Google App Engine: Kind Error - python-2.7

Following is my program
import os
import jinja2
import re
from string import letters
import webapp2
from google.appengine.ext import db
template_dir= os.path.join(os.path.dirname(__file__),'templates')
jinja_env= jinja2.Environment(loader= jinja2.FileSystemLoader(template_dir),autoescape= True)
class Handler(webapp2.RequestHandler):
def write(self,*a,**kw):
self.response.write(*a,**kw)
def render_str(self,template, **params):
t= jinja_env.get_template(template)
return t.render(params)
def render(self,template, **kw):
self.write(self.render_str(template,**kw))
def blog_key(name = "default"):
return db.Key.from_path('blogs',name)
class Post(db.Model):
title= db.StringProperty(required= True)
content= db.TextProperty(required= True)
created= db.DateTimeProperty(auto_now_add= True)
edited= db.DateTimeProperty(auto_now= True)
def render(self):
self._render_text= self.content.replace('\n', '<br>')
return render_str("blogs.html", p= self)
class BlogFront(Handler):
def get(self):
posts= db.GqlQuery("select * from posts order by desc limit 10")
self.render("front.html", posts=posts )
#for a link to the new posts created
class PostPage(Handler):
def get(self, post_id):
key= db.Key.from_path("Post", int(post_id), parent= blog_key())
post=db.get(key)
if not post:
self.error(404)
return
self.render("permalink.html", post=post)
#for new blog entries
class NewPost(Handler):
def get(self):
self.render('newpost.html')
def post(self):
title= self.request.get("title")
content= self.request.get("content")
if title and content:
p= Post(parent= blog_key(), title=title, content=content)
p.put()
self.redirect('/blogs/%s' % str(p.key().id()))
else:
error= "Please write both title and content!!"
self.render("newpost.html",title=title, content=content, error=error)
app = webapp2.WSGIApplication([
('/blog/newpost', NewPost),
('/blogs/?',BlogFront),
('/blogs/([0-9]+)',PostPage), #anything in the bracket will be passed as the parameter
], debug=True)
But when I'm trying to implement this program, I'm getting the following error:
File "C:\Users\tan31102\AppData\Local\Google\Cloud
SDK\google-cloud-sdk\platfo
rm\google_appengine\google\appengine\ext\db__init__.py", line 299, in
class_for
_kind
raise KindError('No implementation for kind \'%s\'' % kind) KindError: No implementation for kind 'posts'
Can someone please help me with this.

Your gql uses post in plural form - "posts"
select * from posts order by desc limit 1
while the db.Model class you have declared uses posts in singular form (Post)
class Post(db.Model):
You need to stick with either form. Also you should consider using ndb.Model instead of db.Model as stated in the docs

You have to import the model definition in the Py file that uses it. This causes the KindError.
from posts import posts
or something similar.
It sounds like you are trying to load a posts entity from a session without importing the posts model first.
To ensure that posts is available when the session middleware runs, you must import the posts model in your script.

Related

Django models __unicode__: How to return a value containing localized datetimes?

