# ============================================================================
#
# Copyright (C) 2007-2011 Conceptive Engineering bvba. All rights reserved.
# www.conceptive.be / project-camelot@conceptive.be
#
# This file is part of the Camelot Library.
#
# This file may be used under the terms of the GNU General Public
# License version 2.0 as published by the Free Software Foundation
# and appearing in the file license.txt included in the packaging of
# this file. Please review this information to ensure GNU
# General Public Licensing requirements will be met.
#
# If you are unsure which license is appropriate for your use, please
# visit www.python-camelot.com or contact project-camelot@conceptive.be
#
# This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
# WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
#
# For use of this library in commercial applications, please contact
# project-camelot@conceptive.be
#
# ============================================================================
"""Admin class for Plain Old Python Object"""
import logging
logger = logging.getLogger('camelot.view.object_admin')
from camelot.view.model_thread import gui_function, model_function
from camelot.view.controls.tableview import TableView
from camelot.core.utils import ugettext as _
from camelot.core.utils import ugettext_lazy
from camelot.view.proxy.collection_proxy import CollectionProxy
from validator.object_validator import ObjectValidator
from PyQt4 import QtCore
[docs]class FieldAttributesList(list):
"""A list with field attributes that documents them for
sphinx"""
def __init__(self, original_list):
""":param original_list: the list with field attributes
to document"""
super(FieldAttributesList, self).__init__(original_list)
template = "\n * :ref:`%s <field-attribute-%s>`"
doc = '\n'.join([template%(name, name) for name in original_list])
self.__doc__ = doc
DYNAMIC_FIELD_ATTRIBUTES = FieldAttributesList(['tooltip', 'color', 'background_color',
'editable', 'choices',
'prefix', 'suffix', 'arrow',
'new_message', 'default',
'precision'])
[docs]class ObjectAdmin(object):
"""The ObjectAdmin class describes the interface that will be used
to interact with objects of a certain class. The behaviour of this class
and the resulting interface can be tuned by specifying specific class
attributes:
**The name used in the GUI**
The name used in the GUI for things like window titles and such can
be specified using the verbose_name attribute.
.. attribute:: verbose_name
A human-readable name for the object, singular ::
verbose_name = _('movie')
If this isn't given, the class name will be used
.. attribute:: verbose_name_plural
A human-readable name for the object, plural ::
verbose_name_plural = _('movies')
If this isn't given, Camelot will use verbose_name + "s"
**Fields displayed**
.. attribute:: list_display
a list with the fields that should be displayed in a table view
.. attribute:: list_columns_frozen
the number of columns on the left of the tableview that should be frozen
(don't dissapear when the user uses the horizontal scroll bar), defaults
to zero
.. attribute:: lines_per_row
An integer number specifying the height of a row in the table view, expressed
as the number of lines of text it should be able to display. Defaults to 1.
.. attribute:: form_display
a list with the fields that should be displayed in a form view, defaults to
the same fields as those specified in list_display ::
class Admin(EntityAdmin):
form_display = ['title', 'rating', 'cover']
instead of telling which fields to display. It is also possible to define
the form itself ::
from camelot.view.forms import Form, TabForm, WidgetOnlyForm, HBoxForm
class Admin(EntityAdmin):
form_display = TabForm([
('Movie', Form([
HBoxForm([['title', 'rating'], WidgetOnlyForm('cover')]),
'short_description',
'releasedate',
'director',
'script',
'genre',
'description', 'tags'], scrollbars=True)),
('Cast', WidgetOnlyForm('cast'))
])
**Behaviour**
.. attribute:: save_mode
Specifies when the data should be send from the view to the model and flushed
to the database. The default mode is 'on_change', meaning that every change
in the view will be send immediately to the database. Other possibilities are :
* 'on_leave' : the data will be send from the view to the model when the view
is closed, eg. : the form is closed.
.. attribute:: delete_mode
Indicates if the deletion of an object should be confirmed by the user, defaults
to 'on_request', indicating object should be deleted when the user hits the trash
button. Other possibilities are :
* 'on_confirm' : the user will be asked for confirmation before the delete
takes place.
