Add function to build canonical url

gallery/utils.py

@@ -0,0 +1,31 @@
+from urllib.parse import urlencode, urlparse, urlunparse
+
+from django.conf import settings
+from django.urls import reverse
+
+
+def build_canonical_url(request, base_url=None, params=None):
+
+    if base_url is None:
+        base_url = request.path
+    elif base_url.startswith('/'):
+        base_url = base_url
+    else:
+        parsed = urlparse(base_url)
+        base_url = parsed.path + ('?' + parsed.query if parsed.query else '')
+
+    filtered_params = {
+        k: v for k, v in (params or {}).items()
+        if v not in (None, '', [], {}) and not (k == 'page' and str(v) == '1')
+    }
+
+    query_string = urlencode(filtered_params)
+    path = base_url
+    if query_string:
+        path += '?' + query_string
+
+    domain = getattr(settings, 'CANONICAL_URL_DOMAIN', None)
+    if domain:
+        return domain.rstrip('/') + path
+
+    return request.build_absolute_uri(path)