Plugins for conditions (and include Similarity / Levenshtein, wordcount conditions) Re #3108

changedetectionio/PLUGIN_README.md

@@ -0,0 +1,98 @@
+# Creating Plugins for changedetection.io
+
+This document describes how to create plugins for changedetection.io. Plugins can be used to extend the functionality of the application in various ways.
+
+## Plugin Types
+
+### UI Stats Tab Plugins
+
+These plugins can add content to the Stats tab in the Edit page. This is useful for adding custom statistics or visualizations about a watch.
+
+#### Creating a UI Stats Tab Plugin
+
+1. Create a Python file in a directory that will be loaded by the plugin system.
+
+2. Use the `global_hookimpl` decorator to implement the `ui_edit_stats_extras` hook:
+
+```python
+import pluggy
+from loguru import logger
+
+global_hookimpl = pluggy.HookimplMarker("changedetectionio")
+
+@global_hookimpl
+def ui_edit_stats_extras(watch):
+    """Add custom content to the stats tab"""
+    # Calculate or retrieve your stats
+    my_stat = calculate_something(watch)
+    
+    # Return HTML content as a string
+    html = f"""
+    <div class="my-plugin-stats">
+        <h4>My Plugin Statistics</h4>
+        <p>My statistic: {my_stat}</p>
+    </div>
+    """
+    return html
+```
+
+3. The HTML you return will be included in the Stats tab.
+
+## Plugin Loading
+
+Plugins can be loaded from:
+
+1. Built-in plugin directories in the codebase
+2. External packages using setuptools entry points
+
+To add a new plugin directory, modify the `plugin_dirs` dictionary in `pluggy_interface.py`.
+
+## Example Plugin
+
+Here's a simple example of a plugin that adds a word count statistic to the Stats tab:
+
+```python
+import pluggy
+from loguru import logger
+
+global_hookimpl = pluggy.HookimplMarker("changedetectionio")
+
+def count_words_in_history(watch):
+    """Count words in the latest snapshot"""
+    try:
+        if not watch.history.keys():
+            return 0
+            
+        latest_key = list(watch.history.keys())[-1]
+        latest_content = watch.get_history_snapshot(latest_key)
+        return len(latest_content.split())
+    except Exception as e:
+        logger.error(f"Error counting words: {str(e)}")
+        return 0
+
+@global_hookimpl
+def ui_edit_stats_extras(watch):
+    """Add word count to the Stats tab"""
+    word_count = count_words_in_history(watch)
+    
+    html = f"""
+    <div class="word-count-stats">
+        <h4>Content Analysis</h4>
+        <table class="pure-table">
+            <tbody>
+                <tr>
+                    <td>Word count (latest snapshot)</td>
+                    <td>{word_count}</td>
+                </tr>
+            </tbody>
+        </table>
+    </div>
+    """
+    return html
+```
+
+## Testing Your Plugin
+
+1. Place your plugin in one of the directories scanned by the plugin system
+2. Restart changedetection.io
+3. Go to the Edit page of a watch and check the Stats tab to see your content

changedetectionio/blueprint/ui/edit.py

@@ -233,6 +233,9 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
             # Only works reliably with Playwright
 
+            # Import the global plugin system
+            from changedetectionio.pluggy_interface import collect_ui_edit_stats_extras
+            
             template_args = {
                 'available_processors': processors.available_processors(),
                 'available_timezones': sorted(available_timezones()),
@@ -250,6 +253,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
                 'settings_application': datastore.data['settings']['application'],
                 'system_has_playwright_configured': os.getenv('PLAYWRIGHT_DRIVER_URL'),
                 'system_has_webdriver_configured': os.getenv('WEBDRIVER_URL'),
+                'ui_edit_stats_extras': collect_ui_edit_stats_extras(watch),
                 'visual_selector_data_ready': datastore.visualselector_data_is_ready(watch_uuid=uuid),
                 'timezone_default_config': datastore.data['settings']['application'].get('timezone'),
                 'using_global_webdriver_wait': not default['webdriver_delay'],

