A Blob 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 Blob’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.
The digest of a Blob is only available after it has been saved to a Database. If a Blob is part of a Document, it is automatically saved when that document is being saved. Alternatively, a Blob can also be saved explicitly, with Database.saveBlob.
Constructors
- Blob.fromData(String contentType, Uint8List data)
-
Creates a Blob with the given in-memory data.
factory
-
Blob.fromStream(String contentType, Stream<
Uint8List> stream) -
Creates a Blob from a
streamof chunks of data.factory
Properties
- contentType → String?
-
The type of content this Blob represents.
no setter
- digest → String?
-
The cryptographic digest of this Blob’s content, which uniquely
identifies it.
no setter
- hashCode → int
-
The hash code for this object.
no setterinherited
- length → int?
-
The binary length of this Blob.
no setter
-
properties
→ Map<
String, Object?> -
The metadata representation of this Blob.
no setter
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
content(
) → Future< Uint8List> - Gets the contents of this Blob as a block of memory.
-
contentStream(
) → Stream< Uint8List> - A stream of the content of this Blob.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toJson(
) → String - Returns this blob's JSON representation.
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited