write default values in the configs

Summary:
show the default values in the generated docs.
in case no default is indicated, fallback to different type dependednt
empty values, such as 0 for Int, false for Bool, "empty list" for string lists

the generated docs will look like:
* '''ItemsGeometriesHorizontal''' (''String'', default ''empty string'')

Reviewers: davidedmundson, #plasma

Reviewed By: davidedmundson, #plasma

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D2770

doc/config_update_tool/extract_config.py

@@ -48,12 +48,24 @@ for plasmoid in os.listdir(root):
                 if (defaultTags.length > 0 and defaultTags[0].childNodes.length > 0):
                     default = defaultTags[0].childNodes[0].data
 
+                if (default == ""):
+                    if (type == "Bool"):
+                        default = "false"
+                    elif (type == "Int"):
+                        default = "0"
+                    elif (type == "StringList"):
+                        default = "empty list"
+                    elif (type == "String"):
+                        default = "empty string"
+                    else:
+                        default = "null"
+
                 labelTags = entry.getElementsByTagName("label")
                 if (labelTags.length > 0 and labelTags[0].childNodes.length > 0):
                     description = labelTags[0].childNodes[0].data
 
 
-                print ("* '''%s''' (''%s'') %s" % (name , type, description))
+                print ("* '''%s''' (''%s'', default ''%s'') %s" % (name , type, default, description))
     except IOError:
         sys.stderr.write("No config in " + plasmoid +"\n")
     #abort on other errors so we can find them