(JavaScript) Get the Last-Modified Date Before HTTP Download

Demonstrates how to send a HEAD request to get the last-modified date of a file on a web server (without downloading the file).

Note: This example requires Chilkat v11.0.0 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

var http = new CkHttp();

var resp = new CkHttpResponse();
success = http.HttpNoBody("HEAD","https://www.chilkatsoft.com/hamlet.xml",resp);
if (success == false) {
    console.log(http.LastErrorText);
    return;
}

// Examine the response header.
console.log(resp.Header);

// Here is a sample response header:

// 	Content-Length: 279658
// 	Content-Type: text/xml
// 	Last-Modified: Thu, 12 May 2016 15:14:08 GMT
// 	Accept-Ranges: bytes
// 	ETag: "c1cd8bee60acd11:0"
// 	Server: Microsoft-IIS/8.5
// 	X-Powered-By: ASP.NET
// 	X-Powered-By-Plesk: PleskWin
// 	Date: Thu, 25 Jul 2019 16:40:54 GMT

// Get the Last-Modified header.
var lastModStr = resp.GetHeaderField("Last-Modified");
// If the header exists...
if (resp.LastMethodSuccess == true) {
    // Parse the RFC822 format date/time string
    var ckdt = new CkDateTime();
    ckdt.SetFromRfc822(lastModStr);

    // If we want to access individual date/time parts (in the local timezone)
    var dt = new CkDtObj();
    ckdt.ToDtObj(true,dt);

    console.log("day/month/year = " + dt.Day + "/" + dt.Month + "/" + dt.Year);
}