blob: fde7ebe9e124d07f71992b01347fbb81e419d1a5 [file] [log] [blame]
# Copyright 2016 The Chromium Authors. All rights reserved.
# Use of this source code is govered by a BSD-style
# license that can be found in the LICENSE file or at
# https://developers.google.com/open-source/licenses/bsd
"""Classes that help display pagination widgets for result sets."""
import logging
from third_party import ezt
import settings
from framework import framework_helpers
class VirtualPagination(object):
"""Class to calc Prev and Next pagination links based on result counts."""
def __init__(self, mr, total_count, items_per_page,
list_page_url=None, count_up=True,
start_param='start', num_param='num', max_num=None):
"""Given 'num' and 'start' params, determine Prev and Next links.
Args:
mr: commonly used info parsed from the request.
total_count: total number of artifacts that satisfy the query.
items_per_page: number of items to display on each page, e.g., 25.
list_page_url: URL of the web application page that is displaying
the list of artifacts. Used to build the Prev and Next URLs.
If None, no URLs will be built.
count_up: if False, count down from total_count.
start_param: query string parameter name to use for the start
of the pagination page.
num_param: query string parameter name to use for the number of items
to show on a pagination page.
max_num: optional limit on the value of the num param. If not given,
settings.max_artifact_search_results_per_page is used.
"""
self.total_count = total_count
self.prev_url = ''
self.reload_url = ''
self.next_url = ''
if max_num is None:
max_num = settings.max_artifact_search_results_per_page
self.num = mr.GetPositiveIntParam(num_param, items_per_page)
self.num = min(self.num, max_num)
if count_up:
self.start = mr.GetPositiveIntParam(start_param, 0)
self.last = min(self.total_count, self.start + self.num)
prev_start = max(0, self.start - self.num)
next_start = self.start + self.num
else:
self.start = mr.GetPositiveIntParam(start_param, self.total_count)
self.last = max(0, self.start - self.num)
prev_start = min(self.total_count, self.start + self.num)
next_start = self.start - self.num
if list_page_url:
if mr.project_name:
list_servlet_rel_url = '/p/%s%s' % (
mr.project_name, list_page_url)
else:
list_servlet_rel_url = list_page_url
self.reload_url = framework_helpers.FormatURL(
mr, list_servlet_rel_url,
**{start_param: self.start, num_param: self.num})
if prev_start != self.start:
self.prev_url = framework_helpers.FormatURL(
mr, list_servlet_rel_url,
**{start_param: prev_start, num_param: self.num})
if ((count_up and next_start < self.total_count) or
(not count_up and next_start >= 1)):
self.next_url = framework_helpers.FormatURL(
mr, list_servlet_rel_url,
**{start_param: next_start, num_param: self.num})
self.visible = ezt.boolean(self.last != self.start)
# Adjust indices to one-based values for display to users.
if count_up:
self.start += 1
else:
self.last += 1
def DebugString(self):
"""Return a string that is useful in on-page debugging."""
return '%s - %s of %s; prev_url:%s; next_url:%s' % (
self.start, self.last, self.total_count, self.prev_url, self.next_url)
class ArtifactPagination(VirtualPagination):
"""Class to calc Prev and Next pagination links based on a results list."""
def __init__(
self, mr, results, items_per_page, list_page_url, total_count=None,
limit_reached=False, skipped=0):
"""Given 'num' and 'start' params, determine Prev and Next links.
Args:
mr: commonly used info parsed from the request.
results: a list of artifact ids that satisfy the query.
items_per_page: number of items to display on each page, e.g., 25.
list_page_url: URL of the web application page that is displaying
the list of artifacts. Used to build the Prev and Next URLs.
total_count: specify total result count rather than the length of results
limit_reached: optional boolean that indicates that more results could
not be fetched because a limit was reached.
skipped: optional int number of items that were skipped and left off the
front of results.
"""
if total_count is None:
total_count = skipped + len(results)
super(ArtifactPagination, self).__init__(
mr, total_count, items_per_page, list_page_url=list_page_url)
self.limit_reached = ezt.boolean(limit_reached)
# Determine which of those results should be visible on the current page.
range_start = self.start - 1 - skipped
range_end = range_start + self.num
assert 0 <= range_start <= range_end
self.visible_results = results[range_start:range_end]