FileReader: readyState property
Note: This feature is available in Web Workers.
The readyState
read-only property of the FileReader
interface provides the current state of the reading operation.
This will be one of the states: EMPTY
, LOADING
, or DONE
.
Value
A number which is one of the three possible state constants defined on the FileReader
interface:
FileReader.EMPTY
(0)-
Reader has been created, but none of the read methods have been called yet.
FileReader.LOADING
(1)-
A read method has been called. A
File
orBlob
is being read, and no error has occurred yet. FileReader.DONE
(2)-
The read operation is complete. This could mean that: the entire
File
orBlob
has been read into memory, a file read error occurred, orabort()
was called and the read was cancelled.
Examples
js
const reader = new FileReader();
console.log("EMPTY", reader.readyState); // readyState will be 0
reader.readAsText(blob);
console.log("LOADING", reader.readyState); // readyState will be 1
reader.onloadend = () => {
console.log("DONE", reader.readyState); // readyState will be 2
};
Specifications
Specification |
---|
File API # dom-filereader-readystate |
Browser compatibility
BCD tables only load in the browser