--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/views/helper/lists.py Fri Oct 03 22:09:32 2008 +0000
@@ -0,0 +1,213 @@
+#!/usr/bin/python2.5
+#
+# Copyright 2008 the Melange authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Helpers used to render lists.
+"""
+
+__authors__ = [
+ '"Chen Lunpeng" <forever.clp@gmail.com>',
+ '"Pawel Solyga" <pawel.solyga@gmail.com>',
+ ]
+
+
+from soc.views.helpers import forms_helpers
+
+
+DEF_PAGINATION = 10
+MAX_PAGINATION = 100
+
+DEF_PAGINATION_CHOICES = (
+ ('10', '10 items per page'),
+ ('25', '25 items per page'),
+ ('50', '50 items per page'),
+ ('100', '100 items per page'),
+)
+
+
+def getPreferredListPagination(user=None):
+ """Returns User's preferred list pagination limit.
+
+ Args:
+ user: User entity containing the list pagination preference;
+ default is None, to use the current logged-in User
+ """
+ # TODO: eventually this limit should be a User profile preference
+ # (stored in the site-wide User Model) preference
+ return DEF_PAGINATION
+
+
+def cleanListParameters(offset=None, limit=None):
+ """Converts and validates offset and limit values of the list.
+
+ Args:
+ offset: offset in list which defines first item to return
+ limit: max amount of items per page
+
+ Returns:
+ updated offset and limit values
+ """
+ # update offset value
+ try:
+ offset = int(offset)
+ except:
+ # also catches offset=None case where offset not supplied
+ offset = 0
+
+ # update limit value
+ try:
+ limit = int(limit)
+ except:
+ # also catches limit=None case where limit not supplied
+ limit = getPreferredListPagination()
+
+ return max(0, offset), max(1, min(limit, MAX_PAGINATION))
+
+
+DEF_LIST_TEMPLATES = {'list_main': 'soc/list/list_main.html',
+ 'list_pagination': 'soc/list/list_pagination.html',
+ 'list_row': 'soc/list/list_row.html',
+ 'list_heading': 'soc/list/list_heading.html'}
+
+def setList(request, context, list_data,
+ offset=0, limit=0, list_templates=DEF_LIST_TEMPLATES):
+ """Updates template context dict with variables used for rendering lists.
+
+ Args:
+ request: the Django HTTP request object
+ context: the template context dict to be updated in-place (pass in a copy
+ if the original must not be modified), or None if a new one is to be
+ created; any existing fields already present in the context dict passed
+ in by the caller are left unaltered
+ list_data: array of data to be displayed in the list
+ offset: offset in list which defines first item to return
+ limit: max amount of items per page
+ list_templates: templates that are used when rendering list
+
+ Returns:
+ updated template context dict supplied by the caller or a new context
+ dict if the caller supplied None
+
+ {
+ 'list_data': list data to be displayed
+ 'list_main': url to list main template
+ 'list_pagination': url to list pagination template
+ 'list_row': url to list row template
+ 'list_heading': url to list heading template
+ 'limit': max amount of items per page,
+ 'newest': url to first page of the list
+ 'prev': url to previous page
+ 'next': url to next page
+ 'first': offset of the first item in the list
+ 'last': offest of the lst item in the list
+ }
+ """
+ if not list_data:
+ list_data = []
+
+ more = bool(list_data[limit:])
+ if more:
+ del list_data[limit:]
+ if more:
+ next = request.path + '?offset=%d&limit=%d' % (offset+limit, limit)
+ else:
+ next = ''
+ if offset > 0:
+ prev = request.path + '?offset=%d&limit=%d' % (max(0, offset-limit), limit)
+ else:
+ prev = ''
+ newest = ''
+ if offset > limit:
+ newest = request.path + '?limit=%d' % limit
+
+ if not context:
+ context = {}
+
+ context.update(
+ {'list_data': list_data,
+ 'list_main': list_templates['list_main'],
+ 'list_pagination': list_templates['list_pagination'],
+ 'list_row': list_templates['list_row'],
+ 'list_heading': list_templates['list_heading'],
+ 'limit': limit,
+ 'newest': newest,
+ 'prev': prev,
+ 'next': next,
+ 'first': offset+1,
+ 'last': len(list_data) > 1 and offset+len(list_data) or None})
+
+ return context
+
+
+def makePaginationForm(
+ request, limit, arg_name='limit', choices=DEF_PAGINATION_CHOICES,
+ field_name_fmt=forms_helpers.DEF_SELECT_QUERY_ARG_FIELD_NAME_FMT):
+ """Returns a customized pagination limit selection form.
+
+ Args:
+ request: the standard Django HTTP request object
+ limit: the initial value of the selection control
+ arg_name: see forms_helpers.makeSelectQueryArgForm(); default is 'limit'
+ choices: see forms_helpers.makeSelectQueryArgForm(); default is
+ DEF_PAGINATION_CHOICES
+ field_name_fmt: see forms_helpers.makeSelectQueryArgForm()
+ """
+ choices = makeNewPaginationChoices(limit=limit, choices=choices)
+
+ return forms_helpers.makeSelectQueryArgForm(
+ request, arg_name, limit, choices)
+
+
+def makeNewPaginationChoices(limit=DEF_PAGINATION,
+ choices=DEF_PAGINATION_CHOICES):
+ """Updates the pagination limit selection form.
+
+ Args:
+ limit: the initial value of the selection control;
+ default is DEF_PAGINATION
+ choices: see forms_helpers.makeSelectQueryArgForm();
+ default is DEF_PAGINATION_CHOICES
+
+ Returns:
+ a new pagination choices list if limit is not in
+ DEF_PAGINATION_CHOICES, or DEF_PAGINATION_CHOICES otherwise
+ """
+ # determine where to insert the new limit into choices
+ new_choices = []
+ inserted = False
+
+ for pagination, label in choices:
+ items = int(pagination)
+
+ if limit == items:
+ # limit is already present, so just return existing choices
+ return choices
+
+ if (not inserted) and (limit < items):
+ # limit needs to be inserted before the current pagination,
+ # so assemble a new choice tuple and append it
+ choice = (str(limit), '%s items per page' % limit)
+ new_choices.append(choice)
+ inserted = True
+
+ # append the existing choice
+ new_choices.append((pagination, label))
+
+ if not inserted:
+ # new choice must go last, past all other existing choices
+ choice = (str(limit), '%s items per page' % limit)
+ new_choices.append(choice)
+
+ return new_choices