Source code for django_tables2.tables

# coding: utf-8
from __future__ import unicode_literals

import copy
from collections import OrderedDict

from django.core.paginator import Paginator
from django.db.models.fields import FieldDoesNotExist
from django.template.loader import get_template
from django.utils import six
from django.utils.functional import cached_property

from . import columns
from .config import RequestConfig
from .rows import BoundRows
from .utils import (Accessor, AttributeDict, OrderBy, OrderByTuple, Sequence,
                    computed_values, segment)

QUERYSET_ACCESSOR_SEPARATOR = '__'


[docs]class TableData(object): """ Exposes a consistent API for :term:`table data`. :param data: iterable containing data for each row :type data: `~django.db.query.QuerySet` or `list` of `dict` :param table: `.Table` object """ def __init__(self, data, table): self.table = table # data may be a QuerySet-like objects with count() and order_by() if (hasattr(data, 'count') and callable(data.count) and hasattr(data, 'order_by') and callable(data.order_by)): self.queryset = data # otherwise it must be convertable to a list else: # do some light validation if hasattr(data, '__iter__') or (hasattr(data, '__len__') and hasattr(data, '__getitem__')): self.list = list(data) else: raise ValueError( 'data must be QuerySet-like (have count and ' 'order_by) or support list(data) -- %s has ' 'neither' % type(data).__name__ ) def __len__(self): if not hasattr(self, "_length"): # Use the queryset count() method to get the length, instead of # loading all results into memory. This allows, for example, # smart paginators that use len() to perform better. self._length = ( self.queryset.count() if hasattr(self, 'queryset') else len(self.list) ) return self._length @property def data(self): return self.queryset if hasattr(self, "queryset") else self.list @property def ordering(self): """ Returns the list of order by aliases that are enforcing ordering on the data. If the data is unordered, an empty sequence is returned. If the ordering can not be determined, `None` is returned. This works by inspecting the actual underlying data. As such it's only supported for querysets. """ if hasattr(self, "queryset"): aliases = {} for bound_column in self.table.columns: aliases[bound_column.order_by_alias] = bound_column.order_by try: return next(segment(self.queryset.query.order_by, aliases)) except StopIteration: pass
[docs] def order_by(self, aliases): """ Order the data based on order by aliases (prefixed column names) in the table. :param aliases: optionally prefixed names of columns ('-' indicates descending order) in order of significance with regard to data ordering. :type aliases: `~.utils.OrderByTuple` """ accessors = [] for alias in aliases: bound_column = self.table.columns[OrderBy(alias).bare] # bound_column.order_by reflects the current ordering applied to # the table. As such we need to check the current ordering on the # column and use the opposite if it doesn't match the alias prefix. if alias[0] != bound_column.order_by_alias[0]: accessors += bound_column.order_by.opposite else: accessors += bound_column.order_by if hasattr(self, "queryset"): translate = lambda accessor: accessor.replace(Accessor.SEPARATOR, QUERYSET_ACCESSOR_SEPARATOR) if accessors: self.queryset = self.queryset.order_by(*(translate(a) for a in accessors)) else: self.list.sort(key=OrderByTuple(accessors).key)
[docs] def __iter__(self): """ for ... in ... default to using this. There's a bug in Django 1.3 with indexing into querysets, so this side-steps that problem (as well as just being a better way to iterate). """ return iter(self.data)
[docs] def __getitem__(self, key): """ Slicing returns a new `.TableData` instance, indexing returns a single record. """ return self.data[key]
@cached_property def verbose_name(self): """ The full (singular) name for the data. Queryset data has its model's `~django.db.Model.Meta.verbose_name` honored. List data is checked for a ``verbose_name`` attribute, and falls back to using ``"item"``. """ if hasattr(self, "queryset"): return self.queryset.model._meta.verbose_name return getattr(self.list, "verbose_name", "item") @cached_property def verbose_name_plural(self): """ The full (plural) name of the data. This uses the same approach as `TableData.verbose_name`. """ if hasattr(self, "queryset"): return self.queryset.model._meta.verbose_name_plural return getattr(self.list, "verbose_name_plural", "items")
class DeclarativeColumnsMetaclass(type): """ Metaclass that converts `.Column` objects defined on a class to the dictionary `.Table.base_columns`, taking into account parent class ``base_columns`` as well. """ def __new__(mcs, name, bases, attrs): attrs["_meta"] = opts = TableOptions(attrs.get("Meta", None)) # extract declared columns cols, remainder = [], {} for attr_name, attr in attrs.items(): if isinstance(attr, columns.Column): cols.append((attr_name, attr)) else: remainder[attr_name] = attr attrs = remainder cols.sort(key=lambda x: x[1].creation_counter) # If this class is subclassing other tables, add their fields as # well. Note that we loop over the bases in *reverse* - this is # necessary to preserve the correct order of columns. parent_columns = [] for base in bases[::-1]: if hasattr(base, "base_columns"): parent_columns = list(base.base_columns.items()) + parent_columns # Start with the parent columns attrs["base_columns"] = OrderedDict(parent_columns) # Possibly add some generated columns based on a model if opts.model: extra = OrderedDict() # honor Table.Meta.fields, fallback to model._meta.fields if opts.fields is not None: # Each item in opts.fields is