I have a localized Django App, localisation works well and the configuration is ok…
For forms needs, I use __unicode__ method for model to render ModelChoiceFields, but how do I format localized date in the unicode return?
In this method I have no access to current timezone, how to display my TimeSpanList correctly to my users? Currently, it displays UTC. I tryed django.template.defaultfilters.date and Simon Charette's django.utils.formats.localize which didn't helped as they probably lacked contextual data…
class TimeSpan(models.Model):
start = models.DateTimeField(_("start"))
end = models.DateTimeField(_("end"))
def __unicode__(self):
return u"from UTC:{0} to UTC:{1}".format(self.start, self.end)
class TimeSpanChooserForm(forms.Form):
time_span = forms.ModelChoiceField(
label=_("time span"), queryset=TimeSpan.objects.all())
def __init__(self, *args, **kwargs):
self.request = kwargs.pop("request", None)
super(TimeSpanChooserForm, self).__init__(*args, **kwargs)
How to know current locale without current request object to localize those datetimes? (If there is a way)
note: to me __unicode__ seems like the only way to display entries in ModelChoiceField.
note 2: to me, Yuji 'Tomita' Tomita comment is the best current answer but it lacks a usable exemple…
Thanks for reminding me about this question. It's a bit involved for a complete answer.
I've created a demo method that shows this in action. Run test() to see output.
The remaining challenge is getting the client timezone. This will probably be done with some JavaScript that adds a parameter to your GET/POST or adds a custom header to be read in the view.
Since this is an unknown, I just stubbed it out with a method that returns a random time zone. You should update it to reflect your client timezone retrieval method.
Here's a self documenting example:
Models
from django.utils.formats import localize
class TimeSpan(models.Model):
start = models.DateTimeField("start")
end = models.DateTimeField("end")
def __unicode__(self):
return u"from UTC:{0} to UTC:{1}".format(self.start, self.end)
Form
from django import forms
class TimeSpanChooserForm(forms.Form):
time_span = forms.ModelChoiceField(
label=("time span"), queryset=TimeSpan.objects.all())
def __init__(self, *args, **kwargs):
# get request and TZ from view. This is a special form..
self.request = kwargs.pop("request", None)
self.tz = kwargs.pop('tz', None)
super(TimeSpanChooserForm, self).__init__(*args, **kwargs)
# modify the choices attribute to add custom labels.
self.fields['time_span'].choices = [
self.make_tz_aware_choice(self.request, timespan) for timespan in self.fields['time_span'].queryset
]
def make_tz_aware_choice(self, request, timespan):
""" Generate a TZ aware choice tuple.
Must return (value, label). In the case of a ModelChoiceField, (instance id, label).
"""
start = timespan.start.replace(tzinfo=self.tz)
end = timespan.end.replace(tzinfo=self.tz)
label = "From {tz} {start} to: {tz} {end}".format(
start=start,
end=end,
tz=self.tz,
)
return (timespan.id, label)
View
import random
import pytz
from django import http
from django import template
def view(request):
""" Render a form with overridden choices respecting TZ
"""
def get_tz_from_request(request):
""" Get the client timezone from request.
How you do this is up to you. Likely from JS passed as a parmeter.
"""
random_timezone = random.choice(pytz.all_timezones)
return pytz.timezone(random_timezone)
form = TimeSpanChooserForm(request.POST or None, request=request, tz=get_tz_from_request(request))
ctx = template.Context({
'form': form,
})
rendered_template = template.Template("{{ form }}").render(ctx)
return http.HttpResponse(rendered_template)
def test():
from django.test import RequestFactory
rf = RequestFactory()
r = rf.get('/')
for i in range(10):
print str(view(r))
You can use the django.utils.formats.localize function.
from django.db import models
from django.utils.formats import localize
from django.utils.translation import ugettext
class TimeSpan(models.Model):
start = models.DateTimeField(_('start'))
end = models.DateTimeField(_('end'))
def __unicode__(self):
return ugettext("from %(start)s to %(end)s") % {
'start': localize(self.start),
'end': localize(self.end),
}
You can test the following work with those manipulation.
from django.utils import timezone
from django.utils.translation import override
with override('fr'):
print(TimeSpan(start=timezone.now(), end=timezone.now()))
with override('en'):
print(TimeSpan(start=timezone.now(), end=timezone.now()))
Both should display different formating.
If you want to make sure dates are displayed in a specific timezone you must make sure USE_TZ = True in your settings and set the TIME_ZONE setting to the one you want to use. You can set this timezone per request by using a middleware that calls django.utils.timezone.activate with the desired timezone.
You can also use the django-sundial package which takes care of this for you.
Try this:
def __unicode__(self):
return u'%s %s'%(self.start,self.end)
Buy using this it will return combined start and end datetime objects.This worked for me

