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 a method called readDirectory()
, which fetches all of
the entries in the specified FileSystemDirectoryEntry
and returns them in
an array.
js
function readDirectory(directory) {
let dirReader = directory.createReader();
let entries = [];
let getEntries = () => {
dirReader.readEntries(
(results) => {
if (results.length) {
entries = entries.concat(toArray(results));
getEntries();
}
},
(error) => {
/* handle error — error is a FileError object */
}
);
};
getEntries();
return entries;
}
This works by creating an internal function, getEntries()
, which calls
itself recursively to get all the entries in the directory, concatenating each batch to
the array. Each iteration, readEntries()
is called to get more entries. When it returns an empty array, the
end of the directory has been reached, and the recursion ends. Once control is returned
to readDirectory()
, the array is returned to the caller.
Specifications
Specification |
---|
File and Directory Entries API # dom-filesystemdirectoryentry-createreader |
Browser compatibility
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