def swap_html_model(swap):
"""
Temporary fix to swap HTML model for Div model during png export
to avoid issues with DOMParser compatibility in PhantomJS.
Can be removed when switching to chromedriver.
"""
from ..viewable import Viewable
state._html_escape = False
swapped = []
for viewable in param.concrete_descendents(Viewable).values():
model = getattr(viewable, '_bokeh_model', None)
try:
swap_model = issubclass(model, HTML) and swap
assert swap_model
except Exception:
continue
else:
viewable._bokeh_model = Div
swapped.append(viewable)
try:
yield
finally:
state._html_escape = True
for viewable in swapped:
viewable._bokeh_model = HTML
def _apply_signatures(self):
from inspect import Parameter, Signature
from .viewable import Viewable
descendants = param.concrete_descendents(Viewable)
for cls in reversed(list(descendants.values())):
if cls.__doc__.startswith('params'):
prefix = cls.__doc__.split('\n')[0]
cls.__doc__ = cls.__doc__.replace(prefix, '')
sig = inspect.signature(cls.__init__)
sig_params = list(sig.parameters.values())
if not sig_params or sig_params[-1] != Parameter(
'params', Parameter.VAR_KEYWORD):
continue
parameters = sig_params[:-1]
processed_kws, keyword_groups = set(), []
for cls in reversed(cls.mro()):
keyword_group = []
for (k, v) in sorted(cls.__dict__.items()):
if (isinstance(v, param.Parameter)
and k not in processed_kws and not v.readonly):
keyword_group.append(k)
processed_kws.add(k)
keyword_groups.append(keyword_group)
parameters += [
Parameter(name, Parameter.KEYWORD_ONLY)
for kws in reversed(keyword_groups) for name in kws
if name not in sig.parameters
]
kwarg_name = '_kwargs' if 'kwargs' in processed_kws else 'kwargs'
parameters.append(Parameter(kwarg_name, Parameter.VAR_KEYWORD))
cls.__init__.__signature__ = Signature(
parameters, return_annotation=sig.return_annotation)
def css_files(self):
from ..config import config
from ..reactive import ReactiveHTML
files = super(Resources, self).css_files
for model in param.concrete_descendents(ReactiveHTML).values():
if hasattr(model, '__css__'):
for css_file in model.__css__:
if css_file not in files:
files.append(css_file)
for cssf in config.css_files:
if os.path.isfile(cssf) or cssf in files:
continue
files.append(cssf)
if self.mode == 'server':
if state.rel_path:
dist_dir = f'{state.rel_path}/{LOCAL_DIST}'
else:
dist_dir = LOCAL_DIST
else:
dist_dir = CDN_DIST
for cssf in glob.glob(str(DIST_DIR / 'css' / '*.css')):
if self.mode == 'inline':
break
files.append(dist_dir + f'css/{os.path.basename(cssf)}')
return files
def get_pane_type(cls, obj):
"""
Returns the applicable Pane type given an object by resolving
the precedence of all types whose applies method declares that
the object is supported.
Arguments
---------
obj (object): The object type to return a Pane for
Returns
-------
The applicable Pane type with the highest precedence.