the name of a model field or a # normal attribute on the model for field_name in opts.fields: try: field = opts.model._meta.get_field(field_name) except FieldDoesNotExist: extra[field_name] = columns.Column() else: extra[field_name] = columns.library.column_for_field(field) else: for field in opts.model._meta.fields: extra[field.name] = columns.library.column_for_field(field) attrs["base_columns"].update(extra) # Explicit columns override both parent and generated columns attrs["base_columns"].update(OrderedDict(cols)) # Apply any explicit exclude setting for exclusion in opts.exclude: if exclusion in attrs["base_columns"]: attrs["base_columns"].pop(exclusion) # Now reorder the columns based on explicit sequence if opts.sequence: opts.sequence.expand(attrs["base_columns"].keys()) # Table's sequence defaults to sequence declared in Meta # attrs['_sequence'] = opts.sequence attrs["base_columns"] = OrderedDict(((x, attrs["base_columns"][x]) for x in opts.sequence)) # set localize on columns for col_name in attrs["base_columns"].keys(): localize_column = None if col_name in opts.localize: localize_column = True # unlocalize gets higher precedence if col_name in opts.unlocalize: localize_column = False if localize_column is not None: attrs["base_columns"][col_name].localize = localize_column return super(DeclarativeColumnsMetaclass, mcs).__new__(mcs, name, bases, attrs) class TableOptions(object): """ Extracts and exposes options for a `.Table` from a `.Table.Meta` when the table is defined. See `.Table` for documentation on the impact of variables in this class. :param options: options for a table :type options: `.Table.Meta` on a `.Table` """ def __init__(self, options=None): super(TableOptions, self).__init__() self.attrs = AttributeDict(getattr(options, "attrs", {})) self.default = getattr(options, "default", "—") self.empty_text = getattr(options, "empty_text", None) self.fields = getattr(options, "fields", None) self.exclude = getattr(options, "exclude", ()) order_by = getattr(options, "order_by", None) if isinstance(order_by, six.string_types): order_by = (order_by, ) self.order_by = OrderByTuple(order_by) if order_by is not None else None self.order_by_field = getattr(options, "order_by_field", "sort") self.page_field = getattr(options, "page_field", "page") self.per_page = getattr(options, "per_page", 25) self.per_page_field = getattr(options, "per_page_field", "per_page") self.prefix = getattr(options, "prefix", "") self.show_header = getattr(options, "show_header", True) self.sequence = Sequence(getattr(options, "sequence", ())) self.orderable = getattr(options, "orderable", True) self.model = getattr(options, "model", None) self.template = getattr(options, "template", "django_tables2/table.html") self.localize = getattr(options, "localize", ()) self.unlocalize = getattr(options, "unlocalize", ()) class TableBase(object): """ A representation of a table. .. attribute:: attrs HTML attributes to add to the ``<table>`` tag. :type: `dict` When accessing the attribute, the value is always returned as an `.AttributeDict` to allow easily conversion to HTML. .. attribute:: columns The columns in the table. :type: `.BoundColumns` .. attribute:: default Text to render in empty cells (determined by `.Column.empty_values`, default `.Table.Meta.default`) :type: `unicode` .. attribute:: empty_text Empty text to render when the table has no data. (default `.Table.Meta.empty_text`) :type: `unicode` .. attribute:: exclude The names of columns that shouldn't be included in the table. :type: iterable of `unicode` .. attribute:: order_by_field If not `None`, defines the name of the *order by* querystring field. :type: `unicode` .. attribute:: page The current page in the context of pagination. Added during the call to `.Table.paginate`. .. attribute:: page_field If not `None`, defines the name of the *current page* querystring field. :type: `unicode` .. attribute:: paginator The current paginator for the table. Added during the call to `.Table.paginate`. .. attribute:: per_page_field If not `None`, defines the name of the *per page* querystring field. :type: `unicode` .. attribute:: show_header If `False`, the table will not have a header (`<thead>`), default value is `True` :type: `bool` .. attribute:: prefix A prefix for querystring fields to avoid name-clashes when using multiple tables on a single page. :type: `unicode` .. attribute:: rows The rows of the table (ignoring pagination). :type: `.BoundRows` .. attribute:: sequence The sequence/order of columns the columns (from left to right). :type: iterable Items in the sequence must be :term:`column names <column name>`, or ``"..."`` (string containing three periods). ``...`` can be used as a catch-all for columns that aren't specified. .. attribute:: orderable Enable/disable column ordering on this table :type: `bool` .. attribute:: template The template to render when using ``{% render_table %}`` (default ``"django_tables2/table.html"``) :type: `unicode` """ TableDataClass = TableData def __init__(self, data, order_by=None, orderable=None, empty_text=None, exclude=None, attrs=None, sequence=None, prefix=None, order_by_field=None, page_field=None, per_page_field=None, template=None, default=None, request=None, show_header=None): super(TableBase, self).