CBLBlob

@interface CBLBlob : NSObject

A CBLBlob contains arbitrary binary data, tagged with a MIME type. Blobs can be arbitrarily large, and their data is loaded only on demand (when the content or contentStream properties are accessed), not when the document is loaded. The document’s raw JSON form only contains the CBLBlob’s metadata (type, length and a digest of the data) in a small object. The data itself is stored externally to the document, keyed by the digest.

  • Initializes a CBLBlob with the given in-memory data.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithContentType:(nonnull NSString *)contentType
                                       data:(nonnull NSData *)data;

    Parameters

    contentType

    The type of content this CBLBlob will represent.
    data

    The data that this CBLBlob will contain.

    Return Value

    The CBLBlob object.

  • Initializes a CBLBlob with the given stream of data.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithContentType:(nonnull NSString *)contentType
                              contentStream:(nonnull NSInputStream *)stream;

    Parameters

    contentType

    The type of content this CBLBlob will represent.
    stream

    The stream of data that this CBLBlob will consume.

    Return Value

    The CBLBlob object.

  • Initializes a CBLBlob with the contents of a file.

    Declaration

    Objective-C

    - (nullable instancetype)initWithContentType:(nonnull NSString *)contentType
                                     fileURL:(nonnull NSURL *)fileURL
                                       error:
                                           (NSError *_Nullable *_Nullable)error;

    Parameters

    contentType

    The type of content this CBLBlob will represent.
    fileURL

    A URL to a file containing the data that this CBLBlob will represent.
    error

    On return, the error if any.

    Return Value

    The CBLBlob object.

  • The -init method is not available.

    Declaration

    Objective-C

    - (nonnull instancetype)init;

  • Gets the contents of a CBLBlob as a block of memory. Not recommended for very large blobs, as it may be slow and use up lots of RAM.

    Declaration

    Objective-C

    @property (nonatomic, readonly, nullable) NSData *content;

  • A stream of the content of a CBLBlob. The caller is responsible for opening the stream, and closing it when finished.

    Declaration

    Objective-C

    @property (nonatomic, readonly, nullable) NSInputStream *contentStream;

  • The type of content this CBLBlob represents; by convention this is a MIME type.

    Declaration

    Objective-C

    @property (nonatomic, readonly, nullable) NSString *contentType;

  • The binary length of this CBLBlob.

    Declaration

    Objective-C

    @property (nonatomic, readonly) uint64_t length;

  • The cryptographic digest of this CBLBlob’s contents, which uniquely identifies it.

    Declaration

    Objective-C

    @property (nonatomic, readonly, nullable) NSString *digest;

  • The metadata associated with this CBLBlob

    Declaration

    Objective-C

    @property (nonatomic, readonly) NSDictionary<NSString *, id> *_Nonnull properties;

  • Returns a dictionary representation of the blob object in JSON string format. The dictionary will contain only metadata information without data.

    If Blob is not saved in the database which means that it doesn’t have digest information, calling toJSON() will not be allowed and it will throw an NSInternalInconsistencyException.

    Declaration

    Objective-C

    - (nonnull NSString *)toJSON;

  • Return whether the given dictionary represents Blob or not

    Declaration

    Objective-C

    + (BOOL)isBlob:(nonnull NSDictionary<NSString *, id> *)properties;