.. attribute:: form_size
a tuple indicating the size of a form view, defaults to (700,500)
.. attribute:: form_actions
Actions to be accessible by pushbuttons on the side of a form,
a list of tuples (button_label, action_function) where action_function
takes as its single argument, a method that returns the the object that
was displayed by the form when the button was pressed::
class Admin(EntityAdmin):
form_actions = [('Foo', lamda o_getter:print 'foo')]
**Field attributes**
.. attribute:: field_attributes
A dictionary specifying for each field of the model some additional
attributes on how they should be displayed. All of these attributes
are propagated to the constructor of the delegate of this field::
class Movie(Entity):
title = Field(Unicode(50))
class Admin(EntityAdmin):
list_display = ['title']
field_attributes = dict(title=dict(editable=False))
The :ref:`doc-admin-field_attributes` documentation describes the various keys
that can be used in the field attributes class attribute of an ObjectAdmin
or EntityAdmin.
**Window state**
.. attribute:: form_state
Set this attribute to 'maximized' or 'minimized' for respective behaviour. These are the only two defined at the moment.
Please use the constants defined in camelot.core.constants (MINIMIZE and MAXIMIZE).
Note that this attr needs to be set at the form, highest in the form hierarchy to work. Setting this on embedded forms
will not influence the window state. Example::
class Movie(Entity):
title = Field(Unicode(50))
class Admin(EntityAdmin):
from camelot.core import constants
list_display = ['title']
form_state = constants.MAXIMIZED
field_attributes = dict(title=dict(editable=False))
**Varia**
.. attribute:: model
The QAbstractItemModel class to be used to display collections of this object,
defaults to a CollectionProxy
.. attribute:: TableView
The QWidget class to be used when a table view is needed
"""
verbose_name = None
verbose_name_plural = None
list_display = []
list_columns_frozen = 0
lines_per_row = 1
validator = ObjectValidator
model = CollectionProxy
fields = []
form_display = []
list_filter = []
list_charts = []
list_actions = []
list_size = (600, 400)
form_size = (700, 500)
form_actions = []
field_attributes = {}
form_state = None
icon = None # Default
#
# Behavioral attributes
#
save_mode = 'on_edit'
delete_mode = 'on_request'
TableView = TableView
def __init__(self, app_admin, entity):
"""
:param app_admin: the application admin object for this application,
if None, then the default application_admin is taken
:param entity: the entity class for which this admin instance is to be
used
"""
from camelot.view.remote_signals import get_signal_handler
if not app_admin:
from camelot.admin.application_admin import get_application_admin
self.app_admin = get_application_admin()
else:
self.app_admin = app_admin
self.rsh = get_signal_handler()
if entity:
from camelot.view.model_thread import get_model_thread
self.entity = entity
self.mt = get_model_thread()
#
# caches to prevent recalculation of things
#
self._field_attributes = dict()
self._subclasses = None
def __str__(self):
return 'Admin %s' % str(self.entity.__name__)
def __repr__(self):
return 'ObjectAdmin(%s)' % str(self.entity.__name__)
[docs] def get_name(self):
return self.get_verbose_name()
[docs] def get_verbose_name(self):
# def uncamelize(text):
# def downcase(matchobj):
# return "_" + matchobj.group(0).lower()
# if text:
# text = text[0].lower() + re.sub(r'([A-Z])', downcase, text[1:])
# return text
return unicode(
self.verbose_name or _(self.entity.__name__.capitalize())
)
[docs] def get_verbose_name_plural(self):
return unicode(
self.verbose_name_plural
or (self.get_verbose_name() + 's')
)
[docs] def get_icon(self):
return self.icon
@model_function
[docs] def get_verbose_identifier(self, obj):
"""Create an identifier for an object that is interpretable
for the user, eg : the primary key of an object. This verbose identifier can
be used to generate a title for a form view of an object.
"""
return u'%s : %s' % (self.get_verbose_name(), unicode(obj))
[docs] def get_entity_admin(self, entity):
return self.app_admin.get_entity_admin(entity)
[docs] def get_save_mode(self):
return self.save_mode
[docs] def get_delete_mode(self):
return self.delete_mode
[docs] def get_delete_message(self, obj):
return _('Are you sure you want to delete this')
@model_function
@model_function
[docs] def get_list_actions(self):
return self.list_actions
@model_function
[docs] def get_depending_objects(self, obj):
"""Overwrite this function to generate a list of objects that depend on a given
object. When obj is modified by the user, this function will be called to determine
which other objects need their views updated.
