etag

1 files changed, 8 insertions, 1 deletions

diff --git a/talerblog/blog/blog.py b/talerblog/blog/blog.py
index 5340d56..47b7074 100644
--- a/talerblog/blog/blog.py
+++ b/talerblog/blog/blog.py
@@ -328,13 +328,20 @@ def article(article_name, data=None):
         # Redirect the browser to a page where the wallet can
         # run the payment protocol.
         contract_url = pay_status["contract_url"]
+        taler_pay_uri = "talerpay:" + urllib.parse.quote_plus(contract_url) + ";" + session_id
+        req_etag = request.headers.get("If-None-Match")
+        resp_etag = f"\"{taler_pay_uri}\""
+        if req_etag == resp_etag:
+            resp = flask.Response(status=304)
+            return resp
+
         headers = {
                 "Taler-Contract-Url": urllib.parse.quote(contract_url),
                 "Taler-Session-Url": urllib.parse.quote(session_id),
                 "Taler-Resource-Url": urllib.parse.quote(resource_url),
+                "ETag": resp_etag,
         }
 
-        taler_pay_uri = "talerpay:" + urllib.parse.quote_plus(contract_url) + ";" + session_id
         qrcode_svg = get_qrcode_svg(taler_pay_uri)
         content = flask.render_template("templates/request_payment.html",
                                          article_name=article_name,