"""
if isinstance(obj, Viewable):
return type(obj)
descendents = []
for p in param.concrete_descendents(PaneBase).values():
priority = p.applies(obj) if p.priority is None else p.priority
if isinstance(priority, bool) and priority:
raise ValueError('If a Pane declares no priority '
'the applies method should return a '
'priority value specific to the '
'object type or False, but the %s pane '
'declares no priority.' % p.__name__)
elif priority is None or priority is False:
continue
descendents.append((priority, p))
pane_types = reversed(sorted(descendents, key=lambda x: x[0]))
for _, pane_type in pane_types:
applies = pane_type.applies(obj)
if isinstance(applies, bool) and not applies: continue
return pane_type
raise TypeError('%s type could not be rendered.' % type(obj).__name__)
def __init__(self, **params):
super(StepFilter, self).__init__(**params)
self.filter_type = self.previousFilterType = None
self.param['filterTypeSelector'].objects = [view for view in param.concrete_descendents(Filter).values() if
view in filterTypeSupported]
self.param['filterTypeSelector'].default = self.param['filterTypeSelector'].objects[0]
self.dashboard = Dashboard(specification=r'specYamlFile/default/nouveau_dashboard_default_config.yml')
self.filterTypeParametersDynamicWidgetsSelector = None
def bundle_resources():
from .config import panel_extension
from .template.base import BasicTemplate
for imp in panel_extension._imports.values():
if imp.startswith('panel.'):
__import__(imp)
bundle_dir = pathlib.Path(__file__).parent.joinpath('dist', 'bundled')
js_files = {}
css_files = {}
for name, model in Model.model_class_reverse_map.items():
if not name.startswith('panel.'):
continue
prev_jsfiles = getattr(model, '__javascript_raw__', None)
prev_jsbundle = getattr(model, '__tarball__', None)
prev_cls = model
for cls in model.__mro__[1:]:
jsfiles = getattr(cls, '__javascript_raw__', None)
if ((jsfiles is None and prev_jsfiles is not None)
or (jsfiles is not None and jsfiles != prev_jsfiles)):
if prev_jsbundle:
js_files[prev_cls.__name__] = prev_jsbundle
else:
js_files[prev_cls.__name__] = prev_jsfiles
break
prev_cls = cls
prev_cssfiles = getattr(model, '__css_raw__', None)
prev_cls = model
for cls in model.__mro__[1:]:
cssfiles = getattr(cls, '__css_raw__', None)
if ((cssfiles is None and prev_cssfiles is not None)
or (cssfiles is not None and cssfiles != prev_cssfiles)):
css_files[prev_cls.__name__] = prev_cssfiles
break
prev_cls = cls
for name, jsfiles in js_files.items():
if isinstance(jsfiles, dict):
write_bundled_tarball(name, jsfiles, bundle_dir)
else:
write_bundled_files(name, jsfiles, bundle_dir)
for name, cssfiles in css_files.items():
write_bundled_files(name, cssfiles, bundle_dir)
# Bundle external template dependencies
for name, template in param.concrete_descendents(BasicTemplate).items():
write_bundled_files(name, list(template._resources['css'].values()),
bundle_dir)
write_bundled_files(name, list(template._resources['js'].values()),
bundle_dir)
template_dir = pathlib.Path(inspect.getfile(template)).parent
dest_dir = bundle_dir / name.lower()
dest_dir.mkdir(parents=True, exist_ok=True)
for css in glob.glob(str(template_dir / '*.css')):
shutil.copyfile(css, dest_dir / os.path.basename(css))
def _coerce(self, dataset):
if self.interface_applies(dataset, coerce=False):
return dataset
pandas_interfaces = param.concrete_descendents(PandasInterface)
datatypes = [
intfc.datatype for intfc in pandas_interfaces.values()
if dataset.interface.multi == intfc.multi
]
return dataset.clone(datatype=datatypes)
def _get_type(cls, filter_type):
try:
__import__(f'lumen.filters.{filter_type}')
except Exception:
pass
for filt in param.concrete_descendents(cls).values():
if filt.filter_type == filter_type:
return filt
raise ValueError(f"No Filter for filter_type '{filter_type}' could be found.")
def require_components():
"""
Returns JS snippet to load the required dependencies in the classic
notebook using REQUIRE JS.
"""
from .config import config
from .reactive import ReactiveHTML
configs, requirements, exports = [], [], {}
js_requires = []
from bokeh.model import Model
for qual_name, model in Model.model_class_reverse_map.items():
