From 07a502f527693949cfdc33aa85ff261403bd013e Mon Sep 17 00:00:00 2001
From: dgtlmoon <dgtlmoon@gmail.com>
Date: Tue, 10 Mar 2026 11:15:44 +0100
Subject: [PATCH] UI - Fixing Preview "GO" version button #3963

---
 changedetectionio/blueprint/ui/preview.py             | 7 +++++--
 changedetectionio/blueprint/ui/templates/preview.html | 3 ++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/changedetectionio/blueprint/ui/preview.py b/changedetectionio/blueprint/ui/preview.py
index a11abd1d..e45d58e2 100644
--- a/changedetectionio/blueprint/ui/preview.py
+++ b/changedetectionio/blueprint/ui/preview.py
@@ -10,7 +10,8 @@ from changedetectionio import html_tools
 def construct_blueprint(datastore: ChangeDetectionStore):
     preview_blueprint = Blueprint('ui_preview', __name__, template_folder="../ui/templates")
 
-    @preview_blueprint.route("/preview/<uuid_str:uuid>", methods=['GET'])
+
+    @preview_blueprint.route("/preview/<uuid_str:uuid>", methods=['GET', 'POST'])
     @login_optionally_required
     def preview_page(uuid):
         """
@@ -74,7 +75,9 @@ def construct_blueprint(datastore: ChangeDetectionStore):
             flash(gettext("Preview unavailable - No fetch/check completed or triggers not reached"), "error")
         else:
             # So prepare the latest preview or not
-            preferred_version = request.args.get('version')
+            preferred_version = request.values.get('version') if request.method == 'POST' else request.args.get('version')
+
+
             versions = list(watch.history.keys())
             timestamp = versions[-1]
             if preferred_version and preferred_version in versions:
diff --git a/changedetectionio/blueprint/ui/templates/preview.html b/changedetectionio/blueprint/ui/templates/preview.html
index b0a56765..ea9a49b9 100644
--- a/changedetectionio/blueprint/ui/templates/preview.html
+++ b/changedetectionio/blueprint/ui/templates/preview.html
@@ -17,7 +17,7 @@
     <script src="{{ url_for('static_content', group='js', filename='tabs.js') }}" defer></script>
     {% if versions|length >= 2 %}
         <div id="diff-form" style="text-align: center;">
-            <form class="pure-form " action="" method="POST">
+            <form class="pure-form "  action="{{url_for('ui.ui_preview.preview_page', uuid=uuid)}}" method="POST">
                 <fieldset>
                     <label for="preview-version">{{ _('Select timestamp') }}</label> <select id="preview-version"
                                                                                  name="from_version"
@@ -28,6 +28,7 @@
                         </option>
                     {% endfor %}
                 </select>
+                    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
                     <button type="submit" class="pure-button pure-button-primary">{{ _('Go') }}</button>
 
                 </fieldset>