Added docs for Collections.

[philo.git] / philo / models / base.py

diff --git a/philo/models/base.py b/philo/models/base.py
index af1e880..46e9ac5 100644 (file)
--- a/philo/models/base.py
+++ b/philo/models/base.py
@@ -1,18 +1,20 @@
+from UserDict import DictMixin
+

 from django import forms
 from django import forms

-from django.db import models

 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.validators import RegexValidator
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.validators import RegexValidator

+from django.db import models

 from django.utils import simplejson as json
 from django.utils.encoding import force_unicode
 from django.utils import simplejson as json
 from django.utils.encoding import force_unicode

+from mptt.models import MPTTModel, MPTTModelBase, MPTTOptions
+

 from philo.exceptions import AncestorDoesNotExist
 from philo.models.fields import JSONField
 from philo.exceptions import AncestorDoesNotExist
 from philo.models.fields import JSONField

-from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter

 from philo.signals import entity_class_prepared
 from philo.signals import entity_class_prepared

+from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter

 from philo.validators import json_validator
 from philo.validators import json_validator

-from UserDict import DictMixin
-from mptt.models import MPTTModel, MPTTModelBase, MPTTOptions

 
 
 class Tag(models.Model):
 
 
 class Tag(models.Model):


@@ -38,10 +40,12 @@ class Titled(models.Model):
                abstract = True
 
 
                abstract = True
 
 

+#: An instance of :class:`ContentTypeRegistryLimiter` which is used to track the content types which can be related to by ForeignKeyValues and ManyToManyValues.

 value_content_type_limiter = ContentTypeRegistryLimiter()
 
 
 def register_value_model(model):
 value_content_type_limiter = ContentTypeRegistryLimiter()
 
 
 def register_value_model(model):

+       """Registers a model as a valid content type for a :class:`ForeignKeyValue` or :class:`ManyToManyValue` through the :data:`value_content_type_limiter`."""

        value_content_type_limiter.register_class(model)
 
 
        value_content_type_limiter.register_class(model)
 
 


@@ -49,21 +53,37 @@ register_value_model(Tag)
 
 
 def unregister_value_model(model):
 
 
 def unregister_value_model(model):

+       """Registers a model as a valid content type for a :class:`ForeignKeyValue` or :class:`ManyToManyValue` through the :data:`value_content_type_limiter`."""

        value_content_type_limiter.unregister_class(model)
 
 
 class AttributeValue(models.Model):
        value_content_type_limiter.unregister_class(model)
 
 
 class AttributeValue(models.Model):

+       """
+       This is an abstract base class for models that can be used as values for :class:`Attribute`\ s.
+       
+       AttributeValue subclasses are expected to supply access to a clean version of their value through an attribute called "value".
+       
+       """
+       
+       #: :class:`GenericRelation` to :class:`Attribute`

        attribute_set = generic.GenericRelation('Attribute', content_type_field='value_content_type', object_id_field='value_object_id')
        
        def set_value(self, value):
        attribute_set = generic.GenericRelation('Attribute', content_type_field='value_content_type', object_id_field='value_object_id')
        
        def set_value(self, value):

+               """Given a ``value``, sets the appropriate fields so that it can be correctly stored in the database."""

                raise NotImplementedError
        
        def value_formfields(self, **kwargs):
                raise NotImplementedError
        
        def value_formfields(self, **kwargs):

-               """Define any formfields that would be used to construct an instance of this value."""
+               """
+               Returns any formfields that would be used to construct an instance of this value.
+               
+               :returns: A dictionary mapping field names to formfields.
+               
+               """
+               

                raise NotImplementedError
        
        def construct_instance(self, **kwargs):
                raise NotImplementedError
        
        def construct_instance(self, **kwargs):

-               """Apply cleaned data from the formfields generated by valid_formfields to oneself."""
+               """Applies cleaned data from the formfields generated by valid_formfields to oneself."""

                raise NotImplementedError
        
        def __unicode__(self):
                raise NotImplementedError
        
        def __unicode__(self):


@@ -73,10 +93,12 @@ class AttributeValue(models.Model):
                abstract = True
 
 
                abstract = True
 
 

