#2502 - Add jinja2 template handling to request body and headers (#2740)

.gitignore

@@ -10,5 +10,6 @@ dist
 venv
 test-datastore/*
 test-datastore
+test-memory.log
 *.egg-info*
 .vscode/settings.json

changedetectionio/forms.py

@@ -515,6 +515,7 @@ class processor_text_json_diff_form(commonSettingsForm):
         if not super().validate():
             return False
 
+        from changedetectionio.safe_jinja import render as jinja_render
         result = True
 
         # Fail form validation when a body is set for a GET
@@ -524,16 +525,44 @@ class processor_text_json_diff_form(commonSettingsForm):
 
         # Attempt to validate jinja2 templates in the URL
         try:
-            from changedetectionio.safe_jinja import render as jinja_render
             jinja_render(template_str=self.url.data)
         except ModuleNotFoundError as e:
             # incase jinja2_time or others is missing
             logger.error(e)
-            self.url.errors.append(e)
+            self.url.errors.append(f'Invalid template syntax configuration: {e}')
+            result = False
+        except Exception as e:
+            logger.error(e)
+            self.url.errors.append(f'Invalid template syntax: {e}')
+            result = False
+
+        # Attempt to validate jinja2 templates in the body
+        if self.body.data and self.body.data.strip():
+            try:
+                jinja_render(template_str=self.body.data)
+            except ModuleNotFoundError as e:
+                # incase jinja2_time or others is missing
+                logger.error(e)
+                self.body.errors.append(f'Invalid template syntax configuration: {e}')
+                result = False
+            except Exception as e:
+                logger.error(e)
+                self.body.errors.append(f'Invalid template syntax: {e}')
+                result = False
+
+        # Attempt to validate jinja2 templates in the headers
+        if len(self.headers.data) > 0:
+            try:
+                for header, value in self.headers.data.items():
+                    jinja_render(template_str=value)
+            except ModuleNotFoundError as e:
+                # incase jinja2_time or others is missing
+                logger.error(e)
+                self.headers.errors.append(f'Invalid template syntax configuration: {e}')
                 result = False
             except Exception as e:
                 logger.error(e)
-            self.url.errors.append('Invalid template syntax')
+                self.headers.errors.append(f'Invalid template syntax in "{header}" header: {e}')
                 result = False
 
         return result

changedetectionio/processors/__init__.py

@@ -102,6 +102,7 @@ class difference_detection_processor():
             self.fetcher.browser_steps_screenshot_path = os.path.join(self.datastore.datastore_path, self.watch.get('uuid'))
 
         # Tweak the base config with the per-watch ones
+        from changedetectionio.safe_jinja import render as jinja_render
         request_headers = CaseInsensitiveDict()
 
         ua = self.datastore.data['settings']['requests'].get('default_ua')
@@ -118,9 +119,15 @@ class difference_detection_processor():
         if 'Accept-Encoding' in request_headers and "br" in request_headers['Accept-Encoding']:
             request_headers['Accept-Encoding'] = request_headers['Accept-Encoding'].replace(', br', '')
 
+        for header_name in request_headers:
+            request_headers.update({header_name: jinja_render(template_str=request_headers.get(header_name))})
+
         timeout = self.datastore.data['settings']['requests'].get('timeout')
 
         request_body = self.watch.get('body')
+        if request_body:
+            request_body = jinja_render(template_str=self.watch.get('body'))
+        
         request_method = self.watch.get('method')
         ignore_status_codes = self.watch.get('ignore_status_codes', False)
 

changedetectionio/templates/edit.html

@@ -65,8 +65,8 @@
                 <fieldset>
                     <div class="pure-control-group">
                         {{ render_field(form.url, placeholder="https://...", required=true, class="m-d") }}
-                        <span class="pure-form-message-inline">Some sites use JavaScript to create the content, for this you should <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">use the Chrome/WebDriver Fetcher</a></span><br>
-                        <span class="pure-form-message-inline">You can use variables in the URL, perfect for inserting the current date and other logic, <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a></span><br>
+                        <div class="pure-form-message">Some sites use JavaScript to create the content, for this you should <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">use the Chrome/WebDriver Fetcher</a></div>
+                        <div class="pure-form-message">Variables are supported in the URL (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
                     </div>
                     <div class="pure-control-group inline-radio">
                         {{ render_field(form.processor) }}
@@ -149,21 +149,24 @@
                             {{ render_field(form.method) }}
                         </div>
                         <div id="request-body">
-                                            {{ render_field(form.body, rows=5, placeholder="Example
+                                            {{ render_field(form.body, rows=7, placeholder="Example
 {
    \"name\":\"John\",
    \"age\":30,
-   \"car\":null
+   \"car\":null,
+   \"year\":{% now 'Europe/Berlin', '%Y' %}
 }") }}
                         </div>
+                        <div class="pure-form-message">Variables are supported in the request body (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
                     </div>
                 </fieldset>
             <!-- hmm -->
                 <div class="pure-control-group advanced-options"  style="display: none;">
-                    {{ render_field(form.headers, rows=5, placeholder="Example
+                    {{ render_field(form.headers, rows=7, placeholder="Example
 Cookie: foobar
-User-Agent: wonderbra 1.0") }}
-
+User-Agent: wonderbra 1.0
+Math: {{ 1 + 1 }}") }}
+                        <div class="pure-form-message">Variables are supported in the request header values (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
                         <div class="pure-form-message-inline">
                             {% if has_extra_headers_file %}
                                 <strong>Alert! Extra headers file found and will be added to this watch!</strong>

changedetectionio/tests/test_request.py

@@ -45,7 +45,7 @@ def test_headers_in_request(client, live_server, measure_memory_usage):
               "url": test_url,
               "tags": "",
               "fetch_backend": 'html_webdriver' if os.getenv('PLAYWRIGHT_DRIVER_URL') else 'html_requests',
-              "headers": "xxx:ooo\ncool:yeah\r\ncookie:"+cookie_header},
+              "headers": "jinja2:{{ 1+1 }}\nxxx:ooo\ncool:yeah\r\ncookie:"+cookie_header},
         follow_redirects=True
     )
     assert b"Updated watch." in res.data
@@ -61,6 +61,7 @@ def test_headers_in_request(client, live_server, measure_memory_usage):
     )
 
     # Flask will convert the header key to uppercase
+    assert b"Jinja2:2" in res.data
     assert b"Xxx:ooo" in res.data
     assert b"Cool:yeah" in res.data
 
@@ -117,7 +118,8 @@ def test_body_in_request(client, live_server, measure_memory_usage):
     wait_for_all_checks(client)
 
     # Now the change which should trigger a change
-    body_value = 'Test Body Value'
+    body_value = 'Test Body Value {{ 1+1 }}'
+    body_value_formatted = 'Test Body Value 2'
     res = client.post(
         url_for("edit_page", uuid="first"),
         data={
@@ -140,8 +142,9 @@ def test_body_in_request(client, live_server, measure_memory_usage):
 
     # If this gets stuck something is wrong, something should always be there
     assert b"No history found" not in res.data
-    # We should see what we sent in the reply
-    assert str.encode(body_value) in res.data
+    # We should see the formatted value of what we sent in the reply
+    assert str.encode(body_value) not in res.data
+    assert str.encode(body_value_formatted) in res.data
 
     ####### data sanity checks
     # Add the test URL twice, we will check