changedetectionio/conditions/__init__.py

@@ -102,12 +102,31 @@ def execute_ruleset_against_all_plugins(current_watch_uuid: str, application_dat
         if complete_rules:
             # Give all plugins a chance to update the data dict again (that we will test the conditions against)
             for plugin in plugin_manager.get_plugins():
-                new_execute_data = plugin.add_data(current_watch_uuid=current_watch_uuid,
+                try:
-                                                   application_datastruct=application_datastruct,
+                    import concurrent.futures
-                                                   ephemeral_data=ephemeral_data)
+                    import time
-
+                    
-                if new_execute_data and isinstance(new_execute_data, dict):
+                    with concurrent.futures.ThreadPoolExecutor() as executor:
-                    EXECUTE_DATA.update(new_execute_data)
+                        future = executor.submit(
+                            plugin.add_data,
+                            current_watch_uuid=current_watch_uuid,
+                            application_datastruct=application_datastruct,
+                            ephemeral_data=ephemeral_data
+                        )
+                        
+                        # Set a timeout of 10 seconds
+                        try:
+                            new_execute_data = future.result(timeout=10)
+                            if new_execute_data and isinstance(new_execute_data, dict):
+                                EXECUTE_DATA.update(new_execute_data)
+                        except concurrent.futures.TimeoutError:
+                            # The plugin took too long, abort processing for this watch
+                            raise Exception(f"Plugin {plugin.__class__.__name__} took more than 10 seconds to run.")
+                except Exception as e:
+                    # Log the error but continue with the next plugin
+                    import logging
+                    logging.error(f"Error executing plugin {plugin.__class__.__name__}: {str(e)}")
+                    continue
 
             # Create the ruleset
             ruleset = convert_to_jsonlogic(logic_operator=logic_operator, rule_dict=complete_rules)
@@ -132,3 +151,18 @@ for plugin in plugin_manager.get_plugins():
     if isinstance(new_field_choices, list):
         field_choices.extend(new_field_choices)
 
+def collect_ui_edit_stats_extras(watch):
+    """Collect and combine HTML content from all plugins that implement ui_edit_stats_extras"""
+    extras_content = []
+    
+    for plugin in plugin_manager.get_plugins():
+        try:
+            content = plugin.ui_edit_stats_extras(watch=watch)
+            if content:
+                extras_content.append(content)
+        except Exception as e:
+            # Skip plugins that don't implement the hook or have errors
+            pass
+            
+    return "\n".join(extras_content) if extras_content else ""
+

changedetectionio/conditions/pluggy_interface.py

@@ -1,5 +1,8 @@
 import pluggy
-from . import default_plugin  # Import the default plugin
+import os
+import importlib
+import sys
+from . import default_plugin
 
 # ✅ Ensure that the namespace in HookspecMarker matches PluginManager
 PLUGIN_NAMESPACE = "changedetectionio_conditions"
@@ -30,6 +33,11 @@ class ConditionsSpec:
     def add_data(current_watch_uuid, application_datastruct, ephemeral_data):
         """Add to the datadict"""
         pass
+        
+    @hookspec
+    def ui_edit_stats_extras(watch):
+        """Return HTML content to add to the stats tab in the edit view"""
+        pass
 
 # ✅ Set up Pluggy Plugin Manager
 plugin_manager = pluggy.PluginManager(PLUGIN_NAMESPACE)
@@ -40,5 +48,27 @@ plugin_manager.add_hookspecs(ConditionsSpec)
 # ✅ Register built-in plugins manually
 plugin_manager.register(default_plugin, "default_plugin")
 
+# ✅ Load plugins from the plugins directory
+def load_plugins_from_directory():
+    plugins_dir = os.path.join(os.path.dirname(__file__), 'plugins')
+    if not os.path.exists(plugins_dir):
+        return
+        
+    # Get all Python files (excluding __init__.py)
+    for filename in os.listdir(plugins_dir):
+        if filename.endswith(".py") and filename != "__init__.py":
+            module_name = filename[:-3]  # Remove .py extension
+            module_path = f"changedetectionio.conditions.plugins.{module_name}"
+            
+            try:
+                module = importlib.import_module(module_path)
+                # Register the plugin with pluggy
+                plugin_manager.register(module, module_name)
+            except (ImportError, AttributeError) as e:
+                print(f"Error loading plugin {module_name}: {e}")
+
+# Load plugins from the plugins directory
+load_plugins_from_directory()
+
 # ✅ Discover installed plugins from external packages (if any)
 plugin_manager.load_setuptools_entrypoints(PLUGIN_NAMESPACE)