__init__() self.exclude = exclude or () self.sequence = sequence self.data = self.TableDataClass(data=data, table=self) if default is None: default = self._meta.default self.default = default self.rows = BoundRows(data=self.data, table=self) attrs = computed_values(attrs if attrs is not None else self._meta.attrs) self.attrs = AttributeDict(attrs) self.empty_text = empty_text if empty_text is not None else self._meta.empty_text self.orderable = orderable self.prefix = prefix self.order_by_field = order_by_field self.page_field = page_field self.per_page_field = per_page_field self.show_header = show_header # Make a copy so that modifying this will not touch the class # definition. Note that this is different from forms, where the # copy is made available in a ``fields`` attribute. self.base_columns = copy.deepcopy(type(self).base_columns) # Keep fully expanded ``sequence`` at _sequence so it's easily accessible # during render. The priority is as follows: # 1. sequence passed in as an argument # 2. sequence declared in ``Meta`` # 3. sequence defaults to '...' if sequence is not None: self._sequence = Sequence(sequence) self._sequence.expand(self.base_columns.keys()) elif self._meta.sequence: self._sequence = self._meta.sequence else: if self._meta.fields is not None: self._sequence = Sequence(tuple(self._meta.fields) + ('...', )) else: self._sequence = Sequence(('...', )) self._sequence.expand(self.base_columns.keys()) self.columns = columns.BoundColumns(self) # `None` value for order_by means no order is specified. This means we # `shouldn't touch our data's ordering in any way. *However* # `table.order_by = None` means "remove any ordering from the data" # (it's equivalent to `table.order_by = ()`). if order_by is None and self._meta.order_by is not None: order_by = self._meta.order_by if order_by is None: self._order_by = None # If possible inspect the ordering on the data we were given and # update the table to reflect that. order_by = self.data.ordering if order_by is not None: self.order_by = order_by else: self.order_by = order_by self.template = template # If a request is passed, configure for request if request: RequestConfig(request).configure(self) def as_html(self, request): """ Render the table to a simple HTML table, adding `request` to the context. """ template = get_template(self.template) context = { 'table': self, 'request': request } return template.render(context) @property def attrs(self): return self._attrs @attrs.setter def attrs(self, value): self._attrs = value @property def show_header(self): return (self._show_header if self._show_header is not None else self._meta.show_header) @show_header.setter def show_header(self, value): self._show_header = value @property def empty_text(self): return self._empty_text @empty_text.setter def empty_text(self, value): self._empty_text = value @property def order_by(self): return self._order_by @order_by.setter def order_by(self, value): """ Order the rows of the table based on columns. :param value: iterable of order by aliases. """ # collapse empty values to () order_by = () if not value else value # accept string order_by = order_by.split(',') if isinstance(order_by, six.string_types) else order_by valid = [] # everything's been converted to a iterable, accept iterable! for alias in order_by: name = OrderBy(alias).bare if name in self.columns and self.columns[name].orderable: valid.append(alias) self._order_by = OrderByTuple(valid) self.data.order_by(self._order_by) @property def order_by_field(self): return (self._order_by_field if self._order_by_field is not None else self._meta.order_by_field) @order_by_field.setter def order_by_field(self, value): self._order_by_field = value @property def page_field(self): return (self._page_field if self._page_field is not None else self._meta.page_field) @page_field.setter def page_field(self, value): self._page_field = value def paginate(self, klass=Paginator, per_page=None, page=1, *args, **kwargs): """ Paginates the table using a paginator and creates a ``page`` property containing information for the current page. :type klass: Paginator class :param klass: a paginator class to paginate the results :type per_page: `int` :param per_page: how many records are displayed on each page :type page: `int` :param page: which page should be displayed. Extra arguments are passed to the paginator. Pagination exceptions (`~django.core.paginator.EmptyPage` and `~django.core.paginator.PageNotAnInteger`) may be raised from this method and should be handled by the caller. """ per_page = per_page or self._meta.per_page self.paginator = klass(self.rows, per_page, *args, **kwargs) self.page = self.paginator.page(page) @property def per_page_field(self): return (self._per_page_field if self._per_page_field is not None else self._meta.per_page_field) @per_page_field.setter def per_page_field(self, value): self._per_page_field = value @property def prefix(self): return (self._prefix if self._prefix is not None else self._meta.prefix) @prefix.setter def prefix(self, value): self._prefix = value @property def prefixed_order_by_field(self): return "%s%s" % (self.prefix, self.order_by_field) @property def prefixed_page_field(self): return "%s%s" % (self.prefix, self.page_field) @property def prefixed_per_page_field(self): return "%s%s" % (self.prefix, self.per_page_field) @property def sequence(self): return self._sequence @sequence.setter def sequence(self, value): if value: value = Sequence(value) value.expand(self.base_columns.keys()) self._sequence = value @property def orderable(self): if self._orderable is not None: return self._orderable else: return self._meta.orderable @orderable.setter def orderable(self, value): self._orderable = value @property def template(self): if self._template is not None: return self._template else: return self._meta.template @template.setter def template(self, value): self._template = value # Python 2/3 compatible way to enable the metaclass Table = DeclarativeColumnsMetaclass(str('Table'), (TableBase, ), {})