I am looking for how to do validation on Google App Engine and I have found only how to do it using Django framework. Ok Django approach is ok but if I have one form and this form have data from few tables what then???
I can not do it like this:
class Item(db.Model):
name = db.StringProperty()
quantity = db.IntegerProperty(default=1)
target_price = db.FloatProperty()
priority = db.StringProperty(default='Medium',choices=[
'High', 'Medium', 'Low'])
entry_time = db.DateTimeProperty(auto_now_add=True)
added_by = db.UserProperty()
class ItemForm(djangoforms.ModelForm):
class Meta:
model = Item
exclude = ['added_by']
class MainPage(webapp.RequestHandler):
def get(self):
self.response.out.write('<html><body>'
'<form method="POST" '
'action="/">'
'<table>')
# This generates our shopping list form and writes it in the response
self.response.out.write(ItemForm())
self.response.out.write('</table>'
'<input type="submit">'
'</form></body></html>')
def post(self):
data = ItemForm(data=self.request.POST)
if data.is_valid():
# Save the data, and redirect to the view page
entity = data.save(commit=False)
entity.added_by = users.get_current_user()
entity.put()
self.redirect('/items.html')
else:
# Reprint the form
self.response.out.write('<html><body>'
'<form method="POST" '
'action="/">'
'<table>')
self.response.out.write(data)
self.response.out.write('</table>'
'<input type="submit">'
'</form></body></html>')
Is any easy way to validate form which contain data from few tables or I have to code it alone?
Looks like you're using webapp; I suggest your look at some other 'light-weight' choices for form validation. Pick one that you like the layout / syntax of. You'll be able to define complex 'nested' relationships if needed.
FormEncode
Formish
Deform
WTForms has a GAE component WTForms
WTForms now includes support for AppEngine fields as well as auto-form generation. The form class can be used as it is or serve as a base for extended form classes, which can then mix non-model related fields, subforms with other model forms, among other possibilities.
Related
Not sure if on the title I should have said parent values or ancestors, but here is what I am trying to do.
I am learning to use Python in Google App Engine. While I am reviewing the content of this page in the Guestbook tutorial, I was wondering if I could enhance it by listing all possible guestbooks created.
To give a bit of context, this is how the sample code works. The application renders a page that allows you to create a guestbook entry, as well as switching/creating new guestbooks for current or future entries. I thought it would be simple to add the ability to list all currently stored guestbooks to dynamically generate a list of links to see each one.
I thought this was very simple, but I am trying and I can't figure it out. How do I query the datastore to give me a list of all the "guestbooks" available so I can build the links dynamically? If the guestbook is called guestbook_2 the url looks like this "?guestbook_name=guestbook_2".
Here is the code of the application (I added the string "INSERT LIST HERE" where I want to addd the list of links I just mentioned):
import cgi
import urllib
from google.appengine.api import users
from google.appengine.ext import ndb
import webapp2
MAIN_PAGE_FOOTER_TEMPLATE = """\
<form action="/sign?%s" method="post">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><input type="submit" value="Sign Guestbook"></div>
</form>
<hr>
<form>Guestbook name (you can create your own guestbook here):
<input value="%s" name="guestbook_name">
<input type="submit" value="switch">
</form>
%s
<br><br>
List of guestbooks: %s
</body>
</html>
"""
DEFAULT_GUESTBOOK_NAME = 'default_guestbook'
# We set a parent key on the 'Greetings' to ensure that they are all in the same
# entity group. Queries across the single entity group will be consistent.
# However, the write rate should be limited to ~1/second.
def guestbook_key(guestbook_name=DEFAULT_GUESTBOOK_NAME):
"""Constructs a Datastore key for a Guestbook entity with guestbook_name."""
return ndb.Key('Guestbook', guestbook_name)
class Greeting(ndb.Model):
"""Models an individual Guestbook entry with author, content, and date."""
