W3cubDocs

/Web APIs

Metadata: modificationTime property

Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The read-only modificationTime property of the Metadata interface is a Date object which specifies the date and time the file system entry (or the data referenced by the entry) was last modified. A file system entry is considered to have been modified if the metadata or the contents of the referenced file (or directory, or whatever other kind of file system entry might exist on the platform in use) has changed.

Value

A Date timestamp indicating when the file system entry was last changed.

Examples

This example tries to get a particular working file at tmp/workfile.json. Once that file has been found, its metadata is obtained and the file's modification timestamp year is compared to the current year. If it was last modified in a year at least five prior to the current year, the file is removed and a new one is created.

js

workingDirectory.getFile(
  "tmp/workfile.json",
  { create: true },
  (fileEntry) => {
    fileEntry.getMetadata((metadata) => {
      if (
        new Date().getFullYear() - metadata.modificationTime.getFullYear() >=
        5
      ) {
        fileEntry.remove(() => {
          workingDirectory.getFile(
            "tmp/workfile.json",
            { create: true },
            (newEntry) => {
              fileEntry = newEntry;
            },
          );
        });
      }
    });
  },
  handleError,
);

Specifications

This feature has been removed from all specification and is not in the process of being standardized.

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
modificationTime 13 79 No No No No No 18 No No No 1.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Metadata/modificationTime