Added custom method for updating block state from TileEntity state changes.

src/main/java/appeng/block/AEBaseTileBlock.java

@@ -327,4 +327,28 @@ public abstract class AEBaseTileBlock<T extends AEBaseTile> extends AEBaseBlock
 		return this.getTileEntity( w, pos );
 	}
 
+	/**
+	 * Returns the BlockState based on the given BlockState while considering the state of the given TileEntity.
+	 *
+	 * If the given TileEntity is not of the right type for this block, the state is returned unchanged,
+	 * this is also the case if the given block state does not belong to this block.
+	 */
+	public final BlockState getTileEntityBlockState(BlockState current, TileEntity te) {
+		if (current.getBlock() != this || !tileEntityClass.isInstance(te)) {
+			return current;
+		}
+
+		return updateBlockStateFromTileEntity(current, tileEntityClass.cast(te));
+	}
+
+	/**
+	 * Reimplement this in subclasses to allow tile-entities to update the state of their block when their own
+	 * state changes.
+	 *
+	 * It is guaranteed that te is not-null and the block of the given block state is this exact block instance.
+	 */
+	protected BlockState updateBlockStateFromTileEntity(BlockState currentState, T te) {
+		return currentState;
+	}
+
 }

src/main/java/appeng/block/storage/BlockChest.java

@@ -62,27 +62,20 @@ public class BlockChest extends AEBaseTileBlock<TileChest>
 	}
 
 	@Override
-	public BlockState updatePostPlacement(BlockState state, Direction facing, BlockState facingState, IWorld worldIn, BlockPos pos, BlockPos facingPos) {
-		// FIXME Check tile-entity updated prop
-
+	protected BlockState updateBlockStateFromTileEntity(BlockState currentState, TileChest te) {
 		DriveSlotState slotState = DriveSlotState.EMPTY;
 
-		TileChest te = this.getTileEntity( worldIn, pos );
-
-		if( te != null )
+		if( te.getCellCount() >= 1 )
 		{
-			if( te.getCellCount() >= 1 )
-			{
-				slotState = DriveSlotState.fromCellStatus( te.getCellStatus( 0 ) );
-			}
-			// Power-state has to be checked separately
-			if( !te.isPowered() && slotState != DriveSlotState.EMPTY )
-			{
-				slotState = DriveSlotState.OFFLINE;
-			}
+			slotState = DriveSlotState.fromCellStatus( te.getCellStatus( 0 ) );
+		}
+		// Power-state has to be checked separately
+		if( !te.isPowered() && slotState != DriveSlotState.EMPTY )
+		{
+			slotState = DriveSlotState.OFFLINE;
 		}
 
-		return state.with( SLOT_STATE, slotState );
+		return currentState.with( SLOT_STATE, slotState );
 	}
 
 	@Override