author = ndb.UserProperty()
content = ndb.StringProperty(indexed=False)
date = ndb.DateTimeProperty(auto_now_add=True)
class MainPage(webapp2.RequestHandler):
def get(self):
self.response.write('<html><body>')
guestbook_name = self.request.get('guestbook_name',
DEFAULT_GUESTBOOK_NAME)
# Ancestor Queries, as shown here, are strongly consistent with the High
# Replication Datastore. Queries that span entity groups are eventually
# consistent. If we omitted the ancestor from this query there would be
# a slight chance that Greeting that had just been written would not
# show up in a query.
greetings_query = Greeting.query(
ancestor=guestbook_key(guestbook_name)).order(-Greeting.date)
greetings = greetings_query.fetch(10)
for greeting in greetings:
if greeting.author:
self.response.write(
'<b>%s</b> wrote:' % greeting.author.nickname())
else:
self.response.write('An anonymous person wrote:')
self.response.write('<blockquote>%s</blockquote>' %
cgi.escape(greeting.content))
if users.get_current_user():
url = users.create_logout_url(self.request.uri)
url_linktext = 'Logout'
else:
url = users.create_login_url(self.request.uri)
url_linktext = 'Login'
# Write the submission form and the footer of the page
sign_query_params = urllib.urlencode({'guestbook_name': guestbook_name})
self.response.write(MAIN_PAGE_FOOTER_TEMPLATE %
(sign_query_params,
cgi.escape(guestbook_name),
url,
url_linktext,
"INSERT LIST HERE"
))
class Guestbook(webapp2.RequestHandler):
def post(self):
# We set the same parent key on the 'Greeting' to ensure each Greeting
# is in the same entity group. Queries across the single entity group
# will be consistent. However, the write rate to a single entity group
# should be limited to ~1/second.
guestbook_name = self.request.get('guestbook_name',
DEFAULT_GUESTBOOK_NAME)
greeting = Greeting(parent=guestbook_key(guestbook_name))
if users.get_current_user():
greeting.author = users.get_current_user()
greeting.content = self.request.get('content')
greeting.put()
query_params = {'guestbook_name': guestbook_name}
self.redirect('/?' + urllib.urlencode(query_params))
application = webapp2.WSGIApplication([
('/', MainPage),
('/sign', Guestbook),
], debug=True)
Just store the guestbook name somewhere, or the easiest thing is you can fetch all the Greeting's key to get the parent, something like
guestbooks = [greeting.key().parent().name() for greeting in Greeting.all(keys_only=True)]
I'm implementing a user filter system on a website. Users are to be able to select 'categories' and 'packages' of interest to them and have the matching data presented when they log in. Both sets of data will come from HTML select forms eg. Categories: 'null pointers', 'dead code'... and packages 'package_x', 'package_y', 'package_z'...
My question is about the best way to store this list information in a database (I am using Django and PostgresSQL).
My initial thought is to have a table like this:
user_id - one to one field
categories - textfield - store json data
packages - textfield - store json data
Is there a better way to be doing this?
I would go the route of using a user profile with categories and packages being many to many fields.
In models.py
from django.contrib.auth.models import User
class Category(models.Model):
name = models.CharField(max_length=255)
class Package(models.Model):
name = models.CharField(max_length=255)
class UserProfile(models.Model):
user = models.ForiegnKey(User)
categories = models.ManyToManyField(Category)
packages = models.ManyToManyField(Package)
In admin.py
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth.models import User
class CustomUserAdmin(UserAdmin):
inlines = [UserProfile]
#filter_horizontal = ('',) #Makes the selection a bit more friendly
admin.site.unregister(User)
admin.site.register(User, CustomUserAdmin)
In views.py
user_with_profile = User.objects.get(pk=user_id).get_profile()
All that being said. Django 1.5 will replace the user profile with being able to use a configurable user model.
I have a Django-tastypie resource that represents a banner and has a field called impression that I increment whenever the banner appears on the site.
class BannerResource(ModelResource):
owner = fields.ForeignKey('advertisment.api.AdvertiserResource', 'owner', full=True)
class Meta:
queryset = Banner.objects.all()
resource_name = 'banner'
authorization = Authorization()
I would like to get the banner that has the minimum impression, in the official documentation there is nothing like
filtering = {'impressions': ('min',)}
I'm using BackboneJS in the front end and I could get all the banners with Backbone collection and do the filtering with JavaScript but I'm looking for a quicker way to do it.
Any ideas?
Thanks
If you'd like to retrieve banners with number of impressions greater than X you need to things. For one you need to define possible filtering operations on your resource like so (given your model has impressions field):
class BannerResource(ModelResource):
owner = fields.ForeignKey('advertisment.api.AdvertiserResource', 'owner', full=True)
class Meta:
queryset = Banner.objects.all()
resource_name = 'banner'
authorization = Authorization()
filtering = { 'impressions' : ALL }
for available options take a look at Tastypie's documentation on filtering.
