from six import BytesIO, StringIO, text_type, string_types from django.http import HttpResponse from django.contrib.contenttypes.models import ContentType try: from django.db.models.fields.related_descriptors import ManyToManyDescriptor except ImportError: # Django 1.8 compat hack. from django.db.models.fields.related import ( ReverseManyRelatedObjectsDescriptor as ManyToManyDescriptor ) from django.db.models import Avg, Count, Sum, Max, Min from openpyxl.workbook import Workbook from openpyxl.writer.excel import save_virtual_workbook from openpyxl.utils import get_column_letter from openpyxl.styles import Font import csv import re from collections import namedtuple from decimal import Decimal from numbers import Number from functools import reduce import datetime from .utils import ( get_relation_fields_from_model, get_properties_from_model, get_direct_fields_from_model, get_model_from_path_string, get_custom_fields_from_model, ) DisplayField = namedtuple( "DisplayField", "path path_verbose field field_verbose aggregate total group choices field_type", ) def generate_filename(title, ends_with): title = title.split('.')[0] title.replace(' ', '_') title += ('_' + datetime.datetime.now().strftime("%m%d_%H%M")) if not title.endswith(ends_with): title += ends_with return title class DataExportMixin(object): def build_sheet(self, data, ws, sheet_name='report', header=None, widths=None): first_row = 1 column_base = 1 ws.title = re.sub(r'\W+', '', sheet_name)[:30] if header: for i, header_cell in enumerate(header): cell = ws.cell(row=first_row, column=i + column_base) cell.value = header_cell cell.font = Font(bold=True) if widths: ws.column_dimensions[get_column_letter(i + 1)].width = widths[i] for row in data: for i in range(len(row)): item = row[i] # If item is a regular string if isinstance(item, str): # Change it to a unicode string try: row[i] = text_type(item) except UnicodeDecodeError: row[i] = text_type(item.decode('utf-8', 'ignore')) elif type(item) is dict: row[i] = text_type(item) # convert non native types to string elif type(item) not in {int, float, bool}: row[i] = text_type(item) try: ws.append(row) except ValueError as e: ws.append([e.message]) except: ws.append(['Unknown Error']) def build_xlsx_response(self, wb, title="report"): """ Take a workbook and return a xlsx file response """ title = generate_filename(title, '.xlsx') myfile = BytesIO() myfile.write(save_virtual_workbook(wb)) response = HttpResponse( myfile.getvalue(), content_type='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet') response['Content-Disposition'] = 'attachment; filename=%s' % title response['Content-Length'] = myfile.tell() return response def build_csv_response(self, wb, title="report"): """ Take a workbook and return a csv file response """ title = generate_filename(title, '.csv') myfile = StringIO() sh = wb.active c = csv.writer(myfile) for r in sh.rows: c.writerow([cell.value for cell in r]) response = HttpResponse( myfile.getvalue(), content_type='text/csv') response['Content-Disposition'] = 'attachment; filename=%s' % title response['Content-Length'] = myfile.tell() return response def list_to_workbook(self, data, title='report', header=None, widths=None): """ Create just a openpxl workbook from a list of data """ wb = Workbook() title = re.sub(r'\W+', '', title)[:30] if isinstance(data, dict): i = 0 for sheet_name, sheet_data in data.items(): if i > 0: wb.create_sheet() ws = wb.worksheets[i] self.build_sheet( sheet_data, ws, sheet_name=sheet_name, header=header) i += 1 else: ws = wb.worksheets[0] self.build_sheet(data, ws, header=header, widths=widths) return wb def list_to_xlsx_file(self, data, title='report', header=None, widths=None): """ Make 2D list into a xlsx response for download data can be a 2d array or a dict of 2d arrays like {'sheet_1': [['A1', 'B1']]} returns a StringIO file """ wb = self.list_to_workbook(data, title, header, widths) if not title.endswith('.xlsx'): title += '.xlsx' myfile = BytesIO() myfile.write(save_virtual_workbook(wb)) return myfile def list_to_csv_file(self, data, title='report', header=None, widths=None): """ Make a list into a csv response for download. """ wb = self.list_to_workbook(data, title, header, widths) if not title.endswith('.csv'): title += '.csv' myfile = StringIO() sh = wb.active c = csv.writer(myfile) for r in sh.rows: c.writerow([cell.value