A Category model which creates proxy models for related model admin

So I'm having a bit of trouble with trying to create a model that will define dynamic proxy models that manage a related model in the admin site. I know that sentence was confusing, so I'll just share my code instead.
models.py
class Cateogry(models.Model):
name = models.CharField(...)
class Tag(models.Model):
name = models.CharField(...)
category = models.ForeignKey(Cateogry)
What I want to achieve is that in the admin site, instead of having one ModelAdmin for the Tag model, for each category I will have a modeladmin for all related tags. I have achieved this using this answer. Say I have a category named A:
def create_modeladmin(modeladmin, model, name = None):
class Meta:
proxy = True
app_label = model._meta.app_label
attrs = {'__module__': '', 'Meta': Meta}
newmodel = type(name, (model,), attrs)
admin.site.register(newmodel, modeladmin)
return modeladmin
class CatA(TagAdmin):
def queryset(self, request):
qs = super(CatA, self).queryset(request)
return qs.filter(cateogry = Cateogry.objects.filter(name='A'))
create_modeladmin(CatA, name='CategoryAtags', model=Tag)
But this is not good enough, because obviously I still need to manually subclass the TagAdmin model and then run create_modeladmin. What I need to do, is loop over all Category objects, for each one create a dynamic subclass for Tagadmin (named after the category), then create a dynamic proxy model from that, and this is where my head starts spinning.
for cat in Category.objects.all():
NewSubClass = #somehow create subclass of TagAdmin, the name should be '<cat.name>Admin' instead of NewSubClass
create_modeladmin(NewSubClass, name=cat.name, model=Tag)
Any guidance or help would be much appreciated
Dynamic ModelAdmins don't work well together with the way admin registeres models.
I suggest to create subviews in the CategoryAdmin.
from django.conf.urls import patterns, url
from django.contrib import admin
from django.contrib.admin.options import csrf_protect_m
from django.contrib.admin.util import unquote
from django.core.urlresolvers import reverse
from demo_project.demo.models import Category, Tag
class TagAdmin(admin.ModelAdmin):
# as long as the CategoryTagAdmin class has no custom change_list template
# there needs to be a default admin for Tags
pass
admin.site.register(Tag, TagAdmin)
class CategoryTagAdmin(admin.ModelAdmin):
""" A ModelAdmin invoked by a CategoryAdmin"""
read_only_fields = ('category',)
def __init__(self, model, admin_site, category_admin, category_id):
self.model = model
self.admin_site = admin_site
self.category_admin = category_admin
self.category_id = category_id
super(CategoryTagAdmin, self).__init__(model, admin_site)
def queryset(self, request):
return super(CategoryTagAdmin, self).queryset(request).filter(category=self.category_id)
class CategoryAdmin(admin.ModelAdmin):
list_display = ('name', 'tag_changelist_link')
def tag_changelist_link(self, obj):
info = self.model._meta.app_label, self.model._meta.module_name
return '<a href="%s" >Tags</a>' % reverse('admin:%s_%s_taglist' % info, args=(obj.id,))
tag_changelist_link.allow_tags = True
tag_changelist_link.short_description = 'Tags'
#csrf_protect_m
def tag_changelist(self, request, *args, **kwargs):
obj_id = unquote(args[0])
info = self.model._meta.app_label, self.model._meta.module_name
category = self.get_object(request, obj_id)
tag_admin = CategoryTagAdmin(Tag, self.admin_site, self, category_id=obj_id )
extra_context = {
'parent': {
'has_change_permission': self.has_change_permission(request, obj_id),
'opts': self.model._meta,
'object': category,
},
}
return tag_admin.changelist_view(request, extra_context)
def get_urls(self):
info = self.model._meta.app_label, self.model._meta.module_name
urls= patterns('',
url(r'^(.+)/tags/$', self.admin_site.admin_view(self.tag_changelist), name='%s_%s_taglist' % info )
)
return urls + super(CategoryAdmin, self).get_urls()
admin.site.register(Category, CategoryAdmin)
The items in the categories changelist have an extra column with a link made by the tag_changelist_link pointing to the CategoryAdmin.tag_changelist. This method creates a CategoryTagAdmin instance with some extras and returns its changelist_view.
This way you have a filtered tag changelist on every category. To fix the breadcrumbs of the tag_changelist view you need to set the CategoryTagAdmin.change_list_template to a own template that {% extends 'admin/change_list.html' %} and overwrites the {% block breadcrumbs %}. That is where you will need the parent variable from the extra_context to create the correct urls.
If you plan to implement a tag_changeview and tag_addview method you need to make sure that the links rendered in variouse admin templates point to the right url (e.g. calling the change_view with a form_url as paramter).
A save_model method on the CategoryTagAdmin can set the default category when adding new tags.
def save_model(self, request, obj, form, change):
obj.category_id = self.category_id
super(CategoryTagAdmin, self).__init__(request, obj, form, change)
If you still want to stick to the apache restart aproach ... Yes you can restart Django. It depends on how you are deploying the instance.
On an apache you can touch the wsgi file that will reload the instance os.utime(path/to/wsgi.py.
When using uwsgi you can use uwsgi.reload().
You can check the source code of Rosetta how they are restarting the instance after the save translations (views.py).
So I found a half-solution.
def create_subclass(baseclass, name):
class Meta:
app_label = 'fun'
attrs = {'__module__': '', 'Meta': Meta, 'cat': name }
newsub = type(name, (baseclass,), attrs)
return newsub
class TagAdmin(admin.ModelAdmin):
list_display = ('name', 'category')
def get_queryset(self, request):
return Tag.objects.filter(category = Category.objects.filter(name=self.cat))
for cat in Category.objects.all():
newsub = create_subclass(TagAdmin, str(cat.name))
create_modeladmin(newsub, model=Tag, name=str(cat.name))
It's working. But every time you add a new category, you need to refresh the server before it shows up (because admin.py is evaluated at runtime). Does anyone know a decent solution to this?

