Hi I want to enable web pagination that used to work and it broke during an update to the environment or my implementation (not sure which). I want to paginate a list ordered by GAE Since objects tend to have a "natural ordering" ie time, numbers, words etc could this code be already available somewhere usable? I tried doing something like the example from Joey G that Google listed here: http://code.google.com/appengine/articles/paging.html My effort that takes the parameter called bookmark from the URL query:
next = None
bookmark = self.request.get("bookmark")
category = self.request.get('cg')#category parameter
if bookmark:
bookmark = datetime.strftime(bookmark[:-7], "%Y-%m-%d %H:%M:%S")
else:
bookmark = datetime.strftime(datetime.now(), "%Y-%m-%d %H:%M:%S")
if cg:
articles = Articles.all().filter("category =", cg).filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
It used to work and now the paging is broken, perhaps because I don't completely understand how to handle the modified and datetime objects. Could you help me on the way? The URL to my use case is www.koolbusiness.com/li Thanks
EDIT/UPDATE: Here's the current code that displays the list page. It only uses IN at a few places so supposedly it could get rewritten to work without IN the difficulty is that it branches so much due the the many combinations possible ie searching with or with nocategory, category with or with no search and also geospatially but I don't think that I'm trying something impossible it's just that a need to learn more python (there is lambda programming involved that I only pasted in and don't fully grasp) and get a clearer structure when all the combinations are handled.
class I18NListPage(FBBaseHandler,I18NHandler):
def get(self, cursor=None, limit=60, PAGESIZE = 10, twittername = None):
client = OAuthClient('twitter', self)
if client.get_cookie():
info = client.get('/account/verify_credentials')
twittername = info['screen_name']
if (users.is_current_user_admin()):
timeline = datetime.now () - timedelta (days = limit)
else:
timeline = datetime.now () - timedelta (days = limit)
logo = ''
if util.get_host().endswith('.br'):
cookie_django_language = 'pt-br'
logo = 'montao'
translation.activate(cookie_django_language)
self.request.COOKIES['django_language'] = cookie_django_language
dispatch= 'template/montaoli.html'
else:
cookie_django_language = self.request.get('cookie_django_language', '') if self.request.get('cookie_django_language', '') else self.request.get('hl', '')
dispatch= 'template/li.html'
if cookie_django_language:
if cookie_django_language == 'unset':
del self.request.COOKIES['django_language']
else:
self.request.COOKIES['django_language'] = cookie_django_language
self.reset_language()
next = None
bookmark = self.request.get("bookmark")
if not bookmark:
bookmark = = str(time.time())
category = self.request.get('cg')
q = self.request.get('q').encode("utf-8")
w = self.request.get('q')
cg = self.request.get('cg')
t = self.request.get('t')
f = self.request.get('f')
if cg and not t and not q and not f:#category without search
ads = Ad.all().filter("category =", cg).filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
elif q and not t and not cg and not f:#search without category
ads = Ad.all().search(self.request.get('q')).filter("published =", True)
ads = filter(lambda x: x.modified > timeline, ads)
ads = filter(lambda x: x.modified <= bookmark, ads)
ads = ads[:PAGESIZE+1]
ads = sorted(ads, key=lambda x: x.modified, reverse=True)
#iterate list keeping elements that are on timeline newer than bookmark
elif q and not t and cg and not f:
ads = Ad.all().search(q).filter("type =", 's').filter("category =", cg).filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
elif t and not f:
ads = Ad.all().filter("type =", 'w').filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
elif f == 'c':
ads = Ad.all().filter("company_ad =", True).filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
elif f == 'p':
ads = Ad.all().filter("company_ad =", False).filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
else:
if util.get_host().find('onta') > 1:
ads = Ad.all().filter("modified >", timeline).filter("published =", True).filter("url IN", ['www.montao.com.br','montao']).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
else:
ads = Ad.all().filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
if util.get_host().find('onta') > 1 and f == 'c':
ads = Ad.all().filter("company_ad =", True).filter("modified >", timeline).filter("published =", True).filter("url IN", ['www.montao.com.br','montao']).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
elif util.get_host().find('onta') > 1 and f == 'p':
ads = Ad.all().filter("company_ad =", False).filter("modified >", timeline).filter("published =", True).filter("url IN", ['www.montao.com.br','montao']).filter("modified <=", bookmark ).order("-modified").fetch(PAGESIZE+1)
if self.request.get('lat'):
m=int(self.request.get('r')) if self.request.get('r') else 804670
logging.info(m)
lat = self.request.get('lat')
lon = self.request.get('lon') if self.request.get('lon') else self.request.get('lng')
ads = Ad.proximity_fetch(Ad.all().filter("modified >", timeline).filter("published =", True).filter("modified <=", bookmark ).order("-modified") ,db.GeoPt(lat, lon),max_results=PAGESIZE+1, max_distance=m)
ads = sorted(ads, key=lambda x: x.modified, reverse=True)
if ads and len(ads) == PAGESIZE+1:
next = ads[-1].modified
ads = ads[:PAGESIZE]
template_values = {'twittername':twittername,'request':self.request,'lat':self.request.get('lat'),'lon':self.request.get('lon'),'q':q,'w':w,'cg':cg,'t':t,'logo':logo,'ads':ads, 'next':next, 'user':users.get_current_user(), 'bookmark':bookmark,'q':q, 'user_url': users.create_logout_url(self.request.uri) if users.get_current_user() else 'login',
'cg':category,'admin':users.is_current_user_admin(),}
template_values.update(dict(current_user=self.current_user, facebook_app_id=FACEBOOK_APP_ID))
path = os.path.join(os.path.dirname(__file__), dispatch)
self.response.out.write(template.render(path, template_values))
UPDATE 2: I tried using the django paginator class from paginator import Paginator, InvalidPage, EmptyPage in this this case the following code actually pages the data set:
articles = Articles.all()
paginator = Paginator(articles,PAGESIZE)
articles = paginator.page(page)
so I find this solution tempting since it's so easy and readable and hope that you can comment onwards.
