fix ordering of subprojects in project list

input/projects/3d-printing.md

 parent: projects
 position: 10
 child-id: 3d-printing
+sort-order: position
 ---
 
 In 2016 I've started experimenting with 3D printers.
 Here are all the articles that are part of my 3D printing series:
 
 <!--%
-printMenuPositional()
+printMenu()
 %-->
 
 If you're interested in my 3D print designs, take a look [at my Thingiverse account](https://www.thingiverse.com/xythobuz/designs) or my [Git Repository](https://git.xythobuz.de/thomas/3d-print-designs).

input/projects/input_devices.md

 parent: projects
 position: 15
 child-id: input_devices
+sort-order: date
 ---
 
 One of the recurring topics in my projects are different kind of input devices.
 Here you can find all pages in this category.
 
 <!--%
-printMenuDate()
+printMenu()
 %-->
 
 The following pages are also related to this topic.

input/projects/quadcopters.md

 parent: projects
 position: 20
 child-id: quadcopters
+sort-order: position
 ---
 
 In the last couple of years I built multiple quadcopters and some other related flying remote-controlled model vehicles.
 Of course I'm not flying illegally, I have a model flight insurance and I am a registered UAV pilot in the European Union! 👮
 
 <!--%
-printMenuPositional()
+printMenu()
 %-->
 
 The following projects and blog posts are also related to my Quadcopter endeavours.

input/projects/smarthome.md

 parent: projects
 position: 50
 child-id: smarthome
+sort-order: position
 ---
 
 With the appearance of cheap WiFi-capable microcontrollers in recent years, like the ESP8266 and the ESP32, the Internet of Things and Smart Home automation have been on my mind.
 The pages in this category document different parts of my setup at home.
 
 <!--%
-printMenuPositional()
+printMenu()
 %-->

input/projects/xyrobot.md

 date: 2011-07-28
 update: 2012-08-30
 child-id: xyrobot
+sort-order: position
 ---
 
 This is my robot project. A self-made PCB with an AtMega2560 controls everything. The robot has a [Bluetooth module][1], a [Gameboy Camera][2] and my [RAM module][3]. I bought the [RN-KeyLCD][4] and the [RN-VN2][5] from [Roboternetz][6].

macros.py

 
         # print subpages for these top-level items
         subpages = [sub for sub in enpages if sub.get("parent", "none") == p.get("child-id", "unknown")]
+        order = p.get("sort-order", "date")
+        if order == "position":
+            subpages.sort(key=lambda p: p["position"])
+        else:
+            subpages.sort(key=lambda p: p["date"], reverse = True)
         if len(subpages) > 0:
             print("<ul>")
             for sp in subpages:
 
         # print subpages for these top-level items
         subpages = [sub for sub in enpages if sub.get("parent", "none") == p.get("child-id", "unknown")]
-        subpages.sort(key=lambda p: [p.get("date", "9999-01-01")], reverse = True)
+        order = p.get("sort-order", "date")
+        if order == "position":
+            subpages.sort(key=lambda p: p["position"])
+        else:
+            subpages.sort(key=lambda p: p["date"], reverse = True)
         if len(subpages) > 0:
             print("<ul>")
             for sp in subpages:
 
     print("</ul>")
 
-def printMenu(mpages = None, sortKey = None, sortReverse = True):
+def printMenuGeneric(mpages = None, sortKey = None, sortReverse = True):
     if mpages == None:
         mpages = [p for p in pages if p.get("parent", "__none__") == page["child-id"] and p.lang == "en"]
     if sortKey != None:
 
 def printMenuDate(mpages = None, sortReverse = True):
     sortKey = lambda p: p["date"]
-    printMenu(mpages, sortKey, sortReverse)
+    printMenuGeneric(mpages, sortKey, sortReverse)
 
 def printMenuPositional(mpages = None):
-    printMenu(mpages, lambda p: int(p["position"]), False)
+    printMenuGeneric(mpages, lambda p: int(p["position"]), False)
+
+def printMenu(mpages = None):
+    order = page.get("sort-order", "date")
+    if order == "position":
+        printMenuPositional(mpages)
+    else:
+        printMenuDate(mpages)
 
 def printRobotMenuEnglish():
     mpages = [p for p in pages if p.get("parent", "") == "xyrobot" and p.lang == "en"]