django dynamic form generation

say I have a model such:
class ComponentLength(models.Model):
component_name = models.CharField(max_length=155)
length1 = models.IntegerField()
length2 = models.IntegerField()
length3 = models.IntegerField()
length4 = models.IntegerField()
Now I have a form for the user to select a component, and on the next page I want to display 4 checkboxes for the various length options, which are different for different components.
What is the best way in Django to generate the form with these checkboxes based on the component name (accessible in session data) already selected by the user.
Any help much appreciated.
You could use a normal django form and change its fields upon instantiation, in the init method. Something like this:
class SecondForm(forms.Form):
def __init__(self, *args, **kwargs):
super(SecondForm, self).__init__(*args, **kwargs)
try:
#get the object, something like this:
obj_ = ComponentLength.objects.get(component_name = session.get('component_name_or_whatever_you_stored'))
except:
#handle the error case, e.g:
return
self.fields['length1'] = forms.CheckboxInput(attrs={'value' : obj_.length1 })
self.fields['length2'] = forms.CheckboxInput(attrs={'value' : obj_.length2 })
self.fields['length3'] = forms.CheckboxInput(attrs={'value' : obj_.length3 })
self.fields['length4'] = forms.CheckboxInput(attrs={'value' : obj_.length4 })
#Consider using a hidden input instead of polluting the session variables
#with form data
self.fields['component_length'] = forms.HiddenInput(attrs={'value' : obj_.pk})
The above code is not tested, but I expect it should work. Please let me know how it goes.
Form wizards is exactly what you need.
https://docs.djangoproject.com/en/1.7/ref/contrib/formtools/form-wizard/
See the example shown here https://docs.djangoproject.com/en/1.7/ref/contrib/formtools/form-wizard/#usage-of-namedurlwizardview
And how forms are defined here https://docs.djangoproject.com/en/1.7/ref/contrib/formtools/form-wizard/#conditionally-view-skip-specific-steps
I haven't tested the code below, but it should be something similar to the following:
myapp/forms.py
from django.forms import ModelForm
from myapp.models import ComponentLength
class ComponentLengthNameForm(ModelForm):
class Meta:
model = ComponentLength
fields = ['component_name',]
class ComponentLengthChoicesForm(ModelForm):
class Meta:
model = ComponentLength
fields = ['length1', 'length2', 'length3', 'length4',]
myapp/views.py
from django.contrib.formtools.wizard.views import SessionWizardView
from django.shortcuts import render_to_response
class ComponentWizard(SessionWizardView):
def done(self, form_list, **kwargs):
return render_to_response('done.html', {
'form_data': [form.cleaned_data for form in form_list],
})
myapp/urls.py
from django.conf.urls import url, patterns
from myapp.forms import ComponentLengthNameForm, ComponentLengthChoicesForm
from myapp.views import ContactWizard
named_contact_forms = (
('name', ComponentLengthNameForm),
('length-choices', ComponentLengthChoicesForm),
)
component_wizard = ComponentWizard.as_view(named_contact_forms,
url_name='component-wizard-form-step', done_step_name='finished')
urlpatterns = patterns('',
url(r'^my-form/(?P<step>.+)/$', component_wizard, name='component-wizard-form-step'),
url(r'^my-form/$', component_wizard, name='component-wizard-form'),
)