for cell in r]) return myfile def list_to_xlsx_response(self, data, title='report', header=None, widths=None): """ Make 2D list into a xlsx response for download data can be a 2d array or a dict of 2d arrays like {'sheet_1': [['A1', 'B1']]} """ wb = self.list_to_workbook(data, title, header, widths) return self.build_xlsx_response(wb, title=title) def list_to_csv_response(self, data, title='report', header=None, widths=None): """ Make 2D list into a csv response for download data. """ wb = self.list_to_workbook(data, title, header, widths) return self.build_csv_response(wb, title=title) def add_aggregates(self, queryset, display_fields): agg_funcs = { 'Avg': Avg, 'Min': Min, 'Max': Max, 'Count': Count, 'Sum': Sum } for display_field in display_fields: if display_field.aggregate: func = agg_funcs[display_field.aggregate] full_name = display_field.path + display_field.field queryset = queryset.annotate(func(full_name)) return queryset def report_to_list(self, queryset, display_fields, user=None, property_filters=[], preview=False): """ Create list from a report with all data filtering. queryset: initial queryset to generate results display_fields: list of field references or DisplayField models user: requesting user. If left as None - there will be no permission check property_filters: ??? preview: return only first 50 rows Returns list, message in case of issues. """ model_class = queryset.model def can_change_or_view(model): """ Return True iff `user` has either change or view permission for `model`. """ if user is None: return True model_name = model._meta.model_name app_label = model._meta.app_label can_change = user.has_perm(app_label + '.change_' + model_name) can_view = user.has_perm(app_label + '.view_' + model_name) return can_change or can_view if not can_change_or_view(model_class): return [], 'Permission Denied' if isinstance(display_fields, list): # Convert list of strings to DisplayField objects. new_display_fields = [] for display_field in display_fields: field_list = display_field.split('__') field = field_list[-1] path = '__'.join(field_list[:-1]) if path: path += '__' # Legacy format to append a __ here. new_model = get_model_from_path_string(model_class, path) model_field = new_model._meta.get_field_by_name(field)[0] choices = model_field.choices new_display_fields.append(DisplayField( path, '', field, '', '', None, None, choices, '' )) display_fields = new_display_fields # Build group-by field list. group = [df.path + df.field for df in display_fields if df.group] # To support group-by with multiple fields, we turn all the other # fields into aggregations. The default aggregation is `Max`. if group: for field in display_fields: if (not field.group) and (not field.aggregate): field.aggregate = 'Max' message = "" objects = self.add_aggregates(queryset, display_fields) # Display Values display_field_paths = [] property_list = {} custom_list = {} display_totals = {} for i, display_field in enumerate(display_fields): model = get_model_from_path_string(model_class, display_field.path) if display_field.field_type == "Invalid": continue if not model or can_change_or_view(model): display_field_key = display_field.path + display_field.field if display_field.field_type == "Property": property_list[i] = display_field_key elif display_field.field_type == "Custom Field": custom_list[i] = display_field_key elif display_field.aggregate == "Avg": display_field_key += '__avg' elif display_field.aggregate == "Max": display_field_key += '__max' elif display_field.aggregate == "Min": display_field_key += '__min' elif display_field.aggregate == "Count": display_field_key += '__count' elif display_field.aggregate == "Sum": display_field_key += '__sum' if display_field.field_type not in ('Property', 'Custom Field'): display_field_paths.append(display_field_key) if display_field.total: display_totals[display_field_key] = Decimal(0) else: message += 'Error: Permission denied on access to {0}.'