# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb 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 GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""This module provides some generic components to navigate in the web
application.
Pagination
----------
Several implementations for large result set pagination are provided:
.. autoclass:: PageNavigation
.. autoclass:: PageNavigationSelect
.. autoclass:: SortedNavigation
Pagination will appear when needed according to the `page-size` ui property.
This module monkey-patch the :func:`paginate` function to the base :class:`View`
class, so that you can ask pagination explicitly on every result-set based views.
.. autofunction:: paginate
Previous / next navigation
--------------------------
An adapter and its related component for the somewhat usal "previous / next"
navigation are provided.
.. autoclass:: IPrevNextAdapter
.. autoclass:: NextPrevNavigationComponent
"""
__docformat__ = "restructuredtext en"
from cubicweb import _
from datetime import datetime
from six import text_type
from rql.nodes import VariableRef, Constant
from logilab.mtconverter import xml_escape
from logilab.common.deprecation import deprecated
from cubicweb.predicates import paginated_rset, sorted_rset, adaptable
from cubicweb.uilib import cut
from cubicweb.view import EntityAdapter
from cubicweb.web.component import EmptyComponent, EntityCtxComponent, NavigationComponent
class PageNavigation(NavigationComponent):
"""The default pagination component: display link to pages where each pages
is identified by the item number of its first and last elements.
"""
def call(self):
"""displays a resultset by page"""
params = dict(self._cw.form)
self.clean_params(params)
basepath = self._cw.relative_path(includeparams=False)
self.w(u'<div class="pagination">')
self.w(self.previous_link(basepath, params))
self.w(u'[ %s ]' %
u' | '.join(self.iter_page_links(basepath, params)))
self.w(u'  %s' % self.next_link(basepath, params))
self.w(u'</div>')
def index_display(self, start, stop):
return u'%s - %s' % (start+1, stop+1)
def iter_page_links(self, basepath, params):
rset = self.cw_rset
page_size = self.page_size
start = 0
while start < rset.rowcount:
stop = min(start + page_size - 1, rset.rowcount - 1)
yield self.page_link(basepath, params, start, stop,
self.index_display(start, stop))
start = stop + 1
class PageNavigationSelect(PageNavigation):
"""This pagination component displays a result-set by page as
:class:`PageNavigation` but in a <select>, which is better when there are a
lot of results.
By default it will be selected when there are more than 4 pages to be
displayed.
"""
__select__ = paginated_rset(4)
page_link_templ = u'<option value="%s" title="%s">%s</option>'
selected_page_link_templ = u'<option value="%s" selected="selected" title="%s">%s</option>'
def call(self):
params = dict(self._cw.form)
self.clean_params(params)
basepath = self._cw.relative_path(includeparams=False)
w = self.w
w(u'<div class="pagination">')
w(self.previous_link(basepath, params))
w(u'<select onchange="javascript: document.location=this.options[this.selectedIndex].value">')
for option in self.iter_page_links(basepath, params):
w(option)
w(u'</select>')
w(u'  %s' % self.next_link(basepath, params))
w(u'</div>')
class SortedNavigation(NavigationComponent):
"""This pagination component will be selected by default if there are less
than 4 pages and if the result set is sorted.
Displayed links to navigate accross pages of a result set are done according
to the first variable on which the sort is done, and looks like:
[ana - cro] | [cro - ghe] | ... | [tim - zou]
You may want to override this component to customize display in some cases.
.. automethod:: sort_on
.. automethod:: display_func
.. automethod:: format_link_content
.. automethod:: write_links
Below an example from the tracker cube:
.. sourcecode:: python
class TicketsNavigation(navigation.SortedNavigation):
__select__ = (navigation.SortedNavigation.__select__
& ~paginated_rset(4) & is_instance('Ticket'))
def sort_on(self):
col, attrname = super(TicketsNavigation, self).sort_on()
if col == 6:
# sort on state, we don't want that
return None, None
return col, attrname
The idea is that in trackers'ticket tables, result set is first ordered on
ticket's state while this doesn't make any sense in the navigation. So we
override :meth:`sort_on` so that if we detect such sorting, we disable the
feature to go back to item number in the pagination.