:param obj: an object of the type that is managed by this admin class
:return: an iterator over objects that depend on obj
"""
return []
@model_function
[docs] def get_subclass_tree( self ):
"""Get a tree of admin classes representing the subclasses of the class
represented by this admin class
:return: [(subclass_admin, [(subsubclass_admin, [...]),...]),...]
"""
subclasses = []
for subclass in self.entity.__subclasses__():
subclass_admin = self.get_related_entity_admin(subclass)
if subclass_admin!=self:
subclasses.append((
subclass_admin,
subclass_admin.get_subclass_tree()
))
def sort_admins(a1, a2):
return cmp(a1[0].get_verbose_name_plural(), a2[0].get_verbose_name_plural())
subclasses.sort(cmp=sort_admins)
return subclasses
[docs] def get_static_field_attributes(self, field_names):
"""
Convenience function to get all the field attributes
that are static (don't depend on the object being visualized). This
method is only called once for a table or form view, independent of
the number of objects/records being visualized.
:param field_names: a list of field names
:return: [{field_attribute_name:field_attribute_value, ...}, {}, ...]
The returned list has the same order than the requested
field_names.
"""
for field_name in field_names:
field_attributes = self.get_field_attributes(field_name)
static_field_attributes = {}
for name, value in field_attributes.items():
if name not in DYNAMIC_FIELD_ATTRIBUTES or not callable(value):
static_field_attributes[name] = value
yield static_field_attributes
[docs] def get_dynamic_field_attributes(self, obj, field_names):
"""
Convenience function to get all the field attributes
that are dynamic (depend on the object being visualized). This method
is called once for each object/row in a table view and once for
each object being visualized in a form view.
:param field_names: a list of field names
:param obj: the object at the row for which to get the values of the dynamic field attributes
:return: [{field_attribute_name:field_attribute_value, ...}, {}, ...]
The returned list has the same order than the requested
field_names.
"""
for field_name in field_names:
field_attributes = self.get_field_attributes(field_name)
dynamic_field_attributes = {}
for name, value in field_attributes.items():
if name not in DYNAMIC_FIELD_ATTRIBUTES:
continue
if callable(value):
return_value = None
try:
return_value = value(obj)
except (ValueError, Exception, RuntimeError, TypeError, NameError), exc:
logger.error(u'error in field_attribute function of %s'%name, exc_info=exc)
finally:
dynamic_field_attributes[name] = return_value
yield dynamic_field_attributes
[docs] def get_field_attributes(self, field_name):
"""
Get the attributes needed to visualize the field field_name. This
function is called by get_static_field_attributes and
get_dynamic_field_attributes.
This function first tries to fill the dictionary with field
attributes for a field with those gathered through introspection,
and then updates them with those found in the field_attributes
class attribute.
:param field_name: the name of the field
:return: a dictionary of attributes needed to visualize the field
The values of the returned dictionary either contain the value
of the field attribute, or in the case of dynamic field attributes,
a function that returns the value of the field attribute.
"""
try:
return self._field_attributes[field_name]
except KeyError:
def create_default_getter(field_name):
return lambda o:getattr(o, field_name)
from camelot.view.controls import delegates
#
# Default attributes for all fields
#
attributes = dict(
getter=create_default_getter(field_name),
field_name=field_name,
python_type=str,
length=None,
tooltip=None,
background_color=None,
minimal_column_width=12,
editable=False,
nullable=True,
widget='str',
blank=True,
delegate=delegates.PlainTextDelegate,
validator_list=[],
name=ugettext_lazy(field_name.replace( '_', ' ' ).capitalize())
)
#
# Field attributes forced by the field_attributes property
#
forced_attributes = {}
try:
forced_attributes = self.field_attributes[field_name]
except KeyError:
pass
#
# TODO : move part of logic from entity admin class over here
#
#
# Overrule introspected field_attributes with those defined
#
attributes.update(forced_attributes)
#
# In case of a 'target' field attribute, instantiate an appropriate
# 'admin' attribute
#
def get_entity_admin(target):
"""Helper function that instantiated an Admin object for a
target entity class
:param target: an entity class for which an Admin object is
needed
"""
try:
fa = self.field_attributes[field_name]
target = fa.get('target', target)
admin_class = fa['admin']
return admin_class(self.app_admin, target)
except KeyError:
return self.get_related_entity_admin(target)
if 'target' in attributes:
attributes['admin'] = get_entity_admin(attributes['target'])
self._field_attributes[field_name] = attributes
return attributes
@model_function
[docs] def get_columns(self):
"""
The columns to be displayed in the list view, returns a list of pairs
of the name of the field and its attributes needed to display it
properly
@return: [(field_name,
{'widget': widget_type,
'editable': True or False,
'blank': True or False,
'validator_list':[...],
'name':'Field name'}),
...]
