FileReader: readyState property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.
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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
FileorBlobis being read, and no error has occurred yet. FileReader.DONE(2)-
The read operation is complete. This could mean that: the entire
FileorBlobhas been read into memory, a file read error occurred, orabort()was called and the read was cancelled.
Examples
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 |