What is pagination?
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This module helps dividing large lists of items into pages. The user is shown one page at a time and
can navigate to other pages. Imagine you are offering a company phonebook and let the user search
the entries. If the search result contains 23 entries but you may want to display no more than 10
entries at once. The first page contains entries 1-10, the second 11-20 and the third 21-23. See the
documentation of the "Page" class for more information.
How do I use this module?
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The paginate module contains extensive in-line documentation with examples.
Concerning WebHelpers
-----------------------
This is a standalone module. Former versions were included in the WebHelpers Python module as
webhelpers.paginate and were tightly coupled with the WebHelpers and the Pylons web framework. This
version aims to be useful independent of any web framework.
Subclassing Page()
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This module supports pagination through list-like objects. To paginate though other types of objects
you can subclass the paginate.Page() class and provide a wrapper class that defines how to access
elements of that special collection.
You can find examples in other paginate_* modules like paginate_sqlalchemy. Basically you would have
to provide a class that implements the __init__, __getitem__ and __len__ methods.
Example::
class SqlalchemyOrmWrapper(object):
"""Wrapper class to access elements of a collection."""
def __init__(self, obj):
self.obj = obj
def __getitem__(self, range):
# Return a range of objects of an sqlalchemy.orm.query.Query object
return self.obj[range]
def __len__(self):
# Count the number of objects in an sqlalchemy.orm.query.Query object
return self.obj.count()
Then you can create your own Page class that uses the above wrapper class::
class SqlalchemyOrmPage(paginate.Page):
"""A pagination page that deals with SQLAlchemy ORM objects."""
def __init__(self, *args, **kwargs):
super(SqlalchemyOrmPage, self).__init__(*args, wrapper_class=SqlalchemyOrmWrapper, **kwargs)
As you can see it does not do much. It basically calls paginate.Page.__init__ and adds
wrapper_class=SqlalchemyOrmWrapper as an argument. The paginate.Page instance will use that wrapper
class to access the elements.