Also notice the `~paginated_rset(4)` in the selector so that if there are
more than 4 pages to display, :class:`PageNavigationSelect` will still be
selected.
"""
__select__ = paginated_rset() & sorted_rset()
# number of considered chars to build page links
nb_chars = 5
def call(self):
# attrname = the name of attribute according to which the sort
# is done if any
col, attrname = self.sort_on()
index_display = self.display_func(self.cw_rset, col, attrname)
basepath = self._cw.relative_path(includeparams=False)
params = dict(self._cw.form)
self.clean_params(params)
blocklist = []
start = 0
total = self.cw_rset.rowcount
while start < total:
stop = min(start + self.page_size - 1, total - 1)
cell = self.format_link_content(index_display(start), index_display(stop))
blocklist.append(self.page_link(basepath, params, start, stop, cell))
start = stop + 1
self.write_links(basepath, params, blocklist)
def display_func(self, rset, col, attrname):
"""Return a function that will be called with a row number as argument
and should return a string to use as link for it.
"""
if attrname is not None:
def index_display(row):
if not rset[row][col]: # outer join
return u''
entity = rset.get_entity(row, col)
return entity.printable_value(attrname, format='text/plain')
elif col is None: # smart links disabled.
def index_display(row):
return text_type(row)
elif self._cw.vreg.schema.eschema(rset.description[0][col]).final:
def index_display(row):
return text_type(rset[row][col])
else:
def index_display(row):
return rset.get_entity(row, col).view('text')
return index_display
def sort_on(self):
"""Return entity column number / attr name to use for nice display by
inspecting the rset'syntax tree.
"""
rschema = self._cw.vreg.schema.rschema
for sorterm in self.cw_rset.syntax_tree().children[0].orderby:
if isinstance(sorterm.term, Constant):
col = sorterm.term.value - 1
return col, None
var = sorterm.term.get_nodes(VariableRef)[0].variable
col = None
for ref in var.references():
rel = ref.relation()
if rel is None:
continue
attrname = rel.r_type
if attrname in ('is', 'has_text'):
continue
if not rschema(attrname).final:
col = var.selected_index()
attrname = None
if col is None:
# final relation or not selected non final relation
if var is rel.children[0]:
relvar = rel.children[1].children[0].get_nodes(VariableRef)[0]
else:
relvar = rel.children[0].variable
col = relvar.selected_index()
if col is not None:
break
else:
# no relation but maybe usable anyway if selected
col = var.selected_index()
attrname = None
if col is not None:
# if column type is date[time], set proper 'nb_chars'
if var.stinfo['possibletypes'] & frozenset(('TZDatetime', 'Datetime',
'Date')):
self.nb_chars = len(self._cw.format_date(datetime.today()))
return col, attrname
# nothing usable found, use the first column
return 0, None
def format_link_content(self, startstr, stopstr):
"""Return text for a page link, where `startstr` and `stopstr` are the
text for the lower/upper boundaries of the page.
By default text are stripped down to :attr:`nb_chars` characters.
"""
text = u'%s - %s' % (startstr.lower()[:self.nb_chars],
stopstr.lower()[:self.nb_chars])
return xml_escape(text)
def write_links(self, basepath, params, blocklist):
"""Return HTML for the whole navigation: `blocklist` is a list of HTML
snippets for each page, `basepath` and `params` will be necessary to
build previous/next links.
