Cloud Storage for Firebase allows you to quickly and easily upload files to a Cloud Storage bucket provided and managed by Firebase.
Create a Reference
To upload a file, first create a Cloud Storage reference to the location in Cloud Storage you want to upload the file to.
You can create a reference by appending child paths to the root of your Cloud Storage bucket:
Swift
// Create a root reference let storageRef = storage . reference () // Create a reference to "mountains.jpg" let mountainsRef = storageRef . child ( "mountains.jpg" ) // Create a reference to 'images/mountains.jpg' let mountainImagesRef = storageRef . child ( "images/mountains.jpg" ) // While the file names are the same, the references point to different files mountainsRef . name == mountainImagesRef . name // true mountainsRef . fullPath == mountainImagesRef . fullPath // false
Objective-C
// Create a root reference FIRStorageReference * storageRef = [ storage reference ]; // Create a reference to "mountains.jpg" FIRStorageReference * mountainsRef = [ storageRef child : @"mountains.jpg" ]; // Create a reference to 'images/mountains.jpg' FIRStorageReference * mountainImagesRef = [ storageRef child : @"images/mountains.jpg" ]; // While the file names are the same, the references point to different files [ mountainsRef . name isEqualToString : mountainImagesRef . name ]; // true [ mountainsRef . fullPath isEqualToString : mountainImagesRef . fullPath ]; // false
You cannot upload data with a reference to the root of your Cloud Storage bucket. Your reference must point to a child URL.
Upload Files
Once you have a reference, you can upload files to Cloud Storage in two ways:
- Upload from data in memory
- Upload from a URL representing a file on device
Upload from data in memory
The putData:metadata:completion:
method is the simplest way to upload a file
to Cloud Storage
. putData:metadata:completion:
takes an NSData
object and returns an FIRStorageUploadTask
, which you can use to manage your
upload and monitor its status.
Swift
// Data in memory let data = Data () // Create a reference to the file you want to upload let riversRef = storageRef . child ( "images/rivers.jpg" ) // Upload the file to the path "images/rivers.jpg" let uploadTask = riversRef . putData ( data , metadata : nil ) { ( metadata , error ) in guard let metadata = metadata else { // Uh-oh, an error occurred! return } // Metadata contains file metadata such as size, content-type. let size = metadata . size // You can also access to download URL after upload. riversRef . downloadURL { ( url , error ) in guard let downloadURL = url else { // Uh-oh, an error occurred! return } } }
Objective-C
// Data in memory NSData * data = [ NSData dataWithContentsOfFile : @"rivers.jpg" ]; // Create a reference to the file you want to upload FIRStorageReference * riversRef = [ storageRef child : @"images/rivers.jpg" ]; // Upload the file to the path "images/rivers.jpg" FIRStorageUploadTask * uploadTask = [ riversRef putData : data metadata : nil completion : ^ ( FIRStorageMetadata * metadata , NSError * error ) { if ( error != nil ) { // Uh-oh, an error occurred! } else { // Metadata contains file metadata such as size, content-type, and download URL. int size = metadata . size ; // You can also access to download URL after upload. [ riversRef downloadURLWithCompletion :^ ( NSURL * _Nullable URL , NSError * _Nullable error ) { if ( error != nil ) { // Uh-oh, an error occurred! } else { NSURL * downloadURL = URL ; } }]; } }];
Upload from a local file
You can upload local files on the devices, such as photos and videos from the
camera, with the putFile:metadata:completion:
method. putFile:metadata:completion:
takes an NSURL
and returns an FIRStorageUploadTask
, which you can use to manage your upload and monitor its
status.
Swift
// File located on disk let localFile = URL ( string : "path/to/image" ) ! // Create a reference to the file you want to upload let riversRef = storageRef . child ( "images/rivers.jpg" ) // Upload the file to the path "images/rivers.jpg" let uploadTask = riversRef . putFile ( from : localFile , metadata : nil ) { metadata , error in guard let metadata = metadata else { // Uh-oh, an error occurred! return } // Metadata contains file metadata such as size, content-type. let size = metadata . size // You can also access to download URL after upload. riversRef . downloadURL { ( url , error ) in guard let downloadURL = url else { // Uh-oh, an error occurred! return } } }
Objective-C
// File located on disk NSURL * localFile = [ NSURL URLWithString : @"path/to/image" ]; // Create a reference to the file you want to upload FIRStorageReference * riversRef = [ storageRef child : @"images/rivers.jpg" ]; // Upload the file to the path "images/rivers.jpg" FIRStorageUploadTask * uploadTask = [ riversRef putFile : localFile metadata : nil completion :^ ( FIRStorageMetadata * metadata , NSError * error ) { if ( error != nil ) { // Uh-oh, an error occurred! } else { // Metadata contains file metadata such as size, content-type, and download URL. int size = metadata . size ; // You can also access to download URL after upload. [ riversRef downloadURLWithCompletion :^ ( NSURL * _Nullable URL , NSError * _Nullable error ) { if ( error != nil ) { // Uh-oh, an error occurred! } else { NSURL * downloadURL = URL ; } }]; } }];
If you want to actively manage your upload, you can use the putData:
or putFile:
methods and observe the upload task, rather than using the
completion handler. See Manage Uploads
for more
information.