changedetectionio/conditions/plugins/__init__.py

@@ -0,0 +1 @@
+# Import plugins package to make them discoverable

changedetectionio/conditions/plugins/levenshtein_plugin.py

@@ -0,0 +1,102 @@
+import pluggy
+from loguru import logger
+
+# Support both plugin systems
+conditions_hookimpl = pluggy.HookimplMarker("changedetectionio_conditions")
+global_hookimpl = pluggy.HookimplMarker("changedetectionio")
+
+def levenshtein_ratio_recent_history(watch, incoming_text=None):
+    try:
+        from Levenshtein import ratio, distance
+        k = list(watch.history.keys())
+        if len(k) >= 2:
+            # When called from ui_edit_stats_extras, we don't have incoming_text
+            if incoming_text is None:
+                a = watch.get_history_snapshot(timestamp=k[-1])  # Latest snapshot
+                b = watch.get_history_snapshot(timestamp=k[-2])  # Previous snapshot
+            else:
+                a = watch.get_history_snapshot(timestamp=k[-2]) # Second newest, incoming_text will be "newest"
+                b = incoming_text
+            
+            distance_value = distance(a, b)
+            ratio_value = ratio(a, b)
+            return {
+                'distance': distance_value,
+                'ratio': ratio_value,
+                'percent_similar': round(ratio_value * 100, 2)
+            }
+    except Exception as e:
+        logger.warning(f"Unable to calc similarity: {str(e)}")
+
+    return ''
+
+@conditions_hookimpl
+def register_operators():
+    pass
+
+@conditions_hookimpl
+def register_operator_choices():
+    pass
+
+
+@conditions_hookimpl
+def register_field_choices():
+    return [
+        ("levenshtein_ratio", "Levenshtein - Text similarity ratio"),
+        ("levenshtein_distance", "Levenshtein - Text change distance"),
+    ]
+
+@conditions_hookimpl
+def add_data(current_watch_uuid, application_datastruct, ephemeral_data):
+    res = {}
+    watch = application_datastruct['watching'].get(current_watch_uuid)
+    # ephemeral_data['text'] will be the current text after filters, they may have edited filters but not saved them yet etc
+
+    if watch and 'text' in ephemeral_data:
+        lev_data = levenshtein_ratio_recent_history(watch, ephemeral_data['text'])
+        if isinstance(lev_data, dict):
+            res['levenshtein_ratio'] = lev_data.get('ratio', 0)
+            res['levenshtein_similarity'] = lev_data.get('percent_similar', 0)
+            res['levenshtein_distance'] = lev_data.get('distance', 0)
+
+    return res
+
+@global_hookimpl
+def ui_edit_stats_extras(watch):
+    """Add Levenshtein stats to the UI using the global plugin system"""
+    """Generate the HTML for Levenshtein stats - shared by both plugin systems"""
+    if len(watch.history.keys()) < 2:
+        return "<p>Not enough history to calculate Levenshtein metrics</p>"
+    
+    try:
+        lev_data = levenshtein_ratio_recent_history(watch)
+        if not lev_data or not isinstance(lev_data, dict):
+            return "<p>Unable to calculate Levenshtein metrics</p>"
+            
+        html = f"""
+        <div class="levenshtein-stats">
+            <h4>Levenshtein Text Similarity Details</h4>
+            <table class="pure-table">
+                <tbody>
+                    <tr>
+                        <td>Raw distance (edits needed)</td>
+                        <td>{lev_data['distance']}</td>
+                    </tr>
+                    <tr>
+                        <td>Similarity ratio</td>
+                        <td>{lev_data['ratio']:.4f}</td>
+                    </tr>
+                    <tr>
+                        <td>Percent similar</td>
+                        <td>{lev_data['percent_similar']}%</td>
+                    </tr>
+                </tbody>
+            </table>
+            <p style="font-size: 80%;">Levenshtein metrics compare the last two snapshots, measuring how many character edits are needed to transform one into the other.</p>
+        </div>
+        """
+        return html
+    except Exception as e:
+        logger.error(f"Error generating Levenshtein UI extras: {str(e)}")
+        return "<p>Error calculating Levenshtein metrics</p>"
+        