"""
return [(field, self.get_field_attributes(field))
for field in self.list_display]
[docs] def create_validator(self, model):
return self.validator(self, model)
@model_function
[docs] def get_fields(self):
if self.form_display:
fields = self.get_form_display().get_fields()
elif self.fields:
fields = self.fields
else:
fields = self.list_display
fields_and_attributes = [
(field, self.get_field_attributes(field))
for field in fields
]
return fields_and_attributes
@model_function
[docs] def get_all_fields_and_attributes(self):
"""A dictionary of (field_name:field_attributes) for all fields that can
possibly appear in a list or a form or for which field attributes have
been defined
"""
fields = dict(self.get_columns())
fields.update(dict(self.get_fields()))
return fields
@model_function
def _apply_form_state(self, widget):
"""apply the consequences of the form_state class attribute
to a widget"""
if hasattr(self, 'form_state'):
from camelot.core import constants
if self.form_state == constants.MAXIMIZED:
widget.setWindowState(QtCore.Qt.WindowMaximized)
if self.form_state == constants.MINIMIZED:
widget.setWindowState(QtCore.Qt.WindowMinimized)
@gui_function
[docs] def set_defaults(self, object_instance, include_nullable_fields=True):
"""Set the defaults of an object
:param include_nullable_fields: also set defaults for nullable fields, depending
on the context, this should be set to False to allow the user to set the field
to None
"""
from sqlalchemy.schema import ColumnDefault
for field, attributes in self.get_fields():
has_default = False
try:
default = attributes['default']
has_default = True
except KeyError:
pass
if has_default:
#
# prevent the setting of a default value when one has been
# set already
#
value = attributes['getter'](object_instance)
if value!=None: # False is a legitimate value for Booleans
continue
if isinstance(default, ColumnDefault):
default_value = default.execute()
elif callable(default):
import inspect
args, _varargs, _kwargs, _defs = \
inspect.getargspec(default)
if len(args):
default_value = default(object_instance)
else:
default_value = default()
else:
default_value = default
logger.debug(
'set default for %s to %s' % (
field,
unicode(default_value)
)
)
try:
setattr(object_instance, field, default_value)
except AttributeError, exc:
logger.error(
'Programming Error : could not set'
' attribute %s to %s on %s' % (
field,
default_value,
object_instance.__class__.__name__
),
exc_info=exc
)
@gui_function
@gui_function
[docs] def create_new_view(admin, related_collection_proxy=None, parent=None):
"""Create a Qt widget containing a form to create a new instance of the
entity related to this admin class
The returned class has an 'entity_created_signal' that will be fired
when a valid new entity was created by the form
:param collection_proxy: if specified, the object will be appended to
its underlying collection upon creation and removed from it upon
discarding.
"""
from PyQt4 import QtGui, QtCore
from camelot.view.controls.view import AbstractView
from camelot.view.model_thread import post
class NewObjectCollectionProxy( CollectionProxy ):
"""A CollectionProxy for creating new objects, the underlying collection
will always be filled with a single object."""