Add File Metadata
You can also include metadata when you upload files.
This metadata contains typical file metadata properties such as name
, size
,
and contentType
(commonly referred to as MIME type). The putFile:
method
automatically infers the content type from the NSURL
filename extension, but
you can override the auto-detected type by specifying contentType
in the
metadata. If you do not provide a contentType
and Cloud Storage
cannot infer a default from the file extension, Cloud Storage
uses application/octet-stream
. See the Use File Metadata
section for more information about file metadata.
Swift
// Create storage reference let mountainsRef = storageRef . child ( "images/mountains.jpg" ) // Create file metadata including the content type let metadata = StorageMetadata () metadata . contentType = "image/jpeg" // Upload data and metadata mountainsRef . putData ( data , metadata : metadata ) // Upload file and metadata mountainsRef . putFile ( from : localFile , metadata : metadata )
Objective-C
// Create storage reference FIRStorageReference * mountainsRef = [ storageRef child : @"images/mountains.jpg" ]; // Create file metadata including the content type FIRStorageMetadata * metadata = [[ FIRStorageMetadata alloc ] init ]; metadata . contentType = @"image/jpeg" ; // Upload data and metadata FIRStorageUploadTask * uploadTask = [ mountainsRef putData : data metadata : metadata ]; // Upload file and metadata uploadTask = [ mountainsRef putFile : localFile metadata : metadata ];
Manage Uploads
In addition to starting uploads, you can pause, resume, and cancel uploads using
the pause
, resume
, and cancel
methods. These methods raise pause
, resume
, and cancel
events. Canceling an upload causes the upload to fail
with an error indicating that the upload was canceled.
Swift
// Start uploading a file let uploadTask = storageRef . putFile ( from : localFile ) // Pause the upload uploadTask . pause () // Resume the upload uploadTask . resume () // Cancel the upload uploadTask . cancel ()
Objective-C
// Start uploading a file FIRStorageUploadTask * uploadTask = [ storageRef putFile : localFile ]; // Pause the upload [ uploadTask pause ]; // Resume the upload [ uploadTask resume ]; // Cancel the upload [ uploadTask cancel ];
Monitor Upload Progress
You can attach observers to FIRStorageUploadTask
s in order to monitor the
progress of the upload. Adding an observer returns a FIRStorageHandle
that can be used to remove the observer.
Swift
// Add a progress observer to an upload task let observer = uploadTask . observe (. progress ) { snapshot in // A progress event occured }
Objective-C
// Add a progress observer to an upload task NSString * observer = [ uploadTask observeStatus : FIRStorageTaskStatusProgress handler : ^ ( FIRStorageTaskSnapshot * snapshot ) { // A progress event occurred }];
These observers can be added to an FIRStorageTaskStatus
event:
FIRStorageTaskStatus
Event |
Typical Usage |
|---|---|
FIRStorageTaskStatusResume
|
This event fires when the task starts or resumes uploading, and is often used in conjunction with the FIRStorageTaskStatusPause
event. |
FIRStorageTaskStatusProgress
|
This event fires any time data is uploading to Cloud Storage , and can be used to populate an upload progress indicator. |
FIRStorageTaskStatusPause
|
This event fires any time the upload is paused, and is often used in conjunction with the FIRStorageTaskStatusResume
event. |
FIRStorageTaskStatusSuccess
|
This event fires when a upload has completed successfully. |
FIRStorageTaskStatusFailure
|
This event fires when a upload has failed. Inspect the error to determine the failure reason. |
When an event occurs, an FIRStorageTaskSnapshot
object is passed back. This
snapshot is an immutable view of the task, at the time the event occurred.
This object contains the following properties:
| Property | Type | Description |
|---|---|---|
progress
|
NSProgress
|
An NSProgress
object containing the progress of the upload. |
error
|
NSError
|
An error that occurred during upload, if any. |
metadata
|
FIRStorageMetadata
|
During upload contains metadata being uploaded. After an FIRTaskStatusSuccess
event, contains the uploaded file's metadata. |
task
|
FIRStorageUploadTask
|
The task this is a snapshot of, which can be used to manage ( pause
, resume
, cancel
) the task. |
reference
|
FIRStorageReference
|
The reference this task came from. |
You can also remove observers, either individually, by status, or by removing all of them.
