A douban-group-like page style

page_template.html

{% if pageobj.shownav %}
<div class="articles-control">
	{% if pageobj.showprev %}
	<span class="page-prev"><a href="/page/?start={{ pageobj.prevpage }}">PREV PAGE</a></span>
	{% endif %}
	<span class="page-number">{{pageobj.page}}</span>
	{% if pageobj.shownext %}
	<span class="page-next"><a href="/page/?start={{ pageobj.nextpage }}">NEXT PAGE</a></span>
	{% endif %}
</div>
{% endif %}

PageObj.py

class PageObj(object):
  """
  A douban group like page style
  """
  def __init__(self,pages,limit=10,start=10):
    self.pages = pages
    self.page = start/limit+1
    self.nextpage = self.page*limit
    self.prevpage = (self.page-1)*limit-limit
    if self.page*limit >= self.pages:
      self.shownext = False
    else:
      self.shownext = True
    if (self.page*limit)-limit <= 0:
      self.showprev = False
    else:
      self.showprev = True
    if self.pages <= limit:
      self.shownav = False
    else:
      self.shownav = True


class MainPage(BlogBaseHandler):
  def get(self, start=0):
    allarticles = models.Article.all()
    start = self.param("start")
    if start.isdigit() is not True:
      start = 0
    pageobj = PageObj(pages=allarticles.count(),limit=10,start=int(start))
    articles = models.Article.all().order('-created').fetch(limit=10,offset=int(start))
    self.render_to_response('template/index.html', {
      'articles': articles,
      'pageobj':pageobj,
    })