BlobClient class

Creates an instance of BlobClient. This method accepts an encoded URL or non-encoded URL pointing to a blob. Encoded URL string will NOT be escaped twice, only special characters in URL path will be escaped. If a blob name includes ? or %, blob name must be encoded in the URL.

new BlobClient(url: string, pipeline: PipelineLike)

Parameters

Creates an instance of BlobClient. This method accepts an encoded URL or non-encoded URL pointing to a blob. Encoded URL string will NOT be escaped twice, only special characters in URL path will be escaped. If a blob name includes ? or %, blob name must be encoded in the URL.

new BlobClient(url: string, credential?: StorageSharedKeyCredential | AnonymousCredential | TokenCredential, options?: StoragePipelineOptions)

Parameters

Creates an instance of BlobClient from connection string.

new BlobClient(connectionString: string, containerName: string, blobName: string, options?: StoragePipelineOptions)

Parameters

The name of the storage container the blob is associated with.

string containerName

Property Value

The name of the blob.

string name

Property Value

accountName: string

Property Value

Inherited From StorageClient.accountName

Such as AnonymousCredential, StorageSharedKeyCredential or any credential from the @azure/identity package to authenticate requests to the service. You can also provide an object that implements the TokenCredential interface. If not specified, AnonymousCredential is used.

credential: StorageSharedKeyCredential | AnonymousCredential | TokenCredential

Property Value

Inherited From StorageClient.credential

Encoded URL string value.

url: string

Property Value

Inherited From StorageClient.url

Aborts a pending asynchronous Copy Blob operation, and leaves a destination blob with zero length and full metadata. Version 2012-02-12 and newer.

See https://docs.microsoft.com/en-us/rest/api/storageservices/abort-copy-blob

function abortCopyFromURL(copyId: string, options?: BlobAbortCopyFromURLOptions): Promise<BlobAbortCopyFromURLResponse>

Parameters

Returns

Asynchronously copies a blob to a destination within the storage account. This method returns a long running operation poller that allows you to wait indefinitely until the copy is completed. You can also cancel a copy before it is completed by calling cancelOperation on the poller. Note that the onProgress callback will not be invoked if the operation completes in the first request, and attempting to cancel a completed copy will result in an error being thrown.

In version 2012-02-12 and later, the source for a Copy Blob operation can be a committed blob in any Azure storage account. Beginning with version 2015-02-21, the source for a Copy Blob operation can be an Azure file in any Azure storage account. Only storage accounts created on or after June 7th, 2012 allow the Copy Blob operation to copy from another storage account.

See https://docs.microsoft.com/en-us/rest/api/storageservices/copy-blob

Example using automatic polling:

const copyPoller = await blobClient.beginCopyFromURL('url');
const result = await copyPoller.pollUntilDone();

Example using manual polling:

const copyPoller = await blobClient.beginCopyFromURL('url');
while (!poller.isDone()) {
   await poller.poll();
}
const result = copyPoller.getResult();

Example using progress updates:

const copyPoller = await blobClient.beginCopyFromURL('url', {
  onProgress(state) {
    console.log(`Progress: ${state.copyProgress}`);
  }
});
const result = await copyPoller.pollUntilDone();

Example using a changing polling interval (default 15 seconds):

const copyPoller = await blobClient.beginCopyFromURL('url', {
  intervalInMs: 1000 // poll blob every 1 second for copy progress
});
const result = await copyPoller.pollUntilDone();

Example using copy cancellation:

const copyPoller = await blobClient.beginCopyFromURL('url');
// cancel operation after starting it.
try {
  await copyPoller.cancelOperation();
  // calls to get the result now throw PollerCancelledError
  await copyPoller.getResult();
} catch (err) {
  if (err.name === 'PollerCancelledError') {
    console.log('The copy was cancelled.');
  }
}

function beginCopyFromURL(copySource: string, options?: BlobBeginCopyFromURLOptions): Promise<PollerLikeWithCancellation<PollOperationState<BlobBeginCopyFromURLResponse>, BlobBeginCopyFromURLResponse>>

Parameters

Returns

Creates a read-only snapshot of a blob.

See https://docs.microsoft.com/en-us/rest/api/storageservices/snapshot-blob

function createSnapshot(options?: BlobCreateSnapshotOptions): Promise<BlobCreateSnapshotResponse>

Parameters

Returns

Marks the specified blob or snapshot for deletion. The blob is later deleted during garbage collection. Note that in order to delete a blob, you must delete all of its snapshots. You can delete both at the same time with the Delete Blob operation.

See https://docs.microsoft.com/en-us/rest/api/storageservices/delete-blob

function delete(options?: BlobDeleteOptions): Promise<BlobDeleteResponse>

Parameters

Returns

Marks the specified blob or snapshot for deletion if it exists. The blob is later deleted during garbage collection. Note that in order to delete a blob, you must delete all of its snapshots. You can delete both at the same time with the Delete Blob operation.

