[enh] wolframalpha appends result

searx/engines/wolframalpha_api.py

 # search-url
 base_url = 'http://api.wolframalpha.com/v2/query'
 search_url = base_url + '?appid={api_key}&{query}&format=plaintext'
+site_url = 'http://www.wolframalpha.com/input/?{query}'
+search_query = ''
 api_key = ''
 
+# xpath variables
+failure_xpath = '/queryresult[attribute::success="false"]'
+answer_xpath = '//pod[attribute::primary="true"]/subpod/plaintext'
+
 
 # do search-request
 def request(query, params):
     params['url'] = search_url.format(query=urlencode({'input': query}),
                                       api_key=api_key)
 
+    # used in response
+    global search_query
+    search_query = query
+
     return params
 
 
     search_results = etree.XML(resp.content)
 
     # return empty array if there are no results
-    if search_results.xpath('/queryresult[attribute::success="false"]'):
+    if search_results.xpath(failure_xpath):
         return []
 
     # parse answer
-    answer = search_results.xpath('//pod[attribute::primary="true"]/subpod/plaintext')
-    if not answer:
-        return results
+    answer = search_results.xpath(answer_xpath)
+    if answer:
+        answer = replace_pua_chars(answer[0].text)
+
+        results.append({'answer': answer})
 
-    answer = replace_pua_chars(answer[0].text)
+    # result url
+    result_url = site_url.format(query=urlencode({'i': search_query}))
 
     # append result
-    # TODO: shouldn't it bind the source too?
-    results.append({'answer': answer})
+    results.append({'url': result_url,
+                    'title': search_query + ' - Wolfram|Alpha'})
 
-    # return results
     return results

searx/engines/wolframalpha_noapi.py

 # WolframAlpha (Maths)
 #
 # @website     http://www.wolframalpha.com/
+# @provide-api yes (http://api.wolframalpha.com/v2/)
 #
 # @using-api   no
 # @results     HTML
 # search-url
 url = 'http://www.wolframalpha.com/'
 search_url = url+'input/?{query}'
+search_query = ''
 
 
 # do search-request
 def request(query, params):
     params['url'] = search_url.format(query=urlencode({'i': query}))
 
+    # used in response
+    global search_query
+    search_query = query
+
     return params
 
 
         except AttributeError:
             continue
 
-    if not line:
-        return results
+    if line:
+        # extract answer from json
+        answer = line[line.find('{'):line.rfind('}')+1]
+        answer = loads(answer.encode('unicode-escape'))
+        answer = answer['stringified'].decode('unicode-escape')
+        
+        results.append({'answer': answer})
 
-    # extract answer from json
-    answer = line[line.find('{'):line.rfind('}')+1]
-    answer = loads(answer.encode('unicode-escape'))
-    answer = answer['stringified'].decode('unicode-escape')
+    # failed result
+    elif search('pfail', webpage):
+        return results
 
-    results.append({'answer': answer})
+    # append result
+    results.append({'url': request(search_query, {})['url'],
+                    'title': search_query + ' - Wolfram|Alpha'})
 
     return results

searx/settings.yml

     engine : vimeo
     shortcut : vm
 
-# You can use the engine using the official stable API, but you need an API key
-# See : http://products.wolframalpha.com/api/
   - name : wolframalpha
     shortcut : wa
+    # You can use the engine using the official stable API, but you need an API key
+    # See : http://products.wolframalpha.com/api/
+    #    engine : wolframalpha_api
+    #    api_key: 'api_key' # required!
     engine : wolframalpha_noapi
-#    api_key: 'apikey' # required!
     timeout: 6.0
 
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