# We need to enable Models from Panel as well as Panel extensions
# like awesome_panel_extensions.
# The Bokeh models do not have "." in the qual_name
if "." in qual_name:
js_requires.append(model)
js_requires += list(param.concrete_descendents(ReactiveHTML).values())
for export, js in config.js_files.items():
name = js.split('/')[-1].replace('.min', '').split('.')[-2]
conf = {'paths': {name: js[:-3]}, 'exports': {name: export}}
js_requires.append(conf)
skip_import = {}
for model in js_requires:
if hasattr(model, '__js_skip__'):
skip_import.update(model.__js_skip__)
if not (hasattr(model, '__js_require__') or isinstance(model, dict)):
continue
if isinstance(model, dict):
model_require = model
else:
model_require = dict(model.__js_require__)
model_exports = model_require.pop('exports', {})
if not any(model_require == config for config in configs):
configs.append(model_require)
for req in list(model_require.get('paths', [])):
if isinstance(req, tuple):
model_require['paths'] = dict(model_require['paths'])
model_require['paths'][req[0]] = model_require['paths'].pop(req)
reqs = req[1] if isinstance(req, tuple) else (req,)
for r in reqs:
if r not in requirements:
requirements.append(r)
if r in model_exports:
exports[r] = model_exports[r]
return configs, requirements, exports, skip_import
def get_pane_type(cls, obj):
if isinstance(obj, Viewable):
return type(obj)
descendents = [(p.precedence, p)
for p in param.concrete_descendents(PaneBase).values()]
pane_types = reversed(sorted(descendents, key=lambda x: x[0]))
for _, pane_type in pane_types:
if not pane_type.applies(obj): continue
return pane_type
raise TypeError('%s type could not be rendered.' % type(obj).__name__)
def _get_type(cls, source_type):
try:
__import__(f'lumen.sources.{source_type}')
except Exception:
pass
for source in param.concrete_descendents(cls).values():
if source.source_type == source_type:
return source
raise ValueError(
f"No Source for source_type '{source_type}' could be found.")
def test_empty_element_constructor(self):
failed_elements = []
for name, el in param.concrete_descendents(Element).items():
if issubclass(el, (Annotation, BaseShape, Div, Tiles)):
continue
try:
el([])
except:
failed_elements.append(name)
self.assertEqual(failed_elements, [])
def test_empty_element_constructor(self):
failed_elements = []
for name, el in param.concrete_descendents(Element).items():
if issubclass(el, (Annotation, BaseShape, Div, Tiles, Trisurface)):
continue
try:
el([])
except:
failed_elements.append(name)
self.assertEqual(failed_elements, [])
def js_modules(self):
from ..config import config
from ..reactive import ReactiveHTML
modules = list(config.js_modules.values())
for model in param.concrete_descendents(ReactiveHTML).values():
if hasattr(model, '__javascript_modules__'):
for jsmodule in model.__javascript_modules__:
if jsmodule not in modules:
modules.append(jsmodule)
return modules
def test_all_linked_stream_parameters_owners():
"Test to ensure operations can accept parameters in streams dictionary"
stream_classes = param.concrete_descendents(LinkedStream)
for stream_class in stream_classes.values():
for name, p in stream_class.param.params().items():
if name != 'name' and (p.owner != stream_class):
msg = ("Linked stream %r has parameter %r which is "
"inherited from %s. Parameter needs to be redeclared "
"in the class definition of this linked stream.")
raise Exception(msg % (stream_class, name, p.owner))
def __init__(self, **kwargs):
from ..config import config
from ..reactive import ReactiveHTML
js_modules = list(config.js_modules.values())
for model in param.concrete_descendents(ReactiveHTML).values():
if hasattr(model, '__javascript_modules__'):
for js_module in model.__javascript_modules__:
if js_module not in js_modules:
js_modules.append(js_module)
self.js_modules = kwargs.pop("js_modules", js_modules)
super().__init__(**kwargs)
def find_autolinkable():
try:
import holoviews as hv
import param
except ImportError:
print('no holoviews and/or param: skipping autolinks')
return {}
# Class names for auto-linking
excluded_names = { 'UniformNdMapping', 'NdMapping', 'MultiDimensionalMapping',
'Empty', 'CompositeOverlay', 'Collator', 'AdjointLayout'}
dimensioned = set(param.concrete_descendents(hv.core.Dimensioned).keys())
all_elements = set(param.concrete_descendents(hv.Element).keys())
all_streams = set(param.concrete_descendents(hv.streams.Stream).keys())
all_containers = set((dimensioned - all_elements) - excluded_names)
return {'elements': filter_available(all_elements, 'elements'),
'streams': filter_available(all_streams, 'streams'),
'containers': filter_available(all_containers, 'containers')}
def setUp(self):
self.previous_backend = Store.current_backend
self.comm_manager = bokeh_renderer.comm_manager
bokeh_renderer.comm_manager = comms.CommManager
if not bokeh_renderer:
raise SkipTest("Bokeh required to test plot instantiation")
Store.current_backend = 'bokeh'
self._padding = {}
for plot in concrete_descendents(ElementPlot).values():
self._padding[plot] = plot.padding
plot.padding = 0
def setUp(self):
self.previous_backend = Store.current_backend
self.comm_manager = mpl_renderer.comm_manager
mpl_renderer.comm_manager = comms.CommManager
if not mpl_renderer:
raise SkipTest("Matplotlib required to test plot instantiation")
Store.set_current_backend('matplotlib')
self._padding = {}
for plot in concrete_descendents(ElementPlot).values():
self._padding[plot] = plot.padding
plot.padding = 0
def _get_type(cls, transform_type):
if '.' in transform_type:
return resolve_module_reference(transform_type, Transform)
try:
__import__(f'lumen.transforms.{transform_type}')
except Exception:
pass
for transform in param.concrete_descendents(cls).values():
if transform.transform_type == transform_type:
return transform
raise ValueError(f"No Transform for transform_type '{transform_type}' could be found.")
