1 files changed, 21 insertions, 2 deletions
diff --git a/src/webclientserver.cpp b/src/webclientserver.cpp
index 44d120e..0e32717 100644
--- a/src/webclientserver.cpp
+++ b/src/webclientserver.cpp
@@ -72,7 +72,7 @@ void HttpRequest::parseText()
 }
 
 HttpResponse::HttpResponse()
-: contentType("text/html"), response304(false) { }
+: contentType("text/html"), response304(false), neverExpires(false) { }
 
 void HttpResponse::setBody(const QByteArray &body)
 {
@@ -99,6 +99,11 @@ void HttpResponse::set304Response()
     response304 = true;
 }
 
+void HttpResponse::setNeverExpires()
+{
+    neverExpires = true;
+}
+
 bool HttpResponse::isHandled() const
 {
     return response304 || body.isEmpty() == false;
@@ -125,7 +130,21 @@ QByteArray HttpResponse::toText()
         text+= "Set-Cookie: " + cookie + "\r\n";
     }
     
-    if (eTag.isEmpty() == false) {
+    // Support three different caching strategies:
+    // 1. Never-expires. Useful when content has a unique
+    // name based on e.g. a hash of the content. Allows the
+    // user agent to get the content once and then cache it
+    // forever.
+    // 2. Etag. The url for the content stays the same, the
+    // etag changes with content changes. Allows the user agent
+    // to ask if a spesific url as been updated, and then skip
+    // the content download if not.
+    // 3. no-cache. For dynamic content. Not cached by the user-agent
+    // and is re-downloaded on each request.
+    if (neverExpires) {
+        text += QByteArray("Cache-control: max-age: 99999 \r\n"); // or -1?
+        text += "eTag: 24 \r\n";
+    } else if (eTag.isEmpty() == false) {
         text += "eTag: " + eTag + "\r\n";
     } else {
         text += QByteArray("Cace-control: no-cache \r\n");