Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The BlobBuilder
interface provides an easy way to construct Blob
objects. Just create a BlobBuilder
and append chunks of data to it by calling the append()
method. When you're done building your blob, call getBlob()
to retrieve a Blob
containing the data you sent into the blob builder.
BlobBuilder
interface has been deprecated in favor of the newly introduced Blob
constructor.Method overview
void append(in ArrayBuffer data); |
void append(in Blob data); |
void append(in String data, [optional] in String endings); |
Blob getBlob([optional] in DOMString contentType); |
File getFile(in DOMString name, [optional] in DOMString contentType); |
Methods
append()
Appends the contents of the specified JavaScript object to the Blob
being built. If the value you specify isn't a Blob
, ArrayBuffer
, or String
, the value is coerced to a string before being appended to the blob.
void append( in ArrayBuffer data ); void append( in Blob data ); void append( in String data, [optional] in String endings );
Parameters
data
- The data to append to the
Blob
being constructed. endings
- Specifies how strings containing
\n
are to be written out. This can be"transparent"
(endings unchanged) or"native"
(endings changed to match host OS filesystem convention). The default value is"transparent"
.
getBlob()
Returns the Blob
object that has been constructed using the data passed through calls to append()
.
Blob getBlob(
in DOMString contentType Optional
);
Parameters
- contentType Optional
- The MIME type of the data to be returned in the
Blob
. This will be the value of theBlob
object's type property.
Return value
A Blob
object containing all of the data passed to any calls to append()
made since the BlobBuilder
was created. This also resets the BlobBuilder
so that the next call to append()
is starting a new, empty blob.
getFile()
Returns a File
object.
File getFile( in DOMString name, [optional] in DOMString contentType );
Parameters
- name
- The file name.
- contentType Optional
- The MIME type of the data to be returned in the
File
. This will be the value of theFile
object's type property.
Return value
A File
object.
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 8[1] | Not supported[2] | 10[3] | Not supported | Not supported[1] |
getfile() |
Not supported | Not supported | Not supported | Not supported | Not supported |
Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | 3[1] | Not supported[2] | Not supported | Not supported | Not supported[1] |
getfile() |
Not supported | Not supported | Not supported | Not supported | Not supported |
[1] WebKit implemented the API as WebKitBlobBuilder
, though it has deprecated it now and has made its support configurable. Currently Safari disables the feature in Nightly, so it likely won't ship in a final version. On the other hand, Chrome, which has supported it since Chrome 8, still enables the feature. So Chrome might continue to support the feature. (See this WebKit changeset for details).
[2] Gecko implemented the API as MozBlobBuilder
. Starting in Firefox 14, using MozBlobBuilder
will show a warning message in the web console that the use of MozBlobBuilder
is deprecated and suggests to use Blob
constructor instead. In Gecko 18.0 this feature was removed.
[3] Trident implements the API as MSBlobBuilder
.