def _load_local_modules(self):
for imp in ('filters', 'sources', 'transforms', 'template', 'views'):
path = os.path.join(self._root, imp + '.py')
if not os.path.isfile(path):
continue
spec = importlib.util.spec_from_file_location(
f"local_lumen.{imp}", path)
self._modules[imp] = module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
templates = param.concrete_descendents(BasicTemplate)
_TEMPLATES.update({k[:-8].lower(): v for k, v in templates.items()})
def __new__(mcs, name, bases, dict_):
def add_test(p):
def test(self):
# instantiate parameter with no default (but supply
# any required args)
p(*positional_args.get(p,tuple()))
return test
for p_name, p_type in concrete_descendents(Parameter).items():
dict_["test_default_of_%s"%p_name] = add_test(p_type)
return type.__new__(mcs, name, bases, dict_)
def __init__(self, **params):
super(StepTransform, self).__init__(**params)
self.transformTypeParametersDynamicWidgetsSelector = self.transform_type = self.previousTransformType = None
self.param['transformTypeSelector'].objects = [
transform
for transform in param.concrete_descendents(Transform).values()
if transform in transformTypeSupported
]
self.param['transformTypeSelector'].default = self.param[
'transformTypeSelector'].objects[0]
self.dashboard = Dashboard(
specification=
r'specYamlFile/default/nouveau_dashboard_default_config.yml')
def extra_resources(self, resources, resource_type):
"""
Adds resources for ReactiveHTML components.
"""
from ..reactive import ReactiveHTML
for model in param.concrete_descendents(ReactiveHTML).values():
if not (getattr(model, resource_type, None) and model._loaded()):
continue
for resource in getattr(model, resource_type, []):
if not isurl(resource) and not resource.startswith(
'static/extensions'):
resource = component_resource_path(model, resource_type,
resource)
if resource not in resources:
resources.append(resource)
def _get_type(cls, view_type):
"""
Returns the matching View type.
"""
if '.' in view_type:
return resolve_module_reference(view_type, View)
try:
__import__(f'lumen.views.{view_type}')
except Exception:
pass
for view in param.concrete_descendents(cls).values():
if view.view_type == view_type:
return view
if view_type is not None:
raise ValueError(f"View type '{view_type}' could not be found.")