changedetectionio/conditions/plugins/wordcount_plugin.py

@@ -0,0 +1,82 @@
+import pluggy
+from loguru import logger
+
+# Support both plugin systems
+conditions_hookimpl = pluggy.HookimplMarker("changedetectionio_conditions")
+global_hookimpl = pluggy.HookimplMarker("changedetectionio")
+
+def count_words_in_history(watch, incoming_text=None):
+    """Count words in snapshot text"""
+    try:
+        if incoming_text is not None:
+            # When called from add_data with incoming text
+            return len(incoming_text.split())
+        elif watch.history.keys():
+            # When called from UI extras to count latest snapshot
+            latest_key = list(watch.history.keys())[-1]
+            latest_content = watch.get_history_snapshot(latest_key)
+            return len(latest_content.split())
+        return 0
+    except Exception as e:
+        logger.error(f"Error counting words: {str(e)}")
+        return 0
+
+# Implement condition plugin hooks
+@conditions_hookimpl
+def register_operators():
+    # No custom operators needed
+    return {}
+
+@conditions_hookimpl
+def register_operator_choices():
+    # No custom operator choices needed
+    return []
+
+@conditions_hookimpl
+def register_field_choices():
+    # Add a field that will be available in conditions
+    return [
+        ("word_count", "Word count of content"),
+    ]
+
+@conditions_hookimpl
+def add_data(current_watch_uuid, application_datastruct, ephemeral_data):
+    """Add word count data for conditions"""
+    result = {}
+    watch = application_datastruct['watching'].get(current_watch_uuid)
+    
+    if watch and 'text' in ephemeral_data:
+        word_count = count_words_in_history(watch, ephemeral_data['text'])
+        result['word_count'] = word_count
+    
+    return result
+
+def _generate_stats_html(watch):
+    """Generate the HTML content for the stats tab"""
+    word_count = count_words_in_history(watch)
+    
+    html = f"""
+    <div class="word-count-stats">
+        <h4>Content Analysis</h4>
+        <table class="pure-table">
+            <tbody>
+                <tr>
+                    <td>Word count (latest snapshot)</td>
+                    <td>{word_count}</td>
+                </tr>
+            </tbody>
+        </table>
+        <p style="font-size: 80%;">Word count is a simple measure of content length, calculated by splitting text on whitespace.</p>
+    </div>
+    """
+    return html
+
+@conditions_hookimpl
+def ui_edit_stats_extras(watch):
+    """Add word count stats to the UI through conditions plugin system"""
+    return _generate_stats_html(watch)
+
+@global_hookimpl
+def ui_edit_stats_extras(watch):
+    """Add word count stats to the UI using the global plugin system"""
+    return _generate_stats_html(watch)

