FileSystemDirectoryEntry: createReader() method

The FileSystemDirectoryEntry interface's method createReader() returns a FileSystemDirectoryReader object which can be used to read the entries in the directory.

Syntax

js
createReader()

Parameters

None.

Return value

A FileSystemDirectoryReader object which can be used to read the directory's entries.

Examples

This example creates an async function called readDirectory(), which fetches all of the entries in the specified FileSystemDirectoryEntry and returns them in an array.

js
async function readDirectory(directory) {
  const dirReader = directory.createReader();
  const entries = [];

  while (true) {
    const results = await new Promise((resolve, reject) => {
      dirReader.readEntries(resolve, reject);
    });

    if (!results.length) {
      break;
    }

    for (const entry of results) {
      entries.push(entry);
    }
  }

  return entries;
}

This works by calling readEntries() repetitively to get all the entries in the directory, concatenating each batch to the array. When it returns an empty array, all entries have been read, and the loop ends.

Specifications

Specification
File and Directory Entries API
# dom-filesystemdirectoryentry-createreader

Browser compatibility

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Chrome
Edge
Firefox
Opera
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Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
createReader

Legend

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Full support
Full support
No support
No support

See also