Add module to generate a graph from a model

acceptance_tests/app/Dockerfile

@@ -20,6 +20,9 @@ ENV DEVELOPMENT 0
 
 # Step #2 copy the rest of the files (watch for the .dockerignore)
 COPY . /app
-RUN python /app/setup.py install
+
+RUN python ./setup.py install && \
+    ./models_graph.py > models.dot && \
+    ./models_graph.py Hello > models_hello.dot
 
 CMD ["c2cwsgiutils_run"]

acceptance_tests/app/models_graph.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python3
+from c2cwsgiutils.models_graph import generate_model_graph
+
+from c2cwsgiutils_app import models
+
+
+def main():
+    generate_model_graph(models)
+
+
+main()

c2cwsgiutils/models_graph.py

@@ -0,0 +1,82 @@
+import inspect
+import sqlalchemy as sa
+import sys
+
+
+def generate_model_graph(module):
+    if len(sys.argv) == 1:
+        base_name = 'Base'
+    elif len(sys.argv) == 2:
+        base_name = sys.argv[1]
+    else:
+        print("Invalid parameters\nUsage: %s [base_class]" % sys.argv[0])
+        exit(1)
+
+    _generate_model_graph(module, getattr(module, base_name))
+
+
+def _generate_model_graph(module, base):
+    print("""
+    digraph {
+        rankdir=BT;
+    """)
+
+    interesting = {
+        getattr(module, symbol_name)
+        for symbol_name in dir(module)
+        if _is_interesting(getattr(module, symbol_name), base)
+        }
+
+    for symbol in list(interesting):
+        symbol = getattr(module, symbol.__name__)
+        if _is_interesting(symbol, base):
+            _print_node(symbol, interesting)
+
+    print("}")
+
+
+def _print_node(symbol, interesting):
+    print('%s [label="%s", shape=box];' % (symbol.__name__, _get_table_desc(symbol)))
+    for parent in symbol.__bases__:
+        if parent != object:
+            if parent not in interesting:
+                _print_node(parent, interesting)
+                interesting.add(parent)
+            print("%s -> %s;" % (symbol.__name__, parent.__name__))
+
+
+def _is_interesting(what, base):
+    return inspect.isclass(what) and issubclass(what, base)
+
+
+def _get_table_desc(symbol):
+    cols = [symbol.__name__, ""] + _get_local_cols(symbol)
+
+    return "\\n".join(cols)
+
+
+def _get_all_cols(symbol):
+    cols = []
+
+    for member_name in symbol.__dict__:
+        member = getattr(symbol, member_name)
+        if member_name in ('__table__', 'metadata'):
+            pass
+        elif isinstance(member, sa.sql.schema.SchemaItem):
+            cols.append(member_name + ('[null]' if member.nullable else ''))
+        elif isinstance(member, sa.orm.attributes.InstrumentedAttribute):
+            nullable = member.property.columns[0].nullable \
+                if isinstance(member.property, sa.orm.ColumnProperty) \
+                else False
+            link = not isinstance(member.property, sa.orm.ColumnProperty)
+            cols.append(member_name + (' [null]' if nullable else '') + (' ->' if link else ''))
+
+    return cols
+
+
+def _get_local_cols(symbol):
+    result = set(_get_all_cols(symbol))
+    for parent in symbol.__bases__:
+        result -= set(_get_all_cols(parent))
+
+    return sorted(list(result))

setup.py

@@ -1,7 +1,7 @@
 from setuptools import setup, find_packages
 
 
-version = '0.4.0'
+version = '0.5.0'
 
 setup(
     name='c2cwsgiutils',