from collections import OrderedDict import sys from django.core.exceptions import SuspiciousOperation, ImproperlyConfigured from django.core.paginator import InvalidPage from django.core.urlresolvers import reverse from django.db import models from django.db.models.fields import FieldDoesNotExist from django.utils import six from django.utils.encoding import force_text from django.utils.translation import ugettext, ugettext_lazy from django.utils.http import urlencode from django.contrib.admin import FieldListFilter from django.contrib.admin.exceptions import DisallowedModelAdminLookup from django.contrib.admin.options import IncorrectLookupParameters, IS_POPUP_VAR, TO_FIELD_VAR from django.contrib.admin.utils import (quote, get_fields_from_path, lookup_needs_distinct, prepare_lookup_value) # Changelist settings ALL_VAR = 'all' ORDER_VAR = 'o' ORDER_TYPE_VAR = 'ot' PAGE_VAR = 'p' SEARCH_VAR = 'q' ERROR_FLAG = 'e' IGNORED_PARAMS = ( ALL_VAR, ORDER_VAR, ORDER_TYPE_VAR, SEARCH_VAR, IS_POPUP_VAR, TO_FIELD_VAR) # Text to display within change-list table cells if the value is blank. EMPTY_CHANGELIST_VALUE = ugettext_lazy('(None)') class ChangeList(object): def __init__(self, request, model, list_display, list_display_links, list_filter, date_hierarchy, search_fields, list_select_related, list_per_page, list_max_show_all, list_editable, model_admin): self.model = model self.opts = model._meta self.lookup_opts = self.opts self.root_queryset = model_admin.get_queryset(request) self.list_display = list_display self.list_display_links = list_display_links self.list_filter = list_filter self.date_hierarchy = date_hierarchy self.search_fields = search_fields self.list_select_related = list_select_related self.list_per_page = list_per_page self.list_max_show_all = list_max_show_all self.model_admin = model_admin self.preserved_filters = model_admin.get_preserved_filters(request) # Get search parameters from the query string. try: self.page_num = int(request.GET.get(PAGE_VAR, 0)) except ValueError: self.page_num = 0 self.show_all = ALL_VAR in request.GET self.is_popup = IS_POPUP_VAR in request.GET self.to_field = request.GET.get(TO_FIELD_VAR) self.params = dict(request.GET.items()) if PAGE_VAR in self.params: del self.params[PAGE_VAR] if ERROR_FLAG in self.params: del self.params[ERROR_FLAG] if self.is_popup: self.list_editable = () else: self.list_editable = list_editable self.query = request.GET.get(SEARCH_VAR, '') self.queryset = self.get_queryset(request) self.get_results(request) if self.is_popup: title = ugettext('Select %s') else: title = ugettext('Select %s to change') self.title = title % force_text(self.opts.verbose_name) self.pk_attname = self.lookup_opts.pk.attname def get_filters_params(self, params=None): """ Returns all params except IGNORED_PARAMS """ if not params: params = self.params lookup_params = params.copy() # a dictionary of the query string # Remove all the parameters that are globally and systematically # ignored. for ignored in IGNORED_PARAMS: if ignored in lookup_params: del lookup_params[ignored] return lookup_params def get_filters(self, request): lookup_params = self.get_filters_params() use_distinct = False for key, value in lookup_params.items(): if not self.model_admin.lookup_allowed(key, value): raise DisallowedModelAdminLookup("Filtering by %s not allowed" % key) filter_specs = [] if self.list_filter: for list_filter in self.list_filter: if callable(list_filter): # This is simply a custom list filter class. spec = list_filter(request, lookup_params, self.model, self.model_admin) else: field_path = None if isinstance(list_filter, (tuple, list)): # This is a custom FieldListFilter class for a given field. field, field_list_filter_class = list_filter else: # This is simply a field name, so use the default # FieldListFilter class that has been registered for # the type of the given field. field, field_list_filter_class = list_filter, FieldListFilter.create if not isinstance(field, models.Field): field_path = field field = get_fields_from_path(self.model, field_path)[-1] spec = field_list_filter_class(field, request, lookup_params, self.model, self.model_admin, field_path=field_path) # Check if we need to use distinct() use_distinct = (use_distinct or lookup_needs_distinct(self.lookup_opts, field_path)) if spec and spec.has_output(): filter_specs.append(spec) # At this point, all the parameters used by the various ListFilters # have been removed from lookup_params, which now only contains other # parameters passed via the query string. We now loop through the # remaining parameters both to ensure that all the parameters are valid # fields and to determine if at least one of them needs distinct(). If # the lookup parameters aren't real fields, then bail out. try: for key, value in lookup_params.items(): lookup_params[key] = prepare_lookup_value(key, value) use_distinct = (use_distinct or lookup_needs_distinct(self.lookup_opts, key)) return filter_specs, bool(filter_specs), lookup_params, use_distinct except FieldDoesNotExist as e: six.reraise(IncorrectLookupParameters, IncorrectLookupParameters(e), sys.exc_info()[2]) def get_query_string(self, new_params=None, remove=None): if new_params is None: new_params = {} if remove is None: remove = [] p = self.params.copy() for r in remove: for k in list(p): if k.startswith(r): del p[k] for k, v in new_params.items(): if v is None: if k in p: del p[k] else: p[k] = v return '?