def __init__(self, related_collection_proxy, *args, **kwargs):
# set attributes before initializing NewObjectCollectionProxy,
# because this one contains posts that need these attributes
self._new_object = None
self._related_collection_proxy = related_collection_proxy
super(NewObjectCollectionProxy, self).__init__(*args, **kwargs)
@property
def max_number_of_rows(self):
return 1
def get_new_object(self):
if not self._new_object:
self._new_object = admin.entity()
# Give the default fields their value
admin.set_defaults(self._new_object)
if self._related_collection_proxy:
self._related_collection_proxy.append_object( self._new_object )
return self._new_object
def get_collection(self):
return [self.get_new_object()]
def _expunge_new_object(self):
if self._new_object:
admin.expunge( self._new_object )
if self._related_collection_proxy:
self._related_collection_proxy.remove_objects( [self._new_object],
delete = False )
def expunge(self):
"""Discontinue the creation of the new object, expunge it
from its session and the related_collection proxy"""
post( self._expunge_new_object )
model = NewObjectCollectionProxy( related_collection_proxy,
admin,
None,
admin.get_fields,
max_number_of_rows=1 )
validator = admin.create_validator(model)
class NewForm(AbstractView):
entity_created_signal = QtCore.pyqtSignal(object)
def __init__(self, parent):
AbstractView.__init__(self, parent)
self.widget_layout = QtGui.QVBoxLayout()
self.widget_layout.setContentsMargins(0, 0, 0, 0)
title = _('New')
index = 0
self.form_view = admin.create_form_view(
title, model, index, parent
)
self.widget_layout.insertWidget(0, self.form_view)
self.setLayout(self.widget_layout)
self.validate_before_close = True
#
# every time data has been changed, it could become valid,
# when this is the case, it should be propagated
#
model.dataChanged.connect( self.dataChanged )
self.form_view.title_changed_signal.connect( self.change_title )
def emit_if_valid(self, valid):
if valid:
def create_instance_getter(new_object):
return lambda:new_object[0]
self.entity_created_signal.emit( model.get_new_object )
@QtCore.pyqtSlot( QtCore.QModelIndex, QtCore.QModelIndex )
def dataChanged(self, _index1, _index2):
def validate():
return validator.isValid(0)
post(validate, self.emit_if_valid)
def showMessage(self, valid):
self.emit_if_valid(valid)
form = self.form_view.findChild(QtGui.QWidget, 'form' )
if not valid and form:
row = 0
reply = validator.validityDialog(row, self).exec_()
if reply == QtGui.QMessageBox.Discard:
# clear mapping to prevent data being written again to
# the model, after we reverted the row
form.clear_mapping()
model.expunge()
self.validate_before_close = False
self.close()
else:
self.validate_before_close = False
self.close()
def validateClose(self):
logger.debug(
'validate before close : %s' %
self.validate_before_close
)
form = self.form_view.findChild(QtGui.QWidget, 'form' )
if self.validate_before_close:
form.submit()
logger.debug(
'unflushed rows : %s' %
str(model.hasUnflushedRows())
)
if model.hasUnflushedRows():
def validate_and_flush():
valid = validator.isValid(0)
if valid:
admin.flush( model.get_new_object() )
return valid
post(validate_and_flush, self.showMessage)
return False
else:
return True
return True
def closeEvent(self, event):
if self.validateClose():
event.accept()
else:
event.ignore()
form = NewForm(parent)
admin._apply_form_state( form )
if hasattr(admin, 'form_size'):
form.setMinimumSize(admin.form_size[0], admin.form_size[1])
return form
@model_function
[docs] def delete(self, entity_instance):
"""Delete an entity instance"""
del entity_instance
@model_function
[docs] def flush(self, entity_instance):
"""Flush the pending changes of this entity instance to the backend"""
pass
@model_function
[docs] def expunge(self, entity_instance):
"""Remove this object from the objects being managed"""
pass
@model_function
[docs] def refresh(self, entity_instance):
"""Undo the pending changes to the backend and restore the original
state"""
pass
@model_function
[docs] def add(self, entity_instance):
"""Add an entity instance as a managed entity instance"""
pass
@model_function
[docs] def is_deleted(self, _obj):
"""
:return: True if the object has been deleted from the persistent
state, False otherwise"""
return False
@model_function
[docs] def is_persistent(self, _obj):
""":return: True if the object has a persisted state, False otherwise"""
return False
@model_function
[docs] def copy(self, entity_instance):
"""Duplicate this entity instance"""
new_entity_instance = entity_instance.__class__()
return new_entity_instance