changedetectionio/pluggy_interface.py

@@ -0,0 +1,82 @@
+import pluggy
+import os
+import importlib
+import sys
+
+# Global plugin namespace for changedetection.io
+PLUGIN_NAMESPACE = "changedetectionio"
+
+hookspec = pluggy.HookspecMarker(PLUGIN_NAMESPACE)
+hookimpl = pluggy.HookimplMarker(PLUGIN_NAMESPACE)
+
+
+class ChangeDetectionSpec:
+    """Hook specifications for extending changedetection.io functionality."""
+
+    @hookspec
+    def ui_edit_stats_extras(watch):
+        """Return HTML content to add to the stats tab in the edit view.
+        
+        Args:
+            watch: The watch object being edited
+            
+        Returns:
+            str: HTML content to be inserted in the stats tab
+        """
+        pass
+
+
+# Set up Plugin Manager
+plugin_manager = pluggy.PluginManager(PLUGIN_NAMESPACE)
+
+# Register hookspecs
+plugin_manager.add_hookspecs(ChangeDetectionSpec)
+
+# Load plugins from subdirectories
+def load_plugins_from_directories():
+    # Dictionary of directories to scan for plugins
+    plugin_dirs = {
+        'conditions': os.path.join(os.path.dirname(__file__), 'conditions', 'plugins'),
+        # Add more plugin directories here as needed
+    }
+    
+    # Note: Removed the direct import of example_word_count_plugin as it's now in the conditions/plugins directory
+    
+    for dir_name, dir_path in plugin_dirs.items():
+        if not os.path.exists(dir_path):
+            continue
+            
+        # Get all Python files (excluding __init__.py)
+        for filename in os.listdir(dir_path):
+            if filename.endswith(".py") and filename != "__init__.py":
+                module_name = filename[:-3]  # Remove .py extension
+                module_path = f"changedetectionio.{dir_name}.plugins.{module_name}"
+                
+                try:
+                    module = importlib.import_module(module_path)
+                    # Register the plugin with pluggy
+                    plugin_manager.register(module, module_name)
+                except (ImportError, AttributeError) as e:
+                    print(f"Error loading plugin {module_name}: {e}")
+
+# Load plugins
+load_plugins_from_directories()
+
+# Discover installed plugins from external packages (if any)
+plugin_manager.load_setuptools_entrypoints(PLUGIN_NAMESPACE)
+
+# Helper function to collect UI stats extras from all plugins
+def collect_ui_edit_stats_extras(watch):
+    """Collect and combine HTML content from all plugins that implement ui_edit_stats_extras"""
+    extras_content = []
+    
+    # Get all plugins that implement the ui_edit_stats_extras hook
+    results = plugin_manager.hook.ui_edit_stats_extras(watch=watch)
+    
+    # If we have results, add them to our content
+    if results:
+        for result in results:
+            if result:  # Skip empty results
+                extras_content.append(result)
+            
+    return "\n".join(extras_content) if extras_content else ""

changedetectionio/templates/edit.html

@@ -450,6 +450,13 @@ Math: {{ 1 + 1 }}") }}
                         </tr>
                         </tbody>
                     </table>
+
+                    {% if ui_edit_stats_extras %}
+                    <div class="plugin-stats-extras"> <!-- from pluggy plugin -->
+                        {{ ui_edit_stats_extras|safe }}
+                    </div>
+                    {% endif %}
+
                     {% if watch.history_n %}
                         <p>
                              <a href="{{url_for('ui.ui_edit.watch_get_latest_html', uuid=uuid)}}" class="pure-button button-small">Download latest HTML snapshot</a>

changedetectionio/tests/test_conditions.py

@@ -45,11 +45,15 @@ def set_number_out_of_range_response(number="150"):
         f.write(test_return_data)
 
 
+def test_setup(client, live_server):
+    """Test that both text and number conditions work together with AND logic."""
+    live_server_setup(live_server)
+
 def test_conditions_with_text_and_number(client, live_server):
     """Test that both text and number conditions work together with AND logic."""
     
     set_original_response("50")
-    live_server_setup(live_server)
+    #live_server_setup(live_server)
 
     test_url = url_for('test_endpoint', _external=True)
 
@@ -195,3 +199,40 @@ def test_condition_validate_rule_row(client, live_server):
 
 
 
+
+# If there was only a change in the whitespacing, then we shouldnt have a change detected
+def test_wordcount_conditions_plugin(client, live_server, measure_memory_usage):
+    #live_server_setup(live_server)
+
+    test_return_data = """<html>
+       <body>
+     Some initial text<br>
+     <p>Which is across multiple lines</p>
+     <br>
+     So let's see what happens.  <br>
+     </body>
+     </html>
+    """
+
+    with open("test-datastore/endpoint-content.txt", "w") as f:
+        f.write(test_return_data)
+
+    # Add our URL to the import page
+    test_url = url_for('test_endpoint', _external=True)
+    res = client.post(
+        url_for("imports.import_page"),
+        data={"urls": test_url},
+        follow_redirects=True
+    )
+    assert b"1 Imported" in res.data
+
+    # Give the thread time to pick it up
+    wait_for_all_checks(client)
+
+    # Check it saved
+    res = client.get(
+        url_for("ui.ui_edit.edit_page", uuid="first"),
+    )
+
+    # Assert the word count is counted correctly
+    assert b'<td>13</td>' in res.data