Understanding the schemas

ColanderAlchemy allows creating Colander schemas directly from SQLAlchemy model classes.

Additionally, c2cgeoform provides its own classes with extended features. A basic use case schema creation will look like:

from model import MyClass
schema = GeoFormSchemaNode(MyClass)

See the following API to understand what is going on behind the scene.

class c2cgeoform.schema.GeoFormSchemaNode(*args, **kw)

An SQLAlchemySchemaNode with deferred request and dbsession properties. This will allow defining schemas that requires the request and dbsession at module-scope.

Example usage:

schema = GeoFormSchemaNode(MyModel)

def create_form(request, dbsession):
    return Form(
        schema = schema.bind(
            request=request,
            dbsession=request.dbsession),
        ...
    )

add_unique_validator(column, column_id)

Adds an unique validator on this schema instance.

column

SQLAlchemy ColumnProperty that should be unique.

column_id

SQLAlchemy MapperProperty that is used to recognize the entity, basically the primary key ColumnProperty.

class c2cgeoform.schema.GeoFormManyToManySchemaNode(class_, includes=None, *args, **kw)

A GeoFormSchemaNode that properly handles many to many relationships.

includes:

Default to primary key name(s) only.

objectify(dict_, context=None)

Method override that returns the existing ORM class instance instead of creating a new one.