collective.nextprev 0.2

The collective.nextprev package extends Plone’s next/previous navigation for folders to collections (AKA topics or smart folders). If a listing view is visited for a collection which has next/previous navigation enabled, a cookie is set to remember the collection used and any relevant query terms. When a content item in the result set is visited, this cookie will be used to determine the next and previous item links.

Start with the a folder, some content, and a collection.

>>> folder
<ATFolder at /plone/Members/test_user_1_>
>>> folder.contentValues()
[<ATTopic at /plone/Members/test_user_1_/foo-topic-title>,
 <ATNewsItem at /plone/Members/test_user_1_/foo-news-item-title>,
 <ATDocument at /plone/Members/test_user_1_/bar-page-title>,
 <ATNewsItem at /plone/Members/test_user_1_/baz-news-item-title>,
 <ATNewsItem at
  /plone/Members/test_user_1_/qux-baz-news-item-title>]

One item is a page and so doesn’t show up in the collection listing.

>>> folder['foo-topic-title'].queryCatalog(full_objects=True)
[<ATNewsItem at /plone/Members/test_user_1_/foo-news-item-title>,
 <ATNewsItem at /plone/Members/test_user_1_/baz-news-item-title>,
 <ATNewsItem at
  /plone/Members/test_user_1_/qux-baz-news-item-title>,
 <ATNewsItem at
  /plone/news/blah-news-item-title>]

Next/previous navigation is enabled for the folder but not for the topic.

>>> folder.getNextPreviousEnabled()
True
>>> folder['foo-topic-title'].getNextPreviousEnabled()
False

Open a browser at the folder.

>>> from Products.Five.testbrowser import Browser
>>> browser = Browser()
>>> browser.handleErrors = False
>>> browser.open(folder.absolute_url())

Visit one of the news items, the next link points to the next item in the folder but not the next item in the collection.

>>> browser.getLink('Foo News Item Title').click()
>>> browser.getLink('Next')
<Link text='Next: Bar Page Title Right arrow[IMG]'
url='http://nohost/plone/Members/test_user_1_/bar-page-title'>

Open a browser, log in as some one who can enable the next/previous navigation for the collection, and do so.

>>> from Products.PloneTestCase import ptc
>>> owner_browser = Browser()
>>> owner_browser.handleErrors = False
>>> owner_browser.open(folder['foo-topic-title'].absolute_url())
>>> owner_browser.getLink('Log in').click()
>>> owner_browser.getControl(
...     'Login Name').value = ptc.portal_owner
>>> owner_browser.getControl(
...     'Password').value = ptc.default_password
>>> owner_browser.getControl('Log in').click()
>>> owner_browser.getLink('Edit').click()
>>> owner_browser.getControl(
...     'Enable next previous navigation').selected = True
>>> owner_browser.getControl('Save').click()
>>> print owner_browser.contents
<...
...Changes saved...

Now that next/previous navigation is enabled, visiting the collection listing will set the cookie.

>>> browser.open(folder.absolute_url())
>>> browser.headers['set-cookie']
'nextprev.collection="/plone/Members/test_user_1_/foo-topic-title";
Path=/, nextprev.form="test="; Path=/'

Visit an item again and now the next link will be the next item in the collection.

>>> browser.getLink('Foo News Item Title').click()
>>> browser.getLink('Next')
<Link text='Next: Baz News Item Title Right arrow[IMG]'
url='http://nohost/plone/Members/test_user_1_/baz-news-item-title'>

If the folder listing is visited again, the next/previous links reflect the folder contents instead of the collection results.

>>> browser.open(folder.absolute_url()+'/folder_listing')
>>> browser.headers['set-cookie']
'nextprev.collection="deleted"; Path=/; Expires=Wed,
31-Dec-97 23:59:59 GMT; Max-Age=0, nextprev.form="deleted";
Path=/; Expires=Wed, 31-Dec-97 23:59:59 GMT; Max-Age=0'

>>> browser.getLink('Foo News Item Title').click()
>>> browser.getLink('Next')
<Link text='Next: Bar Page Title Right arrow[IMG]'
url='http://nohost/plone/Members/test_user_1_/bar-page-title'>

Search criteria submitted in the request are also preserved in the cookies so that the next/previous links will reflect the correct result sets.

>>> browser.open(folder.absolute_url()+'?SearchableText=baz')
>>> browser.getLink('Baz News Item Title').click()
>>> browser.getLink('Previous')
Traceback (most recent call last):
LinkNotFoundError
>>> browser.getLink('Next')
<Link text='Next: Qux Baz News Item Title Right arrow[IMG]'
url='http://nohost/plone/Members/test_user_1_/qux-baz-news-item-title'>

Items outside the current set can be safely viewed.

>>> browser.open(folder['foo-news-item-title'].absolute_url())
>>> browser.getLink('Previous')
Traceback (most recent call last):
LinkNotFoundError
>>> browser.getLink('Next')
Traceback (most recent call last):
LinkNotFoundError

A topic which is contained in a folder but is not in the current set can also be safely viewed.

>>> browser.open(folder.absolute_url())
>>> browser.getLink('Previous')
Traceback (most recent call last):
LinkNotFoundError
>>> browser.getLink('Next')
Traceback (most recent call last):
LinkNotFoundError

Though next/previous navigation is not available on large folders, the next/previous links will still be rendered when a collection lists items inside a large folder.

>>> browser.open(folder.absolute_url())
>>> browser.getLink('Blah News Item Title').click()
>>> browser.getLink('Previous')
<Link text='Left arrow[IMG] Previous: Qux Baz News Item Title'
url='http://nohost/plone/Members/test_user_1_/qux-baz-news-item-title'>
>>> browser.getLink('Next')
Traceback (most recent call last):
LinkNotFoundError