.format( display_field.name ) def increment_total(display_field_key, val): """ Increment display total by `val` if given `display_field_key` in `display_totals`. """ if display_field_key in display_totals: if isinstance(val, bool): # True: 1, False: 0 display_totals[display_field_key] += Decimal(val) elif isinstance(val, Number): display_totals[display_field_key] += Decimal(str(val)) elif val: display_totals[display_field_key] += Decimal(1) # Select pk for primary and m2m relations in order to retrieve objects # for adding properties to report rows. Group-by queries do not support # Property nor Custom Field filters. if not group: display_field_paths.insert(0, 'pk') m2m_relations = [] for position, property_path in property_list.items(): property_root = property_path.split('__')[0] root_class = model_class try: property_root_class = getattr(root_class, property_root) except AttributeError: # django-hstore schema compatibility continue if type(property_root_class) == ManyToManyDescriptor: display_field_paths.insert(1, '%s__pk' % property_root) m2m_relations.append(property_root) if group: values = objects.values(*group) values = self.add_aggregates(values, display_fields) filtered_report_rows = [ [row[field] for field in display_field_paths] for row in values ] for row in filtered_report_rows: for pos, field in enumerate(display_field_paths): increment_total(field, row[pos]) else: filtered_report_rows = [] values_and_properties_list = [] values_list = objects.values_list(*display_field_paths) for row in values_list: row = list(row) values_and_properties_list.append(row[1:]) obj = None # we will get this only if needed for more complex processing # related_objects remove_row = False # filter properties (remove rows with excluded properties) for property_filter in property_filters: if not obj: obj = model_class.objects.get(pk=row.pop(0)) root_relation = property_filter.path.split('__')[0] if root_relation in m2m_relations: pk = row[0] if pk is not None: # a related object exists m2m_obj = getattr(obj, root_relation).get(pk=pk) val = reduce(getattr, [property_filter.field], m2m_obj) else: val = None else: if property_filter.field_type == 'Custom Field': for relation in property_filter.path.split('__'): if hasattr(obj, root_relation): obj = getattr(obj, root_relation) val = obj.get_custom_value(property_filter.field) else: val = reduce(getattr, (property_filter.path + property_filter.field).split('__'), obj) if property_filter.filter_property(val): remove_row = True values_and_properties_list.pop() break if not remove_row: for i, field in enumerate(display_field_paths[1:]): increment_total(field, row[i + 1]) for position, display_property in property_list.items(): if not obj: obj = model_class.objects.get(pk=row.pop(0)) relations = display_property.split('__') root_relation = relations[0] if root_relation in m2m_relations: pk = row.pop(0) if pk is not None: # a related object exists m2m_obj = getattr(obj, root_relation).get(pk=pk) val = reduce(getattr, relations[1:], m2m_obj) else: val = None else: # Could error if a related field doesn't exist try: val = reduce(getattr, relations, obj) except AttributeError: val = None values_and_properties_list[-1].insert(position, val) increment_total(display_property, val) for position, display_custom in custom_list.items(): if not obj: obj = model_class.objects.get(pk=row.pop(0)) val = obj.get_custom_value(display_custom) values_and_properties_list[-1].insert(position, val) increment_total(display_custom, val) filtered_report_rows.append(values_and_properties_list[-1]) if preview and len(filtered_report_rows) == 50: break # Sort results if requested. if hasattr(display_fields, 'filter'): defaults = { None: text_type, datetime.date: lambda: datetime.date(datetime.MINYEAR, 1, 1), datetime.datetime: lambda: datetime.datetime(datetime.MINYEAR, 1, 1), } # Order sort fields in reverse order so that ascending, descending # sort orders work together (based on Python's stable sort). See # http://stackoverflow.com/questions/6666748/ for details. sort_fields = display_fields.filter(sort__gt=0).order_by('-sort') sort_values = sort_fields.values_list('position', 'sort_reverse') for pos, reverse in sort_values: column = (row[pos] for row in filtered_report_rows) type_col = (type(val) for val in column if val is not None) field_type = next(type_col, None) default = defaults.get(field_type, field_type)() filtered_report_rows = sorted( filtered_report_rows, key=lambda row: self.sort_helper(row[pos], default), reverse=reverse, ) values_and_properties_list = filtered_report_rows # Build mapping from display field position to choices list. choice_lists = {} for df in display_fields: if df.choices and hasattr(df, 'choices_dict'): df_choices = df.choices_dict # Insert blank and None as valid