Update docs to include info on new functionality.

docs/bot-basics.md

@@ -34,6 +34,8 @@ By default, loop runs every few seconds (`internals.process_throttle_secs`) and
 * Check timeouts for open orders.
   * Calls `check_entry_timeout()` strategy callback for open entry orders.
   * Calls `check_exit_timeout()` strategy callback for open exit orders.
+* Check readjustment request for open orders.
+  * Calls `readjust_entry_price()` strategy callback for open entry orders.
 * Verifies existing positions and eventually places exit orders.
   * Considers stoploss, ROI and exit-signal, `custom_exit()` and `custom_stoploss()`.
   * Determine exit-price based on `exit_pricing` configuration setting or by using the `custom_exit_price()` callback.

docs/strategy-callbacks.md

@@ -16,6 +16,7 @@ Currently available callbacks:
 * [`confirm_trade_entry()`](#trade-entry-buy-order-confirmation)
 * [`confirm_trade_exit()`](#trade-exit-sell-order-confirmation)
 * [`adjust_trade_position()`](#adjust-trade-position)
+* [`readjust_entry_price()`](#readjust-entry-price)
 * [`leverage()`](#leverage-callback)
 
 !!! Tip "Callback calling sequence"
@@ -689,6 +690,46 @@ class DigDeeperStrategy(IStrategy):
 
 ```
 
+## Readjust Entry Price
+
+The `readjust_entry_price()` callback may be used by strategy developer to refresh/replace limit orders upon arrival of new candles.
+Be aware that `custom_entry_price()` is still the one dictating initial entry limit order price target at the time of entry trigger.
+
+!!! Warning This mechanism will not trigger if previous orders were partially or fully filled.
+
+!!! Warning Entry `unfilledtimeout` mechanism takes precedence over this. Be sure to update timeout values to match your expectancy.
+
+```python
+from freqtrade.persistence import Trade
+from datetime import timedelta
+
+class AwesomeStrategy(IStrategy):
+
+    # ... populate_* methods
+
+    def readjust_entry_price(self, pair: str, current_time: datetime, proposed_rate: float,
+                           entry_tag: Optional[str], side: str, **kwargs) -> float:
+        """
+        Entry price readjustment logic, returning the readjusted entry price.
+
+        :param pair: Pair that's currently analyzed
+        :param trade: Trade object.
+        :param current_time: datetime object, containing the current datetime
+        :param proposed_rate: Rate, calculated based on pricing settings in exit_pricing.
+        :param entry_tag: Optional entry_tag (buy_tag) if provided with the buy signal.
+        :param side: 'long' or 'short' - indicating the direction of the proposed trade
+        :param **kwargs: Ensure to keep this here so updates to this won't break your strategy.
+        :return float: New entry price value if provided
+
+        """
+        # Limit orders to use and follow SMA200 as price target for the first 10 minutes since entry trigger for BTC/USDT pair.
+        if pair == 'BTC/USDT' and entry_tag == 'long_sma200' and side == 'long' and (current_time - timedelta(minutes=10) > trade.open_date_utc:
+            dataframe, _ = self.dp.get_analyzed_dataframe(pair=pair, timeframe=self.timeframe)
+            current_candle = dataframe.iloc[-1].squeeze()
+            return current_candle['sma_200']
+        return proposed_rate
+```
+
 ## Leverage Callback
 
 When trading in markets that allow leverage, this method must return the desired Leverage (Defaults to 1 -> No leverage).