Swift
// Create a task listener handle let observer = uploadTask . observe (. progress ) { snapshot in // A progress event occurred } // Remove an individual observer uploadTask . removeObserver ( withHandle : observer ) // Remove all observers of a particular status uploadTask . removeAllObservers ( for : . progress ) // Remove all observers uploadTask . removeAllObservers ()
Objective-C
// Create a task listener handle NSString * observer = [ uploadTask observeStatus : FIRStorageTaskStatusProgress handler : ^ ( FIRStorageTaskSnapshot * snapshot ) { // A progress event occurred }]; // Remove an individual observer [ uploadTask removeObserverWithHandle : observer ]; // Remove all observers of a particular status [ uploadTask removeAllObserversForStatus : FIRStorageTaskStatusProgress ]; // Remove all observers [ uploadTask removeAllObservers ];
To prevent memory leaks, all observers are removed after an FIRStorageTaskStatusSuccess
or FIRStorageTaskStatusFailure
occurs.
Error Handling
There are a number of reasons why errors may occur on upload, including the local file not existing, or the user not having permission to upload the desired file. You can find more information about errors in the Handle Errors section of the docs.
Full Example
A full example of an upload with progress monitoring and error handling is shown below:
Swift
// Local file you want to upload let localFile = URL ( string : "path/to/image" ) ! // Create the file metadata let metadata = StorageMetadata () metadata . contentType = "image/jpeg" // Upload file and metadata to the object 'images/mountains.jpg' let uploadTask = storageRef . putFile ( from : localFile , metadata : metadata ) // Listen for state changes, errors, and completion of the upload. uploadTask . observe (. resume ) { snapshot in // Upload resumed, also fires when the upload starts } uploadTask . observe (. pause ) { snapshot in // Upload paused } uploadTask . observe (. progress ) { snapshot in // Upload reported progress let percentComplete = 100.0 * Double ( snapshot . progress !. completedUnitCount ) / Double ( snapshot . progress !. totalUnitCount ) } uploadTask . observe (. success ) { snapshot in // Upload completed successfully } uploadTask . observe (. failure ) { snapshot in if let error = snapshot . error as ? NSError { switch ( StorageErrorCode ( rawValue : error . code ) ! ) { case . objectNotFound : // File doesn't exist break case . unauthorized : // User doesn't have permission to access file break case . cancelled : // User canceled the upload break /* ... */ case . unknown : // Unknown error occurred, inspect the server response break default : // A separate error occurred. This is a good place to retry the upload. break } } }
Objective-C
// Local file you want to upload NSURL * localFile = [ NSURL URLWithString : @"path/to/image" ]; // Create the file metadata FIRStorageMetadata * metadata = [[ FIRStorageMetadata alloc ] init ]; metadata . contentType = @"image/jpeg" ; // Upload file and metadata to the object 'images/mountains.jpg' FIRStorageUploadTask * uploadTask = [ storageRef putFile : localFile metadata : metadata ]; // Listen for state changes, errors, and completion of the upload. [ uploadTask observeStatus : FIRStorageTaskStatusResume handler :^ ( FIRStorageTaskSnapshot * snapshot ) { // Upload resumed, also fires when the upload starts }]; [ uploadTask observeStatus : FIRStorageTaskStatusPause handler :^ ( FIRStorageTaskSnapshot * snapshot ) { // Upload paused }]; [ uploadTask observeStatus : FIRStorageTaskStatusProgress handler :^ ( FIRStorageTaskSnapshot * snapshot ) { // Upload reported progress double percentComplete = 100.0 * ( snapshot . progress . completedUnitCount ) / ( snapshot . progress . totalUnitCount ); }]; [ uploadTask observeStatus : FIRStorageTaskStatusSuccess handler :^ ( FIRStorageTaskSnapshot * snapshot ) { // Upload completed successfully }]; // Errors only occur in the "Failure" case [ uploadTask observeStatus : FIRStorageTaskStatusFailure handler :^ ( FIRStorageTaskSnapshot * snapshot ) { if ( snapshot . error != nil ) { switch ( snapshot . error . code ) { case FIRStorageErrorCodeObjectNotFound : // File doesn't exist break ; case FIRStorageErrorCodeUnauthorized : // User doesn't have permission to access file break ; case FIRStorageErrorCodeCancelled : // User canceled the upload break ; /* ... */ case FIRStorageErrorCodeUnknown : // Unknown error occurred, inspect the server response break ; } } }];
Now that you've uploaded files, let's learn how to download them from Cloud Storage .