See https://docs.microsoft.com/en-us/rest/api/storageservices/delete-blob

function deleteIfExists(options?: BlobDeleteOptions): Promise<BlobDeleteIfExistsResponse>

Parameters

Returns

Delete the immutablility policy on the blob.

function deleteImmutabilityPolicy(options?: BlobDeleteImmutabilityPolicyOptions): Promise<BlobDeleteImmutabilityPolicyResponse>

Parameters

Returns

Reads or downloads a blob from the system, including its metadata and properties. You can also call Get Blob to read a snapshot.

• In Node.js, data returns in a Readable stream readableStreamBody
• In browsers, data returns in a promise blobBody

See https://docs.microsoft.com/en-us/rest/api/storageservices/get-blob

function download(offset?: number, count?: number, options?: BlobDownloadOptions): Promise<BlobDownloadResponseParsed>

Parameters

// Download and convert a blob to a string
const downloadBlockBlobResponse = await blobClient.download();
const downloaded = await streamToBuffer(downloadBlockBlobResponse.readableStreamBody);
console.log("Downloaded blob content:", downloaded.toString());

async function streamToBuffer(readableStream) {
return new Promise((resolve, reject) => {
const chunks = [];
readableStream.on("data", (data) => {
chunks.push(data instanceof Buffer ? data : Buffer.from(data));
});
readableStream.on("end", () => {
resolve(Buffer.concat(chunks));
});
readableStream.on("error", reject);
});
}

// Download and convert a blob to a string
const downloadBlockBlobResponse = await blobClient.download();
const downloaded = await blobToString(await downloadBlockBlobResponse.blobBody);
console.log(
  "Downloaded blob content",
  downloaded
);

async function blobToString(blob: Blob): Promise<string> {
  const fileReader = new FileReader();
  return new Promise<string>((resolve, reject) => {
    fileReader.onloadend = (ev: any) => {
      resolve(ev.target!.result);
    };
    fileReader.onerror = reject;
    fileReader.readAsText(blob);
  });
}

Returns

ONLY AVAILABLE IN NODE.JS RUNTIME.

Downloads an Azure Blob in parallel to a buffer. Offset and count are optional, downloads the entire blob if they are not provided.

Warning: Buffers can only support files up to about one gigabyte on 32-bit systems or about two gigabytes on 64-bit systems due to limitations of Node.js/V8. For blobs larger than this size, consider downloadToFile.

function downloadToBuffer(buffer: Buffer, offset?: number, count?: number, options?: BlobDownloadToBufferOptions): Promise<Buffer>

Parameters

Returns

ONLY AVAILABLE IN NODE.JS RUNTIME.

Downloads an Azure Blob in parallel to a buffer. Offset and count are optional, downloads the entire blob if they are not provided.

Warning: Buffers can only support files up to about one gigabyte on 32-bit systems or about two gigabytes on 64-bit systems due to limitations of Node.js/V8. For blobs larger than this size, consider downloadToFile.

function downloadToBuffer(offset?: number, count?: number, options?: BlobDownloadToBufferOptions): Promise<Buffer>

Parameters

Returns

ONLY AVAILABLE IN NODE.JS RUNTIME.

Downloads an Azure Blob to a local file. Fails if the the given file path already exits. Offset and count are optional, pass 0 and undefined respectively to download the entire blob.

function downloadToFile(filePath: string, offset?: number, count?: number, options?: BlobDownloadOptions): Promise<BlobDownloadResponseParsed>

Parameters

Returns

The response data for blob download operation, but with readableStreamBody set to undefined since its content is already read and written into a local file at the specified path.

Returns true if the Azure blob resource represented by this client exists; false otherwise.

NOTE: use this function with care since an existing blob might be deleted by other clients or applications. Vice versa new blobs might be added by other clients or applications after this function completes.

function exists(options?: BlobExistsOptions): Promise<boolean>

Parameters

Returns

Only available for BlobClient constructed with a shared key credential.

Generates string to sign for a Blob Service Shared Access Signature (SAS) URI based on the client properties and parameters passed in. The SAS is signed by the shared key credential of the client.

See https://docs.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas

function generateSasStringToSign(options: BlobGenerateSasUrlOptions): string

Parameters

Returns

The SAS URI consisting of the URI to the resource represented by this client, followed by the generated SAS token.

Only available for BlobClient constructed with a shared key credential.

Generates a Blob Service Shared Access Signature (SAS) URI based on the client properties and parameters passed in. The SAS is signed by the shared key credential of the client.

See https://docs.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas

function generateSasUrl(options: BlobGenerateSasUrlOptions): Promise<string>

Parameters

Returns

The SAS URI consisting of the URI to the resource represented by this client, followed by the generated SAS token.

The Get Account Information operation returns the sku name and account kind for the specified account. The Get Account Information operation is available on service versions beginning with version 2018-03-28.