%s' % urlencode(sorted(p.items())) def get_results(self, request): paginator = self.model_admin.get_paginator(request, self.queryset, self.list_per_page) # Get the number of objects, with admin filters applied. result_count = paginator.count # Get the total number of objects, with no admin filters applied. # Perform a slight optimization: # full_result_count is equal to paginator.count if no filters # were applied if self.get_filters_params() or self.params.get(SEARCH_VAR): full_result_count = self.root_queryset.count() else: full_result_count = result_count can_show_all = result_count <= self.list_max_show_all multi_page = result_count > self.list_per_page # Get the list of objects to display on this page. if (self.show_all and can_show_all) or not multi_page: result_list = self.queryset._clone() else: try: result_list = paginator.page(self.page_num + 1).object_list except InvalidPage: raise IncorrectLookupParameters self.result_count = result_count self.full_result_count = full_result_count self.result_list = result_list self.can_show_all = can_show_all self.multi_page = multi_page self.paginator = paginator def _get_default_ordering(self): ordering = [] if self.model_admin.ordering: ordering = self.model_admin.ordering elif self.lookup_opts.ordering: ordering = self.lookup_opts.ordering return ordering def get_ordering_field(self, field_name): """ Returns the proper model field name corresponding to the given field_name to use for ordering. field_name may either be the name of a proper model field or the name of a method (on the admin or model) or a callable with the 'admin_order_field' attribute. Returns None if no proper model field name can be matched. """ try: field = self.lookup_opts.get_field(field_name) return field.name except models.FieldDoesNotExist: # See whether field_name is a name of a non-field # that allows sorting. if callable(field_name): attr = field_name elif hasattr(self.model_admin, field_name): attr = getattr(self.model_admin, field_name) else: attr = getattr(self.model, field_name) return getattr(attr, 'admin_order_field', None) def get_ordering(self, request, queryset): """ Returns the list of ordering fields for the change list. First we check the get_ordering() method in model admin, then we check the object's default ordering. Then, any manually-specified ordering from the query string overrides anything. Finally, a deterministic order is guaranteed by ensuring the primary key is used as the last ordering field. """ params = self.params ordering = list(self.model_admin.get_ordering(request) or self._get_default_ordering()) if ORDER_VAR in params: # Clear ordering and used params ordering = [] order_params = params[ORDER_VAR].split('.') for p in order_params: try: none, pfx, idx = p.rpartition('-') field_name = self.list_display[int(idx)] order_field = self.get_ordering_field(field_name) if not order_field: continue # No 'admin_order_field', skip it # reverse order if order_field has already "-" as prefix if order_field.startswith('-') and pfx == "-": ordering.append(order_field[1:]) else: ordering.append(pfx + order_field) except (IndexError, ValueError): continue # Invalid ordering specified, skip it. # Add the given query's ordering fields, if any. ordering.extend(queryset.query.order_by) # Ensure that the primary key is systematically present in the list of # ordering fields so we can guarantee a deterministic order across all # database backends. pk_name = self.lookup_opts.pk.name if not (set(ordering) & set(['pk', '-pk', pk_name, '-' + pk_name])): # The two sets do not intersect, meaning the pk isn't present. So # we add it. ordering.append('-pk') return ordering def get_ordering_field_columns(self): """ Returns an OrderedDict of ordering field column numbers and asc/desc """ # We must cope with more than one column having the same underlying sort # field, so we base things on column numbers. ordering = self._get_default_ordering() ordering_fields = OrderedDict() if ORDER_VAR not in self.params: # for ordering specified on ModelAdmin or model Meta, we don't know # the right column numbers absolutely, because there might be more # than one column associated with that ordering, so we guess. for field in ordering: if field.startswith('-'): field = field[1:] order_type = 'desc' else: order_type = 'asc' for index, attr in enumerate(self.list_display): if self.get_ordering_field(attr) == field: ordering_fields[index] = order_type break else: for p in self.params[ORDER_VAR].split('.'): none, pfx, idx = p.rpartition('-') try: idx = int(idx) except ValueError: continue # skip it ordering_fields[idx] = 'desc' if pfx == '-' else 'asc' return ordering_fields def get_queryset(self, request): # First, we collect all the declared list filters. (self.filter_specs, self.has_filters, remaining_lookup_params, filters_use_distinct) = self.get_filters(request) # Then, we let every list filter modify the queryset to its liking. qs = self.root_queryset for filter_spec in self.filter_specs: new_qs = filter_spec.queryset(request, qs) if new_qs is not None: qs = new_qs try: # Finally, we apply the remaining lookup parameters from the query # string (i.e. those that haven't already been processed by the # filters). qs = qs.filter(**remaining_lookup_params) except (SuspiciousOperation, ImproperlyConfigured): # Allow certain types of errors to be re-raised as-is so that the # caller can treat them in a special way. raise except Exception as e: # Every other error is caught with a naked except, because we don't # have any other way of validating lookup parameters. They might be # invalid if the keyword arguments are incorrect, or if the values # are not in the correct type, so we might get FieldError, # ValueError, ValidationError, or ?. raise IncorrectLookupParameters(e) if not qs.query.select_related: qs = self.apply_select_related(qs) # Set ordering. ordering = self.get_ordering(request, qs) qs = qs.order_by(*ordering) # Apply search results qs, search_use_distinct = self.model_admin.get_search_results( request, qs, self.query) # Remove duplicates from results, if necessary if filters_use_distinct | search_use_distinct: return qs.distinct() else: return qs def apply_select_related(self, qs): if self.list_select_related is True: return qs.select_related() if self.list_select_related is False: if self.has_related_field_in_list_display(): return qs.select_related() if self.list_select_related: return qs.select_related(*self.list_select_related) return qs def has_related_field_in_list_display(self): for field_name in self.list_display: try: field = self.lookup_opts.get_field(field_name) except models.FieldDoesNotExist: pass else: if isinstance(field.rel, models.ManyToOneRel): return True return False def url_for_result(self, result): pk = getattr(result, self.pk_attname) return reverse('admin:%s_%s_change' % (self.opts.app_label, self.opts.model_name), args=(quote(pk),), current_app=self.model_admin.admin_site.name)