+#: An instance of :class:`ContentTypeSubclassLimiter` which is used to track the content types which are considered valid value models for an :class:`Attribute`.

 attribute_value_limiter = ContentTypeSubclassLimiter(AttributeValue)
 
 
 class JSONValue(AttributeValue):
 attribute_value_limiter = ContentTypeSubclassLimiter(AttributeValue)
 
 
 class JSONValue(AttributeValue):

+       """Stores a python object as a json string."""

        value = JSONField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.', default='null', db_index=True)
        
        def __unicode__(self):
        value = JSONField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.', default='null', db_index=True)
        
        def __unicode__(self):


@@ -99,6 +121,7 @@ class JSONValue(AttributeValue):
 
 
 class ForeignKeyValue(AttributeValue):
 
 
 class ForeignKeyValue(AttributeValue):

+       """Stores a generic relationship to an instance of any value content type (as defined by the :data:`value_content_type_limiter`)."""

        content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
        object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)
        value = generic.GenericForeignKey()
        content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
        object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)
        value = generic.GenericForeignKey()


@@ -136,6 +159,7 @@ class ForeignKeyValue(AttributeValue):
 
 
 class ManyToManyValue(AttributeValue):
 
 
 class ManyToManyValue(AttributeValue):

+       """Stores a generic relationship to many instances of any value content type (as defined by the :data:`value_content_type_limiter`)."""

        content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
        values = models.ManyToManyField(ForeignKeyValue, blank=True, null=True)
        
        content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
        values = models.ManyToManyField(ForeignKeyValue, blank=True, null=True)
        


@@ -215,14 +239,20 @@ class ManyToManyValue(AttributeValue):
 
 
 class Attribute(models.Model):
 
 
 class Attribute(models.Model):

+       """Represents an arbitrary key/value pair on an arbitrary :class:`Model` where the key consists of word characters and the value is a subclass of :class:`AttributeValue`."""

        entity_content_type = models.ForeignKey(ContentType, related_name='attribute_entity_set', verbose_name='Entity type')
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID', db_index=True)
        entity_content_type = models.ForeignKey(ContentType, related_name='attribute_entity_set', verbose_name='Entity type')
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID', db_index=True)

+       
+       #: :class:`GenericForeignKey` to anything (generally an instance of an Entity subclass).

        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        
        value_content_type = models.ForeignKey(ContentType, related_name='attribute_value_set', limit_choices_to=attribute_value_limiter, verbose_name='Value type', null=True, blank=True)
        value_object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        
        value_content_type = models.ForeignKey(ContentType, related_name='attribute_value_set', limit_choices_to=attribute_value_limiter, verbose_name='Value type', null=True, blank=True)
        value_object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)

+       
+       #: :class:`GenericForeignKey` to an instance of a subclass of :class:`AttributeValue` as determined by the :data:`attribute_value_limiter`.

        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        
        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        

+       #: :class:`CharField` containing a key (up to 255 characters) consisting of alphanumeric characters and underscores.

        key = models.CharField(max_length=255, validators=[RegexValidator("\w+")], help_text="Must contain one or more alphanumeric characters or underscores.", db_index=True)
        
        def __unicode__(self):
        key = models.CharField(max_length=255, validators=[RegexValidator("\w+")], help_text="Must contain one or more alphanumeric characters or underscores.", db_index=True)
        
        def __unicode__(self):


@@ -279,12 +309,26 @@ class EntityBase(models.base.ModelBase):
 
 
 class Entity(models.Model):
 
 
 class Entity(models.Model):

+       """An abstract class that simplifies access to related attributes. Most models provided by Philo subclass Entity."""

