Extras

At this point our application is complete and tested. At this point you can dive right in to the User’s Guide, but there are a few extra things we can add to further demonstrate some more of Ferris’ capabilities.

Pagination

Ferris uses Components as a way of organizing commonly used functionality for Handlers. Ferris comes with a handful of built-in components and includes one for automatic pagination for list methods.

It’s pretty easy to use. First import it:

from ferris.components.pagination import Pagination

Then add it to our handler’s component list and set the limit:

@scaffold
class Posts(EasyHandler):
    components = [Pagination]
    paginate_limit = 5

If you open up http://localhost:8080/posts, you’ll see that it will show no more than five posts. However, we don’t currently have a way to move between pages. Luckily, the scaffolding macros can handle that.

Add this to our list.html template right before the end of the layout_content block:

{{scaffold.next_page_link()}}

Now there is a paginator at the bottom of the page.

Searching

Another useful component is search. It is slightly more difficult to use but still quite easy.

First, we need to modify our model.

Import the index and unindex functions:

from ferris.components.search import index, unindex

Add two methods:

def after_put(self, key):
    index(self)

@classmethod
def after_delete(cls, key):
    unindex(key)

These are model callbacks (covered more extensively in the User’s Guide) that will index and unindex a post whenever it is saved or deleted.

Note

Any posts created before you made this change will not be searchable until you edit and resave them.

Import the Search component and add it to our Posts handler:

from ferris.core.easy_handler import EasyHandler, scaffold, route
from ferris.components.pagination import Pagination
from ferris.components.search import Search


@scaffold
class Posts(EasyHandler):
    components = [Pagination, Search]

Now let’s add a new search action:

def search(self):
    self.components.search.search()

Import the search macros into templates/posts/list.html:

{% import 'macros/search.html' as search with context %}

Finally, add these somewhere at the top of the inside of the layout_content block:

{{search.search_filter(action='list')}}
{{search.search_info()}}

Now when we visit http://localhost:8080/posts there should be a search box from which we can search through all posts.