web: Improve error page

Add some useful links, including a link to a pre-filled bug report form

elixir/web.py

@@ -23,6 +23,7 @@ import os
 import sys
 import threading
 import time
+import datetime
 from collections import OrderedDict, namedtuple
 from re import search, sub
 from urllib import parse
@@ -39,6 +40,7 @@ from .query import get_query
 from .web_utils import ProjectConverter, IdentConverter, validate_version, validate_project, validate_ident
 
 VERSION_CACHE_DURATION_SECONDS = 2 * 60  # 2 minutes
+ADD_ISSUE_LINK = "https://github.com/bootlin/elixir/issues/new"
 
 # Error with extra information about browsed project,
 # to be used in project/version URLs
@@ -51,8 +53,28 @@ class ElixirProjectError(falcon.errors.HTTPError):
         self.extra_template_args = extra_template_args
         super().__init__(status, title=title, description=description, **kwargs)
 
+# Generate a summary of error details for a bug report
+def generate_error_details(req, resp, title, details):
+    return f"Request date: {datetime.datetime.now()}\n" + \
+           f"Path: {req.path}\n" + \
+           f"Query string: {req.query_string}\n" + \
+           f"Method: {req.method}\n" + \
+           f"Status code: {resp.status}\n" + \
+           f"Error title: {title}\n" + \
+           f"Error details: {details}\n"
+
+def get_github_issue_link(details: str):
+    body = "TODO: add information on how you reached the error here. Please make sure details below are correct and what you want to share.\n" + \
+           "---\n" + \
+           details
+
+    return ADD_ISSUE_LINK + "?body=" + parse.quote(body)
+
+
 # Generate an error page from ElixirProjectError
 def get_project_error_page(req, resp, exception: ElixirProjectError):
+    report_error_details = generate_error_details(req, resp, exception.title, exception.description)
+
     template_ctx = {
         'projects': get_projects(req.context.config.project_dir),
         'topbar_families': TOPBAR_FAMILIES,
@@ -60,7 +82,8 @@ def get_project_error_page(req, resp, exception: ElixirProjectError):
         'current_family': 'A',
         'source_base_url': '/',
 
-        'referer': req.referer,
+        'referer': req.referer if req.referer != req.uri else None,
+        'bug_report_link': get_github_issue_link(report_error_details),
 
         'error_title': exception.title,
     }
@@ -112,7 +135,9 @@ def get_project_error_page(req, resp, exception: ElixirProjectError):
     return result
 
 # Generate an error page from falcon exceptions
-def get_error_page(req, exception: ElixirProjectError):
+def get_error_page(req, resp, exception: ElixirProjectError):
+    report_error_details = generate_error_details(req, resp, exception.title, exception.description)
+
     template_ctx = {
         'projects': get_projects(req.context.config.project_dir),
         'topbar_families': TOPBAR_FAMILIES,
@@ -121,6 +146,7 @@ def get_error_page(req, exception: ElixirProjectError):
         'source_base_url': '/',
 
         'referer': req.referer,
+        'bug_report_link': ADD_ISSUE_LINK + parse.quote(report_error_details),
 
         'error_title': exception.title,
     }
@@ -711,7 +737,7 @@ def error_serializer(req, resp, exception):
             if isinstance(exception, ElixirProjectError):
                 resp.text = get_project_error_page(req, resp, exception)
             else:
-                resp.text = get_error_page(req, exception)
+                resp.text = get_error_page(req, resp, exception)
             resp.content_type = falcon.MEDIA_HTML
 
     resp.append_header('Vary', 'Accept')

static/style.css

@@ -102,6 +102,11 @@ h2 {
   margin-bottom: 1rem;
 }
 
+.link {
+  color: #6d7dd2;
+  text-decoration: underline;
+}
+
 
 /* oocss */
 
@@ -648,6 +653,21 @@ h2 {
   padding: 1.5em;
 }
 
+#error-details {
+  margin-bottom: 1em;
+}
+
+#error-details-links * {
+  display: block;
+}
+
+#error-details-links button {
+  border: 0;
+  background-color: transparent;
+  padding: 0;
+  margin: 0;
+}
+
 
 /* ident */
 

templates/error.html

@@ -8,7 +8,19 @@
 
 <div class="lxrerror">
     <h2>{{ error_title }}</h2>
-    {{ error_details|default('') }}
+    <div id="error-details">
+        {{ error_details|default('') }}
+    </div>
+    <span>You might want to:</span>
+    <ul>
+        {% if referer is not none -%}
+            <li><a class="link" href="{{ referer }}">Go back</a></li>
+        {%- endif %}
+        <li><a class="link" href="/">Go to home page</a></li>
+        {% if bug_report_link is not none -%}
+            <li><a class="link" href="{{ bug_report_link }}">Report a bug</a></li>
+        {%- endif %}
+    </ul>
 </div>
 
 {% endblock %}

templates/layout.html

@@ -15,7 +15,7 @@
             Elixir Cross Referencer - Explore source code in your browser - Particularly useful for the Linux kernel and other low-level projects in C/C++ (bootloaders, C libraries...)
             {%- endblock %}">
         <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1" />
-        <link rel="stylesheet" href="/static/style.css?v=10">
+        <link rel="stylesheet" href="/static/style.css?v=11">
         <link rel="stylesheet" href="/static/banner.css">
         <link rel="stylesheet" href="/static/autocomplete.css?v=2">
         <script>