Pagination

[Web2Py Freak]

Hey guys ,

Anyone Used Pagination before , i have a table named "blogpost" and i
want it to view every 10 post in a page , how can i do that ??

[pbreit]

Probably have to code it. There's an example in the book.

[Bruno Rocha]

db(db.posts.id>0).select(limitby=(0,10))

http://zerp.ly/rochacbruno

[Web2Py Freak]

This is the example in the book , how can i edit it to fit my table "db.blogpost" ?

db = DAL('sqlite://primes.db')
db.define_table('prime',Field('value','integer'))
def isprime(p):
    for i in range(2,p):
        if p%i==0: return False
    return True
if len(db().select(db.prime.id))==0:
   p=2
   for i in range(1000):
       while not isprime(p): p+=1
       db.prime.insert(value=p)
       p+=1

def list_items(): if len(request.args): page=int(request.args[0]) else: page=0 items_per_page=20 limitby=(page*items_per_page,(page+1)*items_per_page+1) rows=db().select(db.prime.ALL,limitby=limitby) return dict(rows=rows,page=page,items_per_page=items_per_page)

Notice that this code selects one more item than is needed, 20+1. The extra element tells the view whether there is a next page.

Here is the "default/list_items.html" view:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

{{extend 'layout.html'}} {{for i,row in enumerate(rows):}} {{if i==items_per_page: break}} {{=row.value}}<br /> {{pass}} {{if page:}} <a href="{{=URL(args=[page-1])}}">previous</a> {{pass}} {{if len(rows)>items_per_page:}} <a href="{{=URL(args=[page+1])}}">next</a> {{pass}}

[Massimo Di Pierro]

You can do something like this:

class Paginator(DIV):
items_per_page = 10
records = 100
def limitby(self):
from gluon import current
page = self.page=int(current.request.vars.page or 0)
return (self.items_per_page*page,self.items_per_page*(page
+1))
def xml(self):
from gluon import current
pages,rem = divmod(self.records,self.items_per_page)
if rem: pages+=1
if self.page>0:

self.append(A('first',_href=URL(args=current.request.args,vars=dict(page=0))))
if self.page>1:

self.append(A('prev',_href=URL(args=current.request.args,vars=dict(page=self.page-1))))
if self.page<pages-2:

self.append(A('next',_href=URL(args=current.request.args,vars=dict(page=self.page
+1))))
if self.page<pages-1:

self.append(A('last',_href=URL(args=current.request.args,vars=dict(page=pages-1))))
return DIV.xml(self)

def index():
p=Paginator()
p.items_per_page=5
p.records=db(query).count()
rows = db(query).select(limitby=p.limitby())
return dict(rows=rows, paginator=p)

{{extend 'layout.html'}}
{{=SQLTABLE(rows)}}
{{=paginator}}

customize the xml function above to make it look better!

[pbreit]

Where does the class go? In a module?

I still don't fully understand "current". Is that an easy way for a module to have access to the whole current environment?

[Massimo Di Pierro]

You can put anywhere you like. If it goes in a module, you need to
import it.

Because of the new custom import and current. This is no longer a
problem.

Any module imported by a model or controller can do from gluon import
current, DIV, SQLHTML, etc. and get access to everything. current
contains current.request, current.response, current.session,
current.T, current.cache + anything your models want to pass want to
pass to the modules.