create compatibility code

freqtrade/resolvers/strategy_resolver.py

@@ -50,6 +50,14 @@ class StrategyResolver(IResolver):
         if 'ask_strategy' not in config:
             config['ask_strategy'] = {}
 
+        if hasattr(strategy, 'ticker_interval') and not hasattr(strategy, 'timeframe'):
+            # Assign ticker_interval to timeframe to keep compatibility
+            if 'timeframe' not in config:
+                logger.warning(
+                    "DEPRECATED: Please migrate to using timeframe instead of ticker_interval."
+                    )
+                strategy.timeframe = strategy.ticker_interval
+
         # Set attributes
         # Check if we need to override configuration
         #             (Attribute name,                    default,     subkey)
@@ -80,6 +88,9 @@ class StrategyResolver(IResolver):
                 StrategyResolver._override_attribute_helper(strategy, config,
                                                             attribute, default)
 
+        # Assign deprecated variable - to not break users code relying on this.
+        strategy.ticker_interval = strategy.timeframe
+
         # Loop this list again to have output combined
         for attribute, _, subkey in attributes:
             if subkey and attribute in config[subkey]: