web api instance method

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

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.

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

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.