fix server_default

guniflask/modelgen.py

@@ -10,6 +10,7 @@
 import sqlalchemy
 from sqlalchemy import ForeignKeyConstraint, UniqueConstraint, PrimaryKeyConstraint, CheckConstraint, ForeignKey
 import inflect
+from sqlalchemy.util import OrderedDict
 
 from guniflask.utils.template import string_camelcase, string_lowercase_underscore
 
@@ -56,7 +57,7 @@ def render(self, path):
             module_name = convert_to_valid_identifier(model.table.name)
             with open(join(path, module_name + '.py'), 'w', encoding='utf-8') as f:
                 f.write('# coding=utf-8\n\n')
-                f.write(self.render_imports())
+                f.write(self.render_imports(model))
                 tables_content = self.render_secondary_tables(model)
                 if tables_content:
                     f.write('\n')
@@ -69,8 +70,22 @@ def render(self, path):
             for m in model_modules:
                 f.write('from .{} import {}\n'.format(m['module'], m['class']))
 
-    def render_imports(self):
-        return 'from {} import db\n'.format(self.name)
+    def render_imports(self, model):
+        d = OrderedDict()
+        for col in model.table.columns:
+            if col.server_default:
+                d.setdefault('sqlalchemy', ('text', '_text'))
+
+        imports = ''
+        for k, v in d.items():
+            if isinstance(v, tuple):
+                imports += 'from {} import {} as {}\n'.format(k, v[0], v[1])
+            else:
+                imports += 'from {} import {}\n'.format(k, v)
+        if len(d) > 0:
+            imports += '\n'
+        imports += 'from {} import db\n'.format(self.name)
+        return imports
 
     def render_model(self, model):
         header_str = "class {}(db.Model):\n".format(model.class_name)
@@ -122,7 +137,12 @@ def render_column(self, column, show_name=False):
         if column.comment:
             kwargs.append('comment')
         if column.server_default:
-            server_default = 'server_default="{}"'.format(str(column.server_default.arg))
+            default_expr = self.get_compiled_expression(column.server_default.arg)
+            if '\n' in default_expr:
+                server_default = 'server_default=text("""\\\n{0}""")'.format(default_expr)
+            else:
+                default_expr = default_expr.replace('"', '\\"')
+                server_default = 'server_default=_text("{0}")'.format(default_expr)
         extra_kwargs = self.get_extra_column_kwargs(column)
         return "db.Column({})".format(', '.join(([repr(column.name)] if show_name else []) +
                                                 [self.render_column_type(column.type)] +
@@ -162,6 +182,10 @@ def render_relationship(self, relationship):
                                 sorted(relationship.kwargs.keys())])
         return '{} = db.relationship({})'.format(relationship.preferred_name, kwargs_str)
 
+    def get_compiled_expression(self, statement):
+        return str(statement.compile(
+            self.metadata.bind, compile_kwargs={"literal_binds": True}))
+
 
 def convert_to_valid_identifier(name):
     name = string_lowercase_underscore(name)