"""
self.w(u'<div class="pagination">')
self.w(u'%s ' % self.previous_link(basepath, params))
self.w(u'[ %s ]' % u' | '.join(blocklist))
self.w(u' %s' % self.next_link(basepath, params))
self.w(u'</div>')
def do_paginate(view, rset=None, w=None, show_all_option=True, page_size=None):
"""write pages index in w stream (default to view.w) and then limit the
result set (default to view.rset) to the currently displayed page if we're
not explicitly told to display everything (by setting __force_display in
req.form)
"""
req = view._cw
if rset is None:
rset = view.cw_rset
if w is None:
w = view.w
nav = req.vreg['components'].select_or_none(
'navigation', req, rset=rset, page_size=page_size, view=view)
if nav:
if w is None:
w = view.w
if req.form.get('__force_display'):
# allow to come back to the paginated view
params = dict(req.form)
basepath = req.relative_path(includeparams=False)
del params['__force_display']
url = nav.page_url(basepath, params)
w(u'<div class="displayAllLink"><a href="%s">%s</a></div>\n'
% (xml_escape(url), req._('back to pagination (%s results)')
% nav.page_size))
else:
# get boundaries before component rendering
start, stop = nav.page_boundaries()
nav.render(w=w)
params = dict(req.form)
nav.clean_params(params)
# make a link to see them all
if show_all_option:
basepath = req.relative_path(includeparams=False)
params['__force_display'] = 1
params['__fromnavigation'] = 1
url = nav.page_url(basepath, params)
w(u'<div class="displayAllLink"><a href="%s">%s</a></div>\n'
% (xml_escape(url), req._('show %s results') % len(rset)))
rset.limit(offset=start, limit=stop-start, inplace=True)
def paginate(view, show_all_option=True, w=None, page_size=None, rset=None):
"""paginate results if the view is paginable
"""
if view.paginable:
do_paginate(view, rset, w, show_all_option, page_size)
# monkey patch base View class to add a .paginate([...])
# method to be called to write pages index in the view and then limit the result
# set to the current page
from cubicweb.view import View
View.do_paginate = do_paginate
View.paginate = paginate
View.handle_pagination = False
class IPrevNextAdapter(EntityAdapter):
"""Interface for entities which can be linked to a previous and/or next
entity
.. automethod:: next_entity
.. automethod:: previous_entity
"""
__needs_bw_compat__ = True
__regid__ = 'IPrevNext'
__abstract__ = True
def next_entity(self):
"""return the 'next' entity"""
raise NotImplementedError
def previous_entity(self):
"""return the 'previous' entity"""
raise NotImplementedError
class NextPrevNavigationComponent(EntityCtxComponent):
"""Entities adaptable to the 'IPrevNext' should have this component
automatically displayed. You may want to override this component to have a
different look and feel.
"""
__regid__ = 'prevnext'
# register msg not generated since no entity implements IPrevNext in cubicweb
# itself
help = _('ctxcomponents_prevnext_description')
__select__ = EntityCtxComponent.__select__ & adaptable('IPrevNext')
context = 'navbottom'
order = 10
@property
def prev_icon(self):
return '<img src="%s" alt="%s" />' % (
xml_escape(self._cw.data_url('go_prev.png')), self._cw._('previous page'))
@property
def next_icon(self):
return '<img src="%s" alt="%s" />' % (
xml_escape(self._cw.data_url('go_next.png')), self._cw._('next page'))
def init_rendering(self):
adapter = self.entity.cw_adapt_to('IPrevNext')
self.previous = adapter.previous_entity()
self.next = adapter.next_entity()
if not (self.previous or self.next):
raise EmptyComponent()
def render_body(self, w):
w(u'<div class="prevnext">')
self.prevnext(w)
w(u'</div>')
w(u'<div class="clear"></div>')
def prevnext(self, w):
if self.previous:
self.prevnext_entity(w, self.previous, 'prev')
if self.next:
self.prevnext_entity(w, self.next, 'next')
def prevnext_entity(self, w, entity, type):
textsize = self._cw.property_value('navigation.short-line-size')
content = xml_escape(cut(entity.dc_title(), textsize))
if type == 'prev':
title = self._cw._('i18nprevnext_previous')
icon = self.prev_icon
cssclass = u'previousEntity left'
content = icon + '  ' + content
else:
title = self._cw._('i18nprevnext_next')
icon = self.next_icon
cssclass = u'nextEntity right'
content = content + '  ' + icon
self.prevnext_div(w, type, cssclass, entity.absolute_url(),
title, content)
def prevnext_div(self, w, type, cssclass, url, title, content):
w(u'<div class="%s">' % cssclass)
w(u'<a href="%s" title="%s">%s</a>' % (xml_escape(url),
xml_escape(title),
content))
w(u'</div>')
self._cw.html_headers.add_raw('<link rel="%s" href="%s" />' % (
type, xml_escape(url)))