Add ability to set temp config in search query

Dark mode, country, interface language, and search language configs
can now be set in the search query by appending each option as a
url parameter.

Supported args are: 'dark', 'lang_search', 'lang_interface', and 'ctry'

Ex: /search?q=%s&dark=1&lang_search=lang_en...

These config settings persist across page navigation and switching
result type, but will be reset if the main search bar is used.

See #144

app/filter.py

@@ -53,7 +53,6 @@ class Filter:
         self.fix_question_section()
         self.update_styling(soup)
 
-
         for img in [_ for _ in soup.find_all('img') if 'src' in _.attrs]:
             self.update_element_src(img, 'image/png')
 

app/models/config.py

@@ -325,3 +325,39 @@ class Config:
 
     def __contains__(self, name):
         return hasattr(self, name)
+
+    def is_safe_key(self, key) -> bool:
+        """Establishes a group of config options that are safe to set
+        in the url.
+
+        Args:
+            key (str) -- the key to check against
+
+        Returns:
+            bool -- True/False depending on if the key is in the "safe"
+            array
+        """
+
+        return key in [
+            'lang_search',
+            'lang_interface',
+            'ctry',
+            'dark'
+        ]
+
+    def from_params(self, params) -> 'Config':
+        """Modify user config with search parameters. This is primarily
+        used for specifying configuration on a search-by-search basis on
+        public instances.
+
+        Args:
+            params -- the url arguments (can be any deemed safe by is_safe())
+
+        Returns:
+            Config -- a modified config object
+        """
+        for param_key in params.keys():
+            if not self.is_safe_key(param_key):
+                continue
+            self[param_key] = params.get(param_key)
+        return self

app/routes.py

@@ -161,6 +161,9 @@ def search():
     # Reset element counter
     app.user_elements[session['uuid']] = 0
 
+    # Update user config if specified in search args
+    g.user_config = g.user_config.from_params(g.request_params)
+
     search_util = RoutingUtils(request, g.user_config, session, cookies_disabled=g.cookies_disabled)
     query = search_util.new_search_query()
 

app/templates/header.html

@@ -3,7 +3,7 @@
         <div class="bz1lBb">
             <form class="Pg70bf" id="search-form" method="POST">
                 <a class="logo-link mobile-logo"
-                   href=""
+                   href="/"
                    style="display:flex; justify-content:center; align-items:center; color:#685e79; font-size:18px; ">
                     <span style="color: #685e79">Whoogle</span>
                 </a>
@@ -24,7 +24,7 @@
 {% else %}
     <header>
         <div class="logo-div">
-            <a class="logo-link" href="">
+            <a class="logo-link" href="/">
                 <span style="color: #685e79">Whoogle</span>
             </a>
         </div>

app/utils/routing_utils.py

@@ -81,4 +81,14 @@ class RoutingUtils:
             return get_first_link(html_soup), 1
         else:
             formatted_results = content_filter.clean(html_soup)
+
+            # Append user config to all search links, if available
+            param_str = ''.join('&{}={}'.format(k, v) 
+                    for k, v in self.request_params.to_dict(flat=True).items()
+                    if self.config.is_safe_key(k))
+            for link in formatted_results.find_all('a', href=True):
+                if 'search?' not in link['href'] or link['href'].index('search?') > 1:
+                    continue
+                link['href'] += param_str
+
             return formatted_results, content_filter.elements

test/test_routes.py

@@ -48,6 +48,12 @@ def test_config(client):
     for key in demo_config.keys():
         assert config[key] == demo_config[key]
 
+    # Test setting config via search
+    custom_config = '&dark=1&lang_interface=lang_en'
+    rv = client.get('/search?q=test' + custom_config)
+    assert rv._status_code == 200
+    assert custom_config.replace('&', '&') in str(rv.data)
+
 
 def test_opensearch(client):
     rv = client.get('/opensearch.xml')