I have a set of links on a web page that link to PDF forms and .doc forms. These files are not stored in a database, simply stored as they are, locally on the server. Is it possible to retrieve the last modified date of a PDF or DOC file using Javascript? I don't have any specific need to use Javascript, but it is preferable.
UPDATE: Now that I realize that Javascript can't access the filesystem, is there an alternative method?
If it's on the same server as your calling function you can use XMLHttpRequest-
This example is not asynchronous, but you can make it so if you wish.
function fetchHeader(url, wch) {
try {
var req=new XMLHttpRequest();
req.open("HEAD", url, false);
req.send(null);
if(req.status== 200){
return req.getResponseHeader(wch);
}
else return false;
} catch(er) {
return er.message;
}
}
alert(fetchHeader(location.href,'Last-Modified'));
Using the modern fetch method:
var lastMod = null;
fetch(xmlPath).then(r => {
lastMod = r.headers.get('Last-Modified');
return r.text();
})
You can use the File.lastModified property to obtain the last modified date of a file as the number of milliseconds since the Unix epoch.
Example:
const file = document.getElementById('input').files[0];
const lastModifiedDate = new Date(file.lastModified);
console.log(`Last Modified Date: ${lastModifiedDate}`);
If an interface is exposed through HTTP, you can. Another way of saying: expose a WebService end-point to gain access to this information.
Of course, you can't have direct access to the filesystem for security reasons.