Serve task statement PDFs with Content-Disposition: inline

Author: prandla

cms/server/contest/handlers/__init__.py

@@ -69,7 +69,7 @@
     # Tasks
 
     (r"/tasks/(.*)/description", TaskDescriptionHandler),
-    (r"/tasks/(.*)/statements/(.*)", TaskStatementViewHandler),
+    (r"/tasks/(.*)/statements/([^/]*)(?:/.*)?", TaskStatementViewHandler),
     (r"/tasks/(.*)/attachments/(.*)", TaskAttachmentViewHandler),
 
     # Task submissions

cms/server/contest/handlers/task.py

@@ -85,11 +85,11 @@ def get(self, task_name: str, lang_code: str):
         self.sql_session.close()
 
         if len(lang_code) > 0:
-            filename = "%s (%s).pdf" % (task.name, lang_code)
+            filename = "%s.%s.pdf" % (task.name, lang_code)
         else:
             filename = "%s.pdf" % task.name
 
-        self.fetch(statement, "application/pdf", filename)
+        self.fetch(statement, "application/pdf", filename=filename, disposition="inline")
 
 
 class TaskAttachmentViewHandler(FileHandler):

cms/server/contest/templates/task_description.html

@@ -2,6 +2,13 @@
 
 {% set page = "task_description" %}
 
+{# This macro includes the filename as the last component as a hack for chrome
+   to display the correct page title (which it pulls from just the last
+   component of the URL). It's completely ignored by the server. #}
+{% macro statement_url(lang_code) -%}
+{{ contest_url("tasks", task.name, "statements", lang_code, task.name + "." + lang_code + ".pdf") }}
+{%- endmacro %}
+
 {% block core %}
 
 
@@ -25,7 +32,7 @@ <h2>{% trans %}Statement{% endtrans %}</h2>
 <div class="row statement one_statement">
     <div class="span9">
     {% for lang_code in task.statements %}
-        <a href="{{ contest_url("tasks", task.name, "statements", lang_code) }}" class="btn btn-large btn-success">{% trans %}Download task statement{% endtrans %}</a>
+        <a href="{{ statement_url(lang_code) }}" target="_blank" class="btn btn-large btn-success">{% trans %}Download task statement{% endtrans %}</a>
     {% endfor %}
     </div>
 </div>
@@ -39,7 +46,7 @@ <h2>{% trans %}Statement{% endtrans %}</h2>
         </p>
     {% for statement in task.statements.values()|sort(attribute="language") %}
         {% if statement.language in task.primary_statements %}
-        <a href="{{ contest_url("tasks", task.name, "statements", statement.language) }}" class="btn btn-large btn-success">
+        <a href="{{ statement_url(statement.language) }}" target="_blank" class="btn btn-large btn-success">
             {% set language_name = statement.language|format_locale %}
             {% if statement.language != language_name %}
                 {% trans lang=language_name %}Statement in <b>{{ lang }}</b>{% endtrans %}
@@ -51,7 +58,7 @@ <h2>{% trans %}Statement{% endtrans %}</h2>
     {% endfor %}
     {% for statement in task.statements.values()|sort(attribute="language") %}
         {% if statement.language in participation.user.preferred_languages and statement.language not in task.primary_statements %}
-        <a href="{{ contest_url("tasks", task.name, "statements", statement.language) }}" class="btn btn-large">
+        <a href="{{ statement_url(statement.language) }}" target="_blank" class="btn btn-large">
             {% set language_name = statement.language|format_locale %}
             {% if statement.language != language_name %}
                 {% trans lang=language_name %}Statement in <b>{{ lang }}</b>{% endtrans %}
@@ -67,7 +74,7 @@ <h2>{% trans %}Statement{% endtrans %}</h2>
             <ul>
     {% for statement in task.statements.values()|sort(attribute="language") %}
                 <li>
-                    <a href="{{ contest_url("tasks", task.name, "statements", statement.language) }}">
+                    <a href="{{ statement_url(statement.language) }}" target="_blank">
         {% set language_name = statement.language|format_locale %}
         {% if statement.language != language_name %}
             {% trans lang=language_name %}<b>{{ lang }}</b>{% endtrans %}

cms/server/file_middleware.py

@@ -46,6 +46,7 @@ class FileServerMiddleware:
 
     DIGEST_HEADER = "X-CMS-File-Digest"
     FILENAME_HEADER = "X-CMS-File-Filename"
+    DISPOSITION_HEADER = "X-CMS-File-Disposition"
 
     def __init__(self, file_cacher: FileCacher, app: Callable):
         """Create an instance.
@@ -84,6 +85,7 @@ def wsgi_app(self, environ, start_response):
 
         digest = original_response.headers.pop(self.DIGEST_HEADER)
         filename = original_response.headers.pop(self.FILENAME_HEADER, None)
+        disposition = original_response.headers.pop(self.DISPOSITION_HEADER, "attachment")
         mimetype = original_response.mimetype
 
         try:
@@ -102,7 +104,7 @@ def wsgi_app(self, environ, start_response):
         response.mimetype = mimetype
         if filename is not None:
             response.headers.add(
-                "Content-Disposition", "attachment", filename=filename)
+                "Content-Disposition", disposition, filename=filename)
         response.set_etag(digest)
         response.cache_control.no_cache = True
         response.cache_control.private = True

cms/server/util.py

@@ -81,7 +81,7 @@ class FileHandlerMixin(RequestHandler):
 
     """
 
-    def fetch(self, digest: str, content_type: str, filename: str):
+    def fetch(self, digest: str, content_type: str, filename: str | None = None, disposition: str | None = None):
         """Serve the file with the given digest.
 
         This will just add the headers required to trigger
@@ -90,10 +90,14 @@ def fetch(self, digest: str, content_type: str, filename: str):
         digest: the digest of the file that has to be served.
         content_type: the MIME type the file should be served as.
         filename: the name the file should be served as.
+        disposition: value to set the Content-Disposition header to.
 
         """
         self.set_header(FileServerMiddleware.DIGEST_HEADER, digest)
-        self.set_header(FileServerMiddleware.FILENAME_HEADER, filename)
+        if filename is not None:
+            self.set_header(FileServerMiddleware.FILENAME_HEADER, filename)
+        if disposition is not None:
+            self.set_header(FileServerMiddleware.DISPOSITION_HEADER, disposition)
         self.set_header("Content-Type", content_type)
         self.finish()