221225

Author: FalkLiebezeit

14 - Databases/Momox/momox_tags_viewer.py

@@ -1,78 +1,121 @@
 """
-Flask Web App zur Anzeige aller Daten aus der Tags-Tabelle der momox.db Datenbank
+Flask Web App to display all data from the Tags table in the momox.db database.
+Optimized version with better error handling and resource management.
 """
 
-from flask import Flask, render_template
+from flask import Flask, render_template, jsonify
 import sqlite3
 import os
+from contextlib import contextmanager
 
 app = Flask(__name__)
+app.config['JSON_AS_ASCII'] = False  # Support for non-ASCII characters in JSON
 
-# Pfad zur Datenbank
+# Database path configuration
 DB_PATH = os.path.join(os.path.dirname(__file__), 'momox.db')
 
 
+@contextmanager
 def get_db_connection():
-    """Erstellt eine Verbindung zur SQLite-Datenbank"""
+    """Context manager for database connections to ensure proper resource cleanup."""
     conn = sqlite3.connect(DB_PATH)
-    conn.row_factory = sqlite3.Row  # Ermöglicht Zugriff auf Spalten über Namen
-    return conn
+    conn.row_factory = sqlite3.Row  # Enable column access by name
+    try:
+        yield conn
+    finally:
+        conn.close()
 
 
 @app.route('/')
 def index():
-    """Hauptseite - zeigt alle Tags aus der Datenbank"""
+    """Main page - displays all tags from the database in a formatted table."""
     try:
-        conn = get_db_connection()
-        cursor = conn.cursor()
-        
-        # Alle Daten aus der Tags-Tabelle abrufen
-        cursor.execute('SELECT * FROM Tags')
-        tags = cursor.fetchall()
-        
-        # Spaltennamen ermitteln
-        column_names = [description[0] for description in cursor.description]
-        
-        conn.close()
+        with get_db_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('SELECT * FROM Tags')
+            tags = cursor.fetchall()
+            column_names = [description[0] for description in cursor.description] if cursor.description else []
 
         return render_template('tags.html', tags=tags, columns=column_names)
 
     except sqlite3.Error as e:
-        return f"<h1>Datenbankfehler</h1><p>Fehler beim Zugriff auf die Datenbank: {str(e)}</p><p>Stellen Sie sicher, dass die Datei 'momox.db' im gleichen Verzeichnis wie die App existiert.</p>"
+        error_msg = f"""
+        <h1>Database Error</h1>
+        <p>Error accessing the database: {str(e)}</p>
+        <p>Please ensure that the 'momox.db' file exists in the same directory as the application.</p>
+        <p><a href="/">Try Again</a></p>
+        """
+        return error_msg, 500
     except Exception as e:
-        return f"<h1>Fehler</h1><p>Ein Fehler ist aufgetreten: {str(e)}</p>"
+        return f"<h1>Error</h1><p>An unexpected error occurred: {str(e)}</p><p><a href='/'>Return Home</a></p>", 500
 
 
-@app.route('/raw')
-def raw_data():
-    """Zeigt die Rohdaten als einfache Liste"""
+@app.route('/api/tags')
+def api_tags():
+    """API endpoint - returns tags data as JSON for programmatic access."""
     try:
-        conn = get_db_connection()
-        cursor = conn.cursor()
+        with get_db_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('SELECT * FROM Tags')
+            tags = cursor.fetchall()
+            column_names = [description[0] for description in cursor.description] if cursor.description else []
 
-        cursor.execute('SELECT * FROM Tags')
-        tags = cursor.fetchall()
+        # Convert rows to dictionaries
+        tags_list = [dict(zip(column_names, row)) for row in tags]
 
-        conn.close()
+        return jsonify({
+            'success': True,
+            'count': len(tags_list),
+            'columns': column_names,
+            'data': tags_list
+        })
+    
+    except sqlite3.Error as e:
+        return jsonify({
+            'success': False,
+            'error': f'Database error: {str(e)}'
+        }), 500
+
+
+@app.route('/raw')
+def raw_data():
+    """Displays raw data as a simple list."""
+    try:
+        with get_db_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('SELECT * FROM Tags')
+            tags = cursor.fetchall()
 
-        result = "<h1>Tags - Rohdaten</h1>"
-        result += f"<p>Anzahl der Einträge: {len(tags)}</p>"
-        result += "<ul>"
+        result = "<h1>Tags - Raw Data</h1>"
+        result += f"<p>Number of entries: {len(tags)}</p>"
+        result += "<ul style='font-family: monospace;'>"
         for tag in tags:
             result += f"<li>{dict(tag)}</li>"
         result += "</ul>"
-        result += '<br><a href="/">Zurück zur formatierten Ansicht</a>'
+        result += '<br><a href="/">← Back to formatted view</a> | <a href="/api/tags">View as JSON</a>'
 
         return result
 
     except sqlite3.Error as e:
-        return f"<h1>Datenbankfehler</h1><p>{str(e)}</p>"
+        return f"<h1>Database Error</h1><p>{str(e)}</p>", 500
+
+
+@app.errorhandler(404)
+def not_found(error):
+    """Custom 404 error handler."""
+    return "<h1>404 - Page Not Found</h1><p><a href='/'>Return Home</a></p>", 404
 
 
 if __name__ == '__main__':
-    # Überprüfen, ob die Datenbank existiert
+    # Check if database exists on startup
     if not os.path.exists(DB_PATH):
-        print(f"WARNUNG: Die Datenbank '{DB_PATH}' wurde nicht gefunden!")
-        print("Bitte stellen Sie sicher, dass die Datei 'momox.db' im gleichen Verzeichnis existiert.")
+        print(f"⚠️  WARNING: Database '{DB_PATH}' not found!")
+        print("Please ensure that 'momox.db' exists in the same directory.")
+    else:
+        print(f"✓ Database found: {DB_PATH}")
+    
+    print("\n🚀 Starting Flask server...")
+    print("📍 Access the app at: http://localhost:5000")
+    print("📊 API endpoint available at: http://localhost:5000/api/tags\n")
 
     app.run(debug=True, host='0.0.0.0', port=5000)