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FileReaderSync: readAsText() method - Web APIs | MDN
FileReaderSync: readAsText() method Baseline Widely available
The readAsText()
method of the FileReaderSync
interface allows to read File
or Blob
objects in a synchronous way into a string. This interface is only available in workers as it enables synchronous I/O that could potentially block.
readAsText(blob)
readAsText(blob, encoding)
blob
The File
or Blob
to read.
encoding
Optional
The optional parameter specifies encoding to be used (e.g., iso-8859-1
or UTF-8
). If not present, the method will apply a detection algorithm for it.
A string representing the input data.
The following exceptions can be raised by this method:
NotFoundError
DOMException
Thrown if the resource represented by the DOM File
or Blob
cannot be found, e.g., because it has been erased.
SecurityError
DOMException
Thrown if one of the following problematic situation is detected:
the resource has been modified by a third party;
too many read are performed simultaneously;
the file pointed by the resource is unsafe for a use from the Web (like it is a system file).
NotReadableError
DOMException
Thrown if the resource cannot be read due to a permission problem, like a concurrent lock.
EncodingError
DOMException
Thrown if the resource is a data URL and exceed the limit length defined by each browser.