See https://docs.microsoft.com/en-us/rest/api/storageservices/get-account-information

function getAccountInfo(options?: BlobGetAccountInfoOptions): Promise<BlobGetAccountInfoResponse>

Parameters

Returns

Response data for the Service Get Account Info operation.

Creates a AppendBlobClient object.

function getAppendBlobClient(): AppendBlobClient

Returns

Get a BlobLeaseClient that manages leases on the blob.

function getBlobLeaseClient(proposeLeaseId?: string): BlobLeaseClient

Parameters

Returns

A new BlobLeaseClient object for managing leases on the blob.

Creates a BlockBlobClient object.

function getBlockBlobClient(): BlockBlobClient

Returns

Creates a PageBlobClient object.

function getPageBlobClient(): PageBlobClient

Returns

Returns all user-defined metadata, standard HTTP properties, and system properties for the blob. It does not return the content of the blob.

See https://docs.microsoft.com/en-us/rest/api/storageservices/get-blob-properties

WARNING: The metadata object returned in the response will have its keys in lowercase, even if they originally contained uppercase characters. This differs from the metadata keys returned by the methods of ContainerClient that list blobs using the includeMetadata option, which will retain their original casing.

function getProperties(options?: BlobGetPropertiesOptions): Promise<BlobGetPropertiesResponse>

Parameters

Returns

Gets the tags associated with the underlying blob.

function getTags(options?: BlobGetTagsOptions): Promise<BlobGetTagsResponse>

Parameters

Returns

Sets the tier on a blob. The operation is allowed on a page blob in a premium storage account and on a block blob in a blob storage account (locally redundant storage only). A premium page blob's tier determines the allowed size, IOPS, and bandwidth of the blob. A block blob's tier determines Hot/Cool/Archive storage type. This operation does not update the blob's ETag.

See https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-tier

function setAccessTier(tier: string, options?: BlobSetTierOptions): Promise<BlobSetTierResponse>

Parameters

Returns

Sets system properties on the blob.

If no value provided, or no value provided for the specified blob HTTP headers, these blob HTTP headers without a value will be cleared.

See https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-properties

function setHTTPHeaders(blobHTTPHeaders?: BlobHTTPHeaders, options?: BlobSetHTTPHeadersOptions): Promise<BlobSetHTTPHeadersResponse>

Parameters

Returns

Set immutability policy on the blob.

function setImmutabilityPolicy(immutabilityPolicy: BlobImmutabilityPolicy, options?: BlobSetImmutabilityPolicyOptions): Promise<BlobSetImmutabilityPolicyResponse>

Parameters

Returns

Set legal hold on the blob.

function setLegalHold(legalHoldEnabled: boolean, options?: BlobSetLegalHoldOptions): Promise<BlobSetLegalHoldResponse>

Parameters

Returns

Sets user-defined metadata for the specified blob as one or more name-value pairs.

If no option provided, or no metadata defined in the parameter, the blob metadata will be removed.

See https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-metadata

function setMetadata(metadata?: Metadata, options?: BlobSetMetadataOptions): Promise<BlobSetMetadataResponse>

Parameters

Returns

Sets tags on the underlying blob. A blob can have up to 10 tags. Tag keys must be between 1 and 128 characters. Tag values must be between 0 and 256 characters. Valid tag key and value characters include lower and upper case letters, digits (0-9), space (' '), plus ('+'), minus ('-'), period ('.'), foward slash ('/'), colon (':'), equals ('='), and underscore ('_').

function setTags(tags: Tags, options?: BlobSetTagsOptions): Promise<BlobSetTagsResponse>

Parameters

Returns

The synchronous Copy From URL operation copies a blob or an internet resource to a new blob. It will not return a response until the copy is complete.

See https://docs.microsoft.com/en-us/rest/api/storageservices/copy-blob-from-url

function syncCopyFromURL(copySource: string, options?: BlobSyncCopyFromURLOptions): Promise<BlobCopyFromURLResponse>

Parameters

Returns

Restores the contents and metadata of soft deleted blob and any associated soft deleted snapshots. Undelete Blob is supported only on version 2017-07-29 or later.

See https://docs.microsoft.com/en-us/rest/api/storageservices/undelete-blob

function undelete(options?: BlobUndeleteOptions): Promise<BlobUndeleteResponse>

Parameters

Returns

Creates a new BlobClient object identical to the source but with the specified snapshot timestamp. Provide "" will remove the snapshot and return a Client to the base blob.

function withSnapshot(snapshot: string): BlobClient

Parameters

Returns

A new BlobClient object identical to the source but with the specified snapshot timestamp

Creates a new BlobClient object pointing to a version of this blob. Provide "" will remove the versionId and return a Client to the base blob.

function withVersion(versionId: string): BlobClient

Parameters

Returns

A new BlobClient object pointing to the version of this blob.