scripts/schema_diagram.py

   1 #! /usr/bin/python
   2 #
   3 # Schema diagram generator contributed by Stefan Seefeld of the fresco
   4 # project http://www.fresco.org/.
   5 #
   6 # It generates a 'dot file' that is then fed into the 'dot'
   7 # tool (http://www.graphviz.org) to generate a graph:
   8 #
   9 # %> ./schema.py
  10 # %> dot -Tps schema.dot -o schema.ps
  11 # %> gv schema.ps
  12 #
  13 import sys
  14 import roundup.instance
  15
  16 # open the instance
  17 instance = roundup.instance.open(sys.argv[1])
  18 db = instance.open()
  19
  20 # diagram preamble
  21 print 'digraph schema {'
  22 print 'size="8,6"'
  23 print 'node [shape="record" bgcolor="#ffe4c4" style=filled]'
  24 print 'edge [taillabel="1" headlabel="1" dir=back arrowtail=ediamond]'
  25
  26 # get all the classes
  27 types = db.classes.keys()
  28
  29 # one record node per class
  30 for i in range(len(types)):
  31     print 'node%d [label=\"{%s|}"]'%(i, types[i])
  32
  33 # now draw in the relations
  34 for name in db.classes.keys():
  35     type = db.classes[name]
  36     attributes = type.getprops()
  37     for a in attributes.keys():
  38         attribute = attributes[a]
  39         if isinstance(attribute, roundup.hyperdb.Link):
  40             print 'node%d -> node%d [label=%s]'%(types.index(name),
  41                                                  types.index(attribute.classname),
  42                                                  a)
  43         elif isinstance(attribute, roundup.hyperdb.Multilink):
  44             print 'node%d -> node%d [taillabel="*" label=%s]'%(types.index(name),
  45                                                  types.index(attribute.classname),
  46                                                  a)
  47 # all done
  48 print '}'