choices. df_choices[''] = '' df_choices[None] = '' choice_lists[df.position] = df_choices # Build mapping from display field position to format. display_formats = {} for df in display_fields: if hasattr(df, 'display_format') and df.display_format: display_formats[df.position] = df.display_format def formatter(value, style): # Convert value to Decimal to apply numeric formats. try: value = Decimal(value) except Exception: pass try: return style.string.format(value) except ValueError: return value # Iterate rows and convert values by choice lists and field formats. final_list = [] for row in values_and_properties_list: row = list(row) for position, choice_list in choice_lists.items(): try: row[position] = text_type(choice_list[row[position]]) except Exception: row[position] = text_type(row[position]) for pos, style in display_formats.items(): row[pos] = formatter(row[pos], style) final_list.append(row) values_and_properties_list = final_list if display_totals: display_totals_row = [] fields_and_properties = list(display_field_paths[0 if group else 1:]) for position, value in property_list.items(): fields_and_properties.insert(position, value) for field in fields_and_properties: display_totals_row.append(display_totals.get(field, '')) # Add formatting to display totals. for pos, style in display_formats.items(): display_totals_row[pos] = formatter(display_totals_row[pos], style) values_and_properties_list.append( ['TOTALS'] + (len(fields_and_properties) - 1) * [''] ) values_and_properties_list.append(display_totals_row) return values_and_properties_list, message def sort_helper(self, value, default): if value is None: value = default if isinstance(value, string_types): value = value.lower() return value class GetFieldsMixin(object): def get_fields(self, model_class, field_name='', path='', path_verbose=''): """ Get fields and meta data from a model :param model_class: A django model class :param field_name: The field name to get sub fields from :param path: path of our field in format field_name__second_field_name__ect__ :param path_verbose: Human readable version of above :returns: Returns fields and meta data about such fields fields: Django model fields custom_fields: fields from django-custom-field if installed properties: Any properties the model has path: Our new path path_verbose: Our new human readable path :rtype: dict """ fields = get_direct_fields_from_model(model_class) properties = get_properties_from_model(model_class) custom_fields = get_custom_fields_from_model(model_class) app_label = model_class._meta.app_label model = model_class if field_name != '': field = model_class._meta.get_field(field_name) direct = field.concrete if path_verbose: path_verbose += "::" # TODO: need actual model name to generate choice list (not pluralized field name) # - maybe store this as a separate value? if field.many_to_many and hasattr(field, 'm2m_reverse_field_name'): path_verbose += field.m2m_reverse_field_name() else: path_verbose += field.name path += field_name path += '__' if direct: new_model = field.related_model path_verbose = new_model.__name__.lower() else: # Indirect related field new_model = field.related_model path_verbose = new_model.__name__.lower() fields = get_direct_fields_from_model(new_model) custom_fields = get_custom_fields_from_model(new_model) properties = get_properties_from_model(new_model) app_label = new_model._meta.app_label model = new_model return { 'fields': fields, 'custom_fields': custom_fields, 'properties': properties, 'path': path, 'path_verbose': path_verbose, 'app_label': app_label, 'model': model, } def get_related_fields(self, model_class, field_name, path="", path_verbose=""): """ Get fields for a given model """ if field_name: field = model_class._meta.get_field(field_name) direct = field.concrete if direct: try: related_field = field.remote_field except AttributeError: # Needed for Django < 1.9 related_field = field.related try: new_model = related_field.parent_model() except AttributeError: new_model = related_field.model else: # Indirect related field new_model = field.related_model if path_verbose: path_verbose += "::" path_verbose += field.name path += field_name path += '__' else: new_model = model_class new_fields = get_relation_fields_from_model(new_model) model_ct = ContentType.objects.get_for_model(new_model) return (new_fields, model_ct, path)