[#366] Context variables should be dynamically assigned through `locals()` instead of `exec()`.

Closes: #366

platypush/backend/http/request/__init__.py

@@ -1,7 +1,6 @@
 import logging
-import re
-from threading import Thread
 import time
+from threading import Thread
 
 import requests
 from frozendict import frozendict
@@ -91,7 +90,7 @@ class HttpRequest:
 
         Thread(target=_thread_func, name='HttpPoll').start()
 
-    def get_new_items(self, response):
+    def get_new_items(self, *_, **__):
         """Gets new items out of a response"""
         raise NotImplementedError(
             "get_new_items must be implemented in a derived class"
@@ -105,34 +104,6 @@ class HttpRequest:
             yield key, value
 
 
-class JsonHttpRequest(HttpRequest):
-    """
-    Specialization of the HttpRequest class for JSON requests.
-    """
-
-    def __init__(self, *args, path=None, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.path = path
-        self.seen_entries = set()
-
-    def get_new_items(self, response):
-        response = response.json()
-        new_entries = []
-
-        if self.path:
-            m = re.match(r'\${\s*(.*)\s*}', self.path)
-            if m:
-                response = eval(m.group(1))  # pylint: disable=eval-used
-
-        for entry in response:
-            flattened_entry = deep_freeze(entry)
-            if flattened_entry not in self.seen_entries:
-                new_entries.append(entry)
-            self.seen_entries.add(flattened_entry)
-
-        return new_entries
-
-
 def deep_freeze(x):
     """
     Deep freezes a Python object - works for strings, dictionaries, sets and

platypush/message/request/__init__.py

@@ -141,19 +141,8 @@ class Request(Message):
         for k, v in context.items():
             if isinstance(v, Message):
                 v = json.loads(str(v))
-            try:
-                exec('{}={}'.format(k, v))  # pylint: disable=exec-used
-            except Exception:
-                if isinstance(v, str):
-                    try:
-                        exec(  # pylint: disable=exec-used
-                            '{}="{}"'.format(k, re.sub(r'(^|[^\\])"', '\1\\"', v))
-                        )
-                    except Exception as e2:
-                        logger.debug(
-                            'Could not set context variable %s=%s: %s', k, v, e2
-                        )
-                        logger.debug('Context: %s', context)
+
+            locals()[k] = v
 
         parsed_value = ''
         if not isinstance(_value, str):

platypush/procedure/__init__.py

@@ -422,10 +422,7 @@ class WhileProcedure(LoopProcedure):
         response = Response()
         context = self._get_context(**context)
         for k, v in context.items():
-            try:
-                exec(f'{k}={v}')  # pylint: disable=exec-used
-            except Exception as e:
-                logger.debug('Evaluation error: %s=%s: %s', k, v, e)
+            locals()[k] = v
 
         while True:
             condition_true = eval(self.condition)  # pylint: disable=eval-used
@@ -451,10 +448,7 @@ class WhileProcedure(LoopProcedure):
             if response.output and isinstance(response.output, dict):
                 new_context = self._get_context(**response.output)
                 for k, v in new_context.items():
-                    try:
-                        exec(f'{k}={v}')  # pylint: disable=exec-used
-                    except Exception as e:
-                        logger.debug('Evaluation error: %s=%s: %s', k, v, e)
+                    locals()[k] = v
 
         return response
 
@@ -550,19 +544,7 @@ class IfProcedure(Procedure):
 
     def execute(self, *_, **context):
         for k, v in context.items():
-            try:
-                exec(f'{k}={v}')  # pylint: disable=exec-used
-            except Exception:
-                if isinstance(v, str):
-                    try:
-                        exec(  # pylint: disable=exec-used
-                            f'{k}="' + re.sub(r'(^|[^\\])"', '\1\\"', v) + '"'
-                        )
-                    except Exception as e:
-                        logger.debug(
-                            'Could not set context variable %s=%s: %s', k, v, e
-                        )
-                        logger.debug('Context: %s', context)
+            locals()[k] = v
 
         condition_true = eval(self.condition)  # pylint: disable=eval-used
         response = Response()