Then if you made the following request:
GET http://<your_host>/v1/banners?impressions__gte=X
you should get what you need.
Here are model and form classes from example:
http://code.google.com/appengine/articles/djangoforms.html
class Item(db.Model):
name = db.StringProperty()
quantity = db.IntegerProperty(default=1)
target_price = db.FloatProperty()
priority = db.StringProperty(default='Medium',choices=[
'High', 'Medium', 'Low'])
entry_time = db.DateTimeProperty(auto_now_add=True)
added_by = db.UserProperty()
class ItemForm(djangoforms.ModelForm):
class Meta:
model = Item
exclude = ['added_by']
It will be rendered as table rows.
Can I change how they will be rendered (change width or make it to be list instead of table row or anything…)?
Take a look at the Django forms docs, here. The docs are for 1.0, but most of it applies to the 0.91 version bundled with App Engine, too.
The short answer to your question: form.as_p will generate an HTML representation of the form as a series of <p> tags, while form.as_ul will generate a series of <ul> tags and form.as_table will generate a table.
i'm experimenting with django and the builtin admin interface.
I basically want to have a field that is a drop down in the admin UI. The drop down choices should be all the directories available in a specified directory.
If i define a field like this:
test_folder_list = models.FilePathField(path=/some/file/path)
it shows me all the files in the directory, but not the directories.
Does anyone know how i can display the folders?
also i tried doing
test_folder_list = models.charField(max_length=100, choices=SOME_LIST)
where SOME_LIST is a list i populate using some custom code to read the folders in a directory. This works but it doesn't refresh. i.e. the choice list is limited to a snapshot of whatever was there when running the app for the first time.
thanks in advance.
update:
after some thinking and research i discovered what i want may be to either
1. create my own widget that is based on forms.ChoiceField
or
2. pass my list of folders to the choice list when it is rendered to the client
for 1. i tried a custom widget.
my model looks like
class Test1(models.Model):
test_folder_ddl = models.CharField(max_length=100)
then this is my custom widget:
class FolderListDropDown(forms.Select):
def __init__(self, attrs=None, target_path):
target_folder = '/some/file/path'
dir_contents = os.listdir(target_folder)
directories = []
for item in dir_contents:
if os.path.isdir(''.join((target_folder,item,))):
directories.append((item, item),)
folder_list = tuple(directories)
super(FolderListDropDown, self).__init__(attrs=attrs, choices=folder_list)
then i did this in my modelForm
class test1Form(ModelForm):
test_folder_ddl = forms.CharField(widget=FolderListDropDown())
and it didn't seem to work.What i mean by that is django didn't want to use my widget and instead rendered the default textinput you get when you use a CharField.
for 2. I tried this in my ModelForm
class test1Form(ModelForm):
test_folder_ddl = forms.CharField(widget=FolderListDropDown())
test_folder_ddl.choices = {some list}
I also tried
class test1Form(ModelForm):
test_folder_ddl = forms.ChoiceField(choices={some list})
and it would still render the default char field widget.
Anyone know what i'm doing wrong?
Yay solved. after beating my head all day and going through all sorts of examples by people i got this to work.
basically i had the right idea with #2. The steps are
- Create a ModelForm of our model
- override the default form field user for a models.CharField. i.e. we want to explcitly say use a choiceField.
- Then we have to override how the form is instantiated so that we call the thing we want to use to generate our dynamic list of choices
- then in our ModelAdmin make sure we explicitly tell the admin to use our ModelForm
class Test1(models.Model):
test_folder_ddl = models.CharField(max_length=100)
class Test1Form(ModelForm):
test_folder_ddl = forms.choiceField()
def __init__(self, *args, **kwargs):
super(Test1Form, self).__init__(*args, **kwargs)
self.fields['test_folder_ddl'].choices = utility.get_folder_list()
class Test1Admin(admin.ModelAdmin):
form = Test1Form
I use a generator:
see git://gist.github.com/1118279.git
import pysvn
class SVNChoices(DynamicChoice):
"""
Generate a choice from somes files in a svn repo
""""
SVNPATH = 'http://xxxxx.com/svn/project/trunk/choices/'
def generate(self):
def get_login( realm, username, may_save ):
return True, 'XXX', 'xxxxx', True
client = pysvn.Client()
client.callback_get_login = get_login
return [os.path.basename(sql[0].repos_path) for sql in client.list(self.SVNPATH)[1:]]