return View
def __new__(mcs, name, bases, dict_):
def test_skip(*args,**kw):
from nose.exc import SkipTest
raise SkipTest
def add_test(p):
def test(self):
# instantiate parameter with no default (but supply
# any required args)
p(*positional_args.get(p,tuple()))
return test
for p_name, p_type in concrete_descendents(Parameter).items():
dict_["test_default_of_%s"%p_name] = add_test(p_type) if p_name not in skip else test_skip
return type.__new__(mcs, name, bases, dict_)
def js_files(self):
from ..config import config
from ..reactive import ReactiveHTML
files = super(Resources, self).js_files
for model in param.concrete_descendents(ReactiveHTML).values():
if hasattr(model, '__javascript__'):
for jsfile in model.__javascript__:
if jsfile not in files:
files.append(jsfile)
js_files = []
for js_file in files:
if (js_file.startswith(state.base_url)
or js_file.startswith('static/')):
if js_file.startswith(state.base_url):
js_file = js_file[len(state.base_url):]
if state.rel_path:
js_file = f'{state.rel_path}/{js_file}'
js_files.append(js_file)
js_files += list(config.js_files.values())
# Load requirejs last to avoid interfering with other libraries
require_index = [
i for i, jsf in enumerate(js_files) if 'require' in jsf
]
if self.mode == 'server':
if state.rel_path:
dist_dir = f'{state.rel_path}/{LOCAL_DIST}'
else:
dist_dir = LOCAL_DIST
else:
dist_dir = CDN_DIST
if require_index:
requirejs = js_files.pop(require_index[0])
if any('ace' in jsf for jsf in js_files):
js_files.append(dist_dir + 'pre_require.js')
js_files.append(requirejs)
if any('ace' in jsf for jsf in js_files):
js_files.append(dist_dir + 'post_require.js')
return js_files
def get_pane_type(cls, obj):
if isinstance(obj, Viewable):
return type(obj)
descendents = []
for p in param.concrete_descendents(PaneBase).values():
precedence = p.applies(
obj) if p.precedence is None else p.precedence
if isinstance(precedence, bool) and precedence:
raise ValueError('If a Pane declares no precedence '
'the applies method should return a '
'precedence value specific to the '
'object type or False, but the %s pane '
'declares no precedence.' % p.__name__)
elif precedence is None or precedence is False:
continue
descendents.append((precedence, p))
pane_types = reversed(sorted(descendents, key=lambda x: x[0]))
for _, pane_type in pane_types:
applies = pane_type.applies(obj)
if isinstance(applies, bool) and not applies: continue
return pane_type
raise TypeError('%s type could not be rendered.' % type(obj).__name__)
def bundle_resources():
from .config import panel_extension
from .template.base import BasicTemplate
from .template.theme import Theme
for imp in panel_extension._imports.values():
if imp.startswith('panel.'):
__import__(imp)
bundle_dir = pathlib.Path(__file__).parent.joinpath('dist', 'bundled')
js_files = {}
css_files = {}
for name, model in Model.model_class_reverse_map.items():
if not name.startswith('panel.'):
continue
prev_jsfiles = getattr(model, '__javascript_raw__', None)
prev_jsbundle = getattr(model, '__tarball__', None)
prev_cls = model
for cls in model.__mro__[1:]:
jsfiles = getattr(cls, '__javascript_raw__', None)
if ((jsfiles is None and prev_jsfiles is not None)
or (jsfiles is not None and jsfiles != prev_jsfiles)):
if prev_jsbundle:
js_files[prev_cls.__name__] = prev_jsbundle
else:
js_files[prev_cls.__name__] = prev_jsfiles
break
prev_cls = cls
prev_cssfiles = getattr(model, '__css_raw__', None)
prev_cls = model
for cls in model.__mro__[1:]:
cssfiles = getattr(cls, '__css_raw__', None)
if ((cssfiles is None and prev_cssfiles is not None)
or (cssfiles is not None and cssfiles != prev_cssfiles)):
css_files[prev_cls.__name__] = prev_cssfiles
break
prev_cls = cls
for name, jsfiles in js_files.items():
if isinstance(jsfiles, dict):
write_bundled_tarball(name, jsfiles, bundle_dir)
else:
write_bundled_files(name, jsfiles, bundle_dir)
for name, cssfiles in css_files.items():
write_bundled_files(name, cssfiles, bundle_dir)
# Bundle external template dependencies
for name, template in param.concrete_descendents(BasicTemplate).items():
if template._resources.get('bundle', True):
write_bundled_files(
name, list(template._resources.get('css', {}).values()),
bundle_dir, 'css')
write_bundled_files(
name, list(template._resources.get('js', {}).values()),
bundle_dir, 'js')
js_modules = []
for tar_name, js_module in template._resources.get(
'js_modules', {}).items():
if tar_name not in template._resources.get('tarball', {}):
js_modules.append(js_module)