        __metaclass__ = EntityBase
        
        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        
        @property
        def attributes(self):
        __metaclass__ = EntityBase
        
        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        
        @property
        def attributes(self):

+               """
+               Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly.
+
+               Example::
+
+                       >>> attr = entity.attribute_set.get(key='spam')
+                       >>> attr.value.value
+                       u'eggs'
+                       >>> entity.attributes['spam']
+                       u'eggs'
+               
+               """
+               

                return QuerySetMapper(self.attribute_set.all())
        
        class Meta:
                return QuerySetMapper(self.attribute_set.all())
        
        class Meta:


@@ -296,19 +340,21 @@ class TreeManager(models.Manager):
        
        def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='slug'):
                """
        
        def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='slug'):
                """

-               Returns the object with the path, unless absolute_result is set to False, in which
-               case it returns a tuple containing the deepest object found along the path, and the
-               remainder of the path after that object as a string (or None if there is no remaining
-               path). Raises a DoesNotExist exception if no object is found with the given path.
-               
-               If the path you're searching for is known to exist, it is always faster to use
-               absolute_result=True - unless the path depth is over ~40, in which case the high cost
-               of the absolute query makes a binary search (i.e. non-absolute) faster.
+               If ``absolute_result`` is ``True``, returns the object at ``path`` (starting at ``root``) or raises a :class:`DoesNotExist` exception. Otherwise, returns a tuple containing the deepest object found along ``path`` (or ``root`` if no deeper object is found) and the remainder of the path after that object as a string (or None if there is no remaining path).
+               
+               .. note:: If you are looking for something with an exact path, it is faster to use absolute_result=True, unless the path depth is over ~40, in which case the high cost of the absolute query may make a binary search (i.e. non-absolute) faster.
+               
+               .. note:: SQLite allows max of 64 tables in one join. That means the binary search will only work on paths with a max depth of 127 and the absolute fetch will only work to a max depth of (surprise!) 63. Larger depths could be handled, but since the common use case will not have a tree structure that deep, they are not.
+               
+               :param path: The path of the object
+               :param root: The object which will be considered the root of the search
+               :param absolute_result: Whether to return an absolute result or do a binary search
+               :param pathsep: The path separator used in ``path``
+               :param field: The field on the model which should be queried for ``path`` segment matching.
+               :returns: An instance if absolute_result is True or (instance, remaining_path) otherwise.
+               

                """
                """

-               # Note: SQLite allows max of 64 tables in one join. That means the binary search will
-               # only work on paths with a max depth of 127 and the absolute fetch will only work
-               # to a max depth of (surprise!) 63. Although this could be handled, chances are your
-               # tree structure won't be that deep.
+               

                segments = path.split(pathsep)
                
                # Clean out blank segments. Handles multiple consecutive pathseps.
                segments = path.split(pathsep)
                
                # Clean out blank segments. Handles multiple consecutive pathseps.


@@ -407,6 +453,14 @@ class TreeModel(MPTTModel):
        slug = models.SlugField(max_length=255)
        
        def get_path(self, root=None, pathsep='/', field='slug'):
        slug = models.SlugField(max_length=255)
        
        def get_path(self, root=None, pathsep='/', field='slug'):

+               """
+               :param root: Only return the path since this object.
+               :param pathsep: The path separator to use when constructing an instance's path
+               :param field: The field to pull path information from for each ancestor.
+               :returns: A string representation of an object's path.
+               
+               """
+               

                if root == self:
                        return ''
                
                if root == self:
                        return ''
                


@@ -438,10 +492,27 @@ class TreeEntityBase(MPTTModelBase, EntityBase):
 
 
 class TreeEntity(Entity, TreeModel):
 
 
 class TreeEntity(Entity, TreeModel):

+       """An abstract subclass of Entity which represents a tree relationship."""
+       

        __metaclass__ = TreeEntityBase
        
        @property
        def attributes(self):
        __metaclass__ = TreeEntityBase
        
        @property
        def attributes(self):

+               """
+               Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly. If an attribute with a given key is not related to the :class:`Entity`, then the object will check the parent's attributes.
+
+               Example::
+
+                       >>> attr = entity.attribute_set.get(key='spam')
+                       DoesNotExist: Attribute matching query does not exist.
+                       >>> attr = entity.parent.attribute_set.get(key='spam')
+                       >>> attr.value.value
+                       u'eggs'
+                       >>> entity.attributes['spam']
+                       u'eggs'
+               
+               """
+               

                if self.parent:
                        return QuerySetMapper(self.attribute_set.all(), passthrough=self.parent.attributes)
                return super(TreeEntity, self).attributes
                if self.parent:
                        return QuerySetMapper(self.attribute_set.all(), passthrough=self.parent.attributes)
                return super(TreeEntity, self).attributes