Django: How to make a query for on object based on an M2M field (multiple selections for field on search form)

I need help coming up with an efficient way to do a search query for a set of objects, based on a M2M field. My search form is going to look something like Blue Cross Blue Shield's | eg: this image
Now, let's suppose my model looks like this:
# models.py
class Provider(models.Model)
title = models.CharField(max_length=150)
phone = PhoneNumberField()
services_offered = models.ManyToManyField(ServiceType)
def __unicode__(self):
return self.title
class ServiceCategory(models.Model):
service_category = models.CharField(max_length=30)
def __unicode__(self):
return self.service_category
class Meta(object):
verbose_name_plural = "Service Categories"
class ServiceType(models.Model):
service_type = models.CharField(max_length=30)
service_category = models.ForeignKey(ServiceCategory)
def __unicode__(self):
return u'%s | %s' % (self.service_category, self.service_type
Also, we have to keep in mind that the options that we select are subject to change, since how they display on the form is dynamic (new ServiceCategories and ServiceTypes can be added at anytime). *How should I go about constructing a query for the Provider objects, given that a person using the search form can select multiple Services_Offered?*
This is currently my HIGHLY INEFFICIENT METHOD:
#managers.py
from health.providers.models import *
from django.db.models import Q
class Query:
def __init__(self):
self.provider_objects=Provider.objects.all()
self.provider_object=Provider.objects
self.service_object=ServiceType.objects
self.category_objects=ServiceCategory.objects.all()
def simple_search_Q(self, **kwargs): #matt's learning note: **kwargs passes any dictionary
return self.provider_objects.filter(
Q(services_offered__service_type__icontains=kwargs['service']),
Q(title__icontains=kwargs['title']),
Q(state=kwargs['state']),
).distinct().order_by('title')
====================
#views.py
from django.shortcuts import render_to_response
from health.providers.models import *
from health.search.forms import *
from health.search.managers import Query #location of the query sets
from django.core.paginator import Paginator, InvalidPage, EmptyPage
from django.template import RequestContext
def simple_search(request):
if request.method == 'POST':
SimpleSearch_form = SimpleSearch(request.POST)
if SimpleSearch_form.is_valid():
request.session["provider_list"] = None
kwargs = {'title': request.POST['title'],
'service': request.POST['service'], 'state': request.POST['state'] }
provider_list = Query().simple_search_Q(**kwargs)
return pagination_results(request, provider_list)
else:
SimpleSearch_form = SimpleSearch()
return render_to_response('../templates/index.html', { 'SimpleSearch_form': SimpleSearch_form},
context_instance=RequestContext(request))
How can I make my query:
Obtain Provider objects based on selecting multiple request.POST['service']
More efficient
Thanks for any help in advanced.
Best Regards,
Matt
1: for multiple request.POST['service'], I assume you mean these are CheckBoxes.
I'd make the CheckBox values ID's, not names, and do a PK lookup.
'services_offered__pk__in': request.POST.getlist('service')
That would return all Provider objects that have ALL of the services selected.
PS: You are also using CapitalCase for instances which is very confusing. If you want your code to be readable, I highly recommend some changes to your style (don't use CapitalCase for instances or variables) and make your variables more descriptive.
SimpleSearch_form = SimpleSearch() # what is SimpleSearch?
simplesearch_form = SimpleSearchForm() # now, it's very clear what the class SimpleSearchForm is
# and the form instance is clearly a for instance.
2: making it more efficient? You could get rid of a lot of code and code separation by remove your whole Query class. Also, I don't know why you are using Q objects since you are not doing anything that would require it (like OR or OR + AND).
def simple_search(request):
if request.method == 'POST':
searchform = SimpleSearchForm(request.POST)
if searchform.is_valid():
request.session['provider_list'] = None
post = request.POST
providers = Provider.objects.filter(services_offered__pk__in=post.getlist('services'),
title=post['title'], state=post['state'])
return pagination_results(request, provider_list)
else:
searchform = SimpleSearchForm()
return direct_to_template(request, '../templates/index.html', { 'searchform': searchform})