write_bundled_files(name, js_modules, bundle_dir, 'js', ext='mjs')
for tarball in template._resources.get('tarball', {}).values():
write_bundled_tarball('js', tarball, bundle_dir, module=True)
template_dir = pathlib.Path(inspect.getfile(template)).parent
dest_dir = bundle_dir / name.lower()
dest_dir.mkdir(parents=True, exist_ok=True)
for css in glob.glob(str(template_dir / '*.css')):
shutil.copyfile(css, dest_dir / os.path.basename(css))
template_css = template._css
if not isinstance(template_css, list):
template_css = [template_css] if template_css else []
for css in template_css:
tmpl_name = name
for cls in template.__mro__[2:-5]:
tmpl_css = cls._css if isinstance(cls._css,
list) else [cls._css]
if css in tmpl_css:
tmpl_name = cls.__name__.lower()
tmpl_dest_dir = bundle_dir / tmpl_name
tmpl_dest_dir.mkdir(parents=True, exist_ok=True)
shutil.copyfile(css, tmpl_dest_dir / os.path.basename(css))
if template._js:
shutil.copyfile(template._js,
dest_dir / os.path.basename(template._js))
# Bundle base themes
dest_dir = bundle_dir / 'theme'
theme_dir = pathlib.Path(inspect.getfile(Theme)).parent
dest_dir.mkdir(parents=True, exist_ok=True)
for css in glob.glob(str(theme_dir / '*.css')):
shutil.copyfile(css, dest_dir / os.path.basename(css))
# Bundle Theme classes
for name, theme in param.concrete_descendents(Theme).items():
if theme.base_css:
theme_bundle_dir = bundle_dir / theme.param.base_css.owner.__name__.lower(
)
theme_bundle_dir.mkdir(parents=True, exist_ok=True)
shutil.copyfile(
theme.base_css,
theme_bundle_dir / os.path.basename(theme.base_css))
if theme.css:
tmplt_bundle_dir = bundle_dir / theme._template.__name__.lower()
tmplt_bundle_dir.mkdir(parents=True, exist_ok=True)
shutil.copyfile(theme.css,
tmplt_bundle_dir / os.path.basename(theme.css))
assert len(widget._models) == 2
assert len(row._models) == 2
assert len(row[0]._models) == 2
assert len(row[1]._models) == 2
for cb in document.session_destroyed_callbacks:
cb(session_context)
assert len(widget._models) == 0
assert len(row._models) == 0
assert len(row[0]._models) == 0
assert len(row[1]._models) == 0
list_templates = [
t for t in param.concrete_descendents(BasicTemplate).values()
if not issubclass(t, ReactTemplate)
]
@latest_param
@pytest.mark.parametrize('template', list_templates)
def test_basic_template(template, document, comm):
tmplt = template(title='BasicTemplate', header_background='blue', header_color='red')
tmplt._update_vars()
tvars = tmplt._render_variables
assert tvars['app_title'] == 'BasicTemplate'
assert tvars['header_background'] == 'blue'
assert tvars['header_color'] == 'red'
assert tvars['nav'] == False
import param
import numpy as np
from bokeh.layouts import Column
from bokeh.models import Div as BkDiv, Slider as BkSlider
from panel.io import block_comm
from panel.models.widgets import Player as BkPlayer, FileInput as BkFileInput
from panel.widgets import (TextInput, StaticText, FloatSlider, IntSlider,
RangeSlider, LiteralInput, Checkbox, Select,
MultiSelect, Button, Toggle, DatePicker,
DateRangeSlider, DiscreteSlider, DatetimeInput,
CrossSelector, DiscretePlayer, ToggleGroup,
FileInput, Widget, CompositeWidget)
all_widgets = [
w for w in param.concrete_descendents(Widget).values()
if not w.__name__.startswith('_') and not issubclass(w, CompositeWidget)
]
@pytest.mark.parametrize('widget', all_widgets)
def test_widget_disabled_properties(widget, document, comm):
w = widget(disabled=True)
model = w._get_root(document, comm)
assert model.disabled == True
model.disabled = False
assert model.disabled == False
def __setitem__(self, key, val):
raise NotImplementedError("Models must define properties via the property_setup method")
def keys(self):
"The list of available property keys."
return self.properties.keys()
def items(self):
"The property items."
return self.properties.items()
# Register the sheets and projections available in Topographica
def register_submodel_decorators(classes,superclass=None):
"""
Register a Model decorator for each of the non-abstract classes provided.
Only registers those that are subclasses of the given superclass, if specified.
"""
with param.logging_level('CRITICAL'):
for c in classes:
if (isinstance(c, type) and
(superclass==None or issubclass(c, superclass)) and
(not hasattr(c, "_%s__abstract" % c.name))):
Model.register_decorator(c)
register_submodel_decorators(param.concrete_descendents(topo.sheet.Sheet).values())
register_submodel_decorators(param.concrete_descendents(topo.projection.Projection).values())