resource.
UnshareResource	This method un-shares the resource.
UploadFile	Uploads a file.
WaitForChanges	This method waits for changes to a folder for a specified period of time.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.


EndTransfer	Fired when a document finishes transferring.
Error	Information about errors during data delivery.
FragmentComplete	This event fires after each fragment of a resumable upload is completed.
ResourceList	Fired for each resource listed.
SearchResult	Fired for each search result.
SharedResourceList	This event fires when ListSharedResources is called.
SSLServerAuthentication	Fired after the server presents its certificate to the client.
SSLStatus	Shows the progress of the secure connection.
StartTransfer	Fired when a document starts transferring (after the headers).
Transfer	Fired while a document transfers (delivers document).
UploadComplete	Fires after an upload completes.

Configuration Settings

The following is a list of configuration settings for the component with short descriptions. Click on the links for further details.


DownloadTempFile	The temporary file used when downloading encrypted data.
FragmentSize	The fragment size.
MaxResults	The maximum number of search results per page.
PermanentlyDelete	Whether to permanently delete a resource.
RecurseSubfolders	Whether to recurse subfolders when listing resources.
RenameIfExists	Whether to rename the uploaded file if it exists.
ResourceClientDate	The client modified date.
ShortURL	Whether to use a shortened URL for the shared resource.
TempPath	The path to the directory where temporary files are created.
EncryptionIV	The initialization vector to be used for encryption/decryption.
EncryptionKey	The key to use during encryption/decryption.
XPath	Provides a way to point to a specific element in the returned XML response.
XElement	The name of the current element.
XParent	The parent of the current element.
XSubTree	A snapshot of the current element in the document.
XText	The text of the current element.
XChildCount	The number of child elements of the current element.
XChildName[x]	The name of the child element.
XChildXText[x]	The inner text of the child element.
AcceptEncoding	Used to tell the server which types of content encodings the client supports.
AllowHTTPCompression	This property enables HTTP compression for receiving data.
AllowIdenticalRedirectURL	Allow redirects to the same URL.
Append	Whether to append data to LocalFile.
Authorization	The Authorization string to be sent to the server.
BytesTransferred	Contains the number of bytes transferred in the response data.
EncodeURL	If set to true the URL will be encoded by the component.
FollowRedirects	Determines what happens when the server issues a redirect.
GetOn302Redirect	If set to true the component will perform a GET on the new location.
HTTPVersion	The version of HTTP used by the component.
IfModifiedSince	A date determining the maximum age of the desired document.
KeepAlive	Determines whether the HTTP connection is closed after completion of the request.
MaxRedirectAttempts	Limits the number of redirects that are followed in a request.
OtherHeaders	Other headers as determined by the user (optional).
ProxyAuthorization	The authorization string to be sent to the proxy server.
ProxyAuthScheme	The authorization scheme to be used for the proxy.
ProxyPassword	A password if authentication is to be used for the proxy.
ProxyPort	Port for the proxy server (default 80).
ProxyServer	Name or IP address of a proxy server (optional).
ProxyUser	A user name if authentication is to be used for the proxy.
TransferredDataLimit	The maximum number of incoming bytes to be stored by the component.
TransferredHeaders	The full set of headers as received from the server.
UseChunkedEncoding	Enables or Disables HTTP chunked encoding for transfers.
ChunkSize	Specifies the chunk size in bytes when using chunked encoding.
UserAgent	Information about the user agent (browser).
KerberosSPN	The Service Principal Name for the Kerberos Domain Controller.
ConnectionTimeout	Sets a separate timeout value for establishing a connection.
FirewallAutoDetect	Tells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallHost	Name or IP address of firewall (optional).
FirewallPassword	Password to be used if authentication is to be used when connecting through the firewall.
FirewallPort	The TCP port for the FirewallHost;.
FirewallType	Determines the type of firewall to connect through.
FirewallUser	A user name if authentication is to be used connecting through a firewall.
KeepAliveTime	The inactivity time in milliseconds before a TCP keep-alive packet is sent.
KeepAliveInterval	The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
Linger	When set to True, connections are terminated gracefully.
LingerTime	Time in seconds to have the connection linger.
LocalHost	The name of the local host through which connections are initiated or accepted.
LocalPort	The TCP port in the local host where the component binds.
MaxLineLength	The maximum amount of data to accumulate when no EOL is found.
MaxTransferRate	The transfer rate limit in bytes per second.
RecordLength	The length of received data records.
TCPKeepAlive	Determines whether or not the keep alive socket option is enabled.
UseIPv6	Whether to use IPv6.
TcpNoDelay	Whether or not to delay when sending packets.
ReuseSSLSession	Determines if the SSL session is reused.
SSLCipherStrength	The minimum cipher strength used for bulk encryption.
SSLEnabledProtocols	Used to enable/disable the supported security protocols.
SSLProvider	The name of the security provider to use.
SSLSecurityFlags	Flags that control certificate verification.
OpenSSLCADir	The path to a directory containing CA certificates.
OpenSSLCAFile	Name of the file containing the list of CA's trusted by your application.
OpenSSLCipherList	A string that controls the ciphers to be used by SSL.
OpenSSLPrngSeedData	The data to seed the pseudo random number generator (PRNG).
AbsoluteTimeout	Determines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallData	Used to send extra data to the firewall.
InBufferSize	The size in bytes of the incoming queue of the socket.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
CodePage	The system code page used for Unicode to Multibyte translations.