Django 1.1.1's Feed only displays the latest item, while there are many

I've created a Feed subclass to export a simple feed of news
#urls.py
from django.conf.urls.defaults import *
from litenewz.feeds import NewsFeed
feeds = {
'news': NewsFeed,
}
urlpatterns = patterns(
'',
(r'^feeds/(?P<url>.*)/$',
'django.contrib.syndication.views.feed',
{'feed_dict': feeds}),
)
#feeds.py
from django.contrib.syndication.feeds import Feed
from litenewz.models import News
class NewsFeed(Feed):
title = 'example news'
link = 'http://example.net'
description = 'Latest Newz from example.'
item_author_name = '...'
item_author_email = '...'
item_author_link = 'http://example.net'
def items(self):
return News.objects.order_by('-time')[:15]
#models.py
from django.db import models
from django.utils.translation import ugettext as _
from datetime import datetime
class News(models.Model):
class Meta:
ordering = ('-time', )
verbose_name = _('News')
verbose_name_plural = _('News')
title = models.CharField(
_('Title'),
max_length=512)
time = models.DateTimeField(
_('Date and time'),
default=datetime.now
)
content = models.TextField(
_('Content'))
def __unicode__(self):
return self.title
#models.permalink
def get_absolute_url(self):
return ('home', (), {})
As you can see the Feed subclass' items() method returns the first 15 objects in News.objects.order_by('-time'):
def items(self):
return News.objects.order_by('-time')[:15]
Nevertheless, only one item is exported in the feed: hxxp://www.sshguard.net/litenewz/feeds/news/
Unfortunately, there are two objects of the News model:
>>> from litenewz.models import *
>>> News.objects.all()
[<News: Version 1.5 and timing>, <News: SSHGuard news>]
Any help?
I prefer not to switch to Django 1.2, unless this is strictly necessary to solve the issue described.
Update: the RSS returned indeed contains both the objects, but the RSS is not valid and thus readers such as Safari's are fooled:
http://validator.w3.org/feed/check.cgi?url=http://www.sshguard.net/litenewz/feeds/news/
Looks like it's not valid because you've not generated your guid correctly:
The validator says:
This feed does not validate.
line 25, column 83: guid values must not be duplicated within a feed:
... )</author><guid>http://www.sshguard.net/</guid></item></channel></rss>
The reason is that your get_absolute_url method on your News model returns the same thing for each News instance - do you have unique URLs for each News item? If so you should use that rather than:
def get_absolute_url(self):
return ('home', (), {})
The validation error appears to be from the <guid> element in each item of your feed. As far as I can tell, this is auto-generated from the get_absolute_url() method of the model, in your case the News model. Have you defined that method? If so, is it actually returning a distinct URL for each item?