IfcOpenShell/src/ifcopenshell-python/ifcopenshell/file.py

###############################################################################
#                                                                             #
# This file is part of IfcOpenShell.                                          #
#                                                                             #
# IfcOpenShell is free software: you can redistribute it and/or modify        #
# it under the terms of the Lesser GNU General Public License as published by #
# the Free Software Foundation, either version 3.0 of the License, or         #
# (at your option) any later version.                                         #
#                                                                             #
# IfcOpenShell is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                #
# Lesser GNU General Public License for more details.                         #
#                                                                             #
# You should have received a copy of the Lesser GNU General Public License    #
# along with this program. If not, see <http://www.gnu.org/licenses/>.        #
#                                                                             #
###############################################################################

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import numbers
import functools

from . import ifcopenshell_wrapper
from .entity_instance import entity_instance

try:
    # Python 2
    basestring
except NameError:
    # Python 3 or newer
    basestring = (str, bytes)


class file(object):
    """Base class for containing IFC files.

    Class has instance methods for filtering by element Id, Type, etc.
    Instantiated objects can be subscripted by Id or Guid

    Example::

        ifc_file = ifcopenshell.open(file_path)
        products = ifc_file.by_type("IfcProduct")
        print(products[0].id(), products[0].GlobalId)
        >>> 122 2XQ$n5SLP5MBLyL442paFx
        # Subscripting
        print(products[0] == ifc_file[122] == ifc_file['2XQ$n5SLP5MBLyL442paFx'])
        >>> True
    """
    def __init__(self, f=None, schema=None):
        if f is not None:
            self.wrapped_data = f
        else:
            args = filter(None, [schema])
            args = map(ifcopenshell_wrapper.schema_by_name, args)
            self.wrapped_data = ifcopenshell_wrapper.file(*args)

    def create_entity(self, type, *args, **kwargs):
        """Create a new IFC entity in the file.

        :param type: Case insensitive name of the IFC class
        :type type: string
        :param args: The positional arguments of the IFC class
        :param kwargs: The keyword arguments of the IFC class
        :returns: An entity instance
        :rtype: ifcopenshell.entity_instance.entity_instance

        Example::

            f = ifcopenshell.file()
            f.create_entity('IfcPerson')
            >>> #1=IfcPerson($,$,$,$,$,$,$,$)
            f.create_entity('IfcPerson', 'Foobar')
            >>> #2=IfcPerson('Foobar',$,$,$,$,$,$,$)
            f.create_entity('IfcPerson', Identification='Foobar')
            >>> #3=IfcPerson('Foobar',$,$,$,$,$,$,$)
        """
        e = entity_instance((self.schema, type))
        self.wrapped_data.add(e.wrapped_data)
        e.wrapped_data.this.disown()
        attrs = list(enumerate(args)) + \
            [(e.wrapped_data.get_argument_index(name), arg) for name, arg in kwargs.items()]
        for idx, arg in attrs:
            e[idx] = arg
        return e

    def __getattr__(self, attr):
        if attr[0:6] == 'create':
            return functools.partial(self.create_entity, attr[6:])
        else:
            return getattr(self.wrapped_data, attr)

    def __getitem__(self, key):
        if isinstance(key, numbers.Integral):
            return entity_instance(self.wrapped_data.by_id(key))
        elif isinstance(key, basestring):
            return entity_instance(self.wrapped_data.by_guid(str(key)))

    def by_id(self, id):
        """Return IFC objects filtered by IFC ID.

        :param id: STEP numerical identifier
        :type id: int
        :returns: Returned objects are unwrapped IFC objects.
        :rtype: ifcopenshell.entity_instance.entity_instance
        """
        return self[id]

    def by_guid(self, guid):
        """Return IFC objects filtered by IFC GUID.

        :param guid: GlobalId value in 22-character encoded form
        :type guid: string
        :returns: Returned objects are unwrapped IFC objects.
        :rtype: ifcopenshell.entity_instance.entity_instance
        """
        return self[guid]

    def add(self, inst):
        """Undocumented function"""
        inst.wrapped_data.this.disown()
        return entity_instance(self.wrapped_data.add(inst.wrapped_data))

    def by_type(self, type):
        """Return IFC objects filtered by IFC Type and wrapped with the entity_instance class.

        If an IFC type class has subclasses, all entities of those subclasses are also returned.

        :param type: The case insensitive type of IFC class to return.
        :type type: string
        :returns: A list of ifcopenshell.entity_instance.entity_instance objects
        :rtype: list
        """
        return [entity_instance(e) for e in self.wrapped_data.by_type(type)]

    def traverse(self, inst, max_levels=None):
        """Get a list of all referenced entities for a particular entity

        :param inst: The entity instance to get all sub instances
        :type inst: ifcopenshell.entity_instance.entity_instance
        :param max_levels: How far deep to recursively fetch sub instances. None or -1 means infinite.
        :type max_levels: None|int
        :returns: A list of ifcopenshell.entity_instance.entity_instance objects
        :rtype: list
        """
        if max_levels is None:
            max_levels = -1
        return [entity_instance(e) for e in self.wrapped_data.traverse(inst.wrapped_data, max_levels)]

    def get_inverse(self, inst):
        """Return a list of entities that reference this entity

        :param inst: The entity instance to get inverse relationships
        :type inst: ifcopenshell.entity_instance.entity_instance
        :returns: A list of ifcopenshell.entity_instance.entity_instance objects
        :rtype: list
        """
        return [entity_instance(e) for e in self.wrapped_data.get_inverse(inst.wrapped_data)]

    def remove(self, inst):
        """Deletes an IFC object in the file.

        Other entities that reference the deleted object will be set to null.

        :param inst: The entity instance to delete
        :type inst: ifcopenshell.entity_instance.entity_instance
        :rtype: None
        """
        return self.wrapped_data.remove(inst.wrapped_data)

    def __iter__(self):
        return iter(self[id] for id in self.wrapped_data.entity_names())

    @staticmethod
    def from_string(s):
        return file(ifcopenshell_wrapper.read(s))