how to resolve circular import involving haystack? - django

Haystack
haystack_signal_processor let you use custom signal processor to initiate index for certain models.
I have in my settings.py
HAYSTACK_SIGNAL_PROCESSOR='my_app.signals.MySignalProcessor'
(this imports signals.py so. this is settings -> signals)
then inside my signals.py I have
from my_app.models import my_model # to connect my_model
And my_app.models.py has from django.conf import settings
(signals -> models -> settings)
How do I resolve this circular import?

taken from https://github.com/PitonFoundation/atlas/commit/cc0abcb
Instead of importing the model on top of your signals.py file, import the models in the methods of your custom SignalProcessor using get_model:
from django.db.models.loading import get_model
class MySignalProcessor(signals.BaseSignalProcessor):
def setup(self):
MyModel = get_model('myApp', 'MyModel')
models.signals.post_save.connect(self.handle_save, sender=MyModel)

Related

I try to be able to load an image in the django admin, but I can't see it when I click

I don't know how to solve it. It's really frustrating. If you managed to help, I would be very grateful.
settings:
STATIC_URL = '/static/'
MEDIA_URL='Proyectoweb/media/'
MEDIA_ROOT=BASE_DIR / 'Proyecto/media'
url:
from django.urls import path
from ProyectoApp import views
from django.conf import settings
from django.conf.urls.static import static
urlpatterns+=static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
models:
from django.db import models
# Create your models here.
class Servicio(models.Model):
titulo=models.CharField(max_length=50)
contenido=models.CharField(max_length=50)
imagen=models.ImageField(upload_to='servicios')
created=models.DateTimeField(auto_now_add=True)
updated=models.DateTimeField(auto_now_add=True)
class Meta:
verbose_name='servicio'
verbose_name_plural='servicios'
def __str__(self):
return self.titulo
admin:
from django.contrib import admin
from .models import Servicio
# Register your models here.
class ServicioAdmin(admin.ModelAdmin):
readonly_fields=('created', 'updated')
admin.site.register(Servicio, ServicioAdmin)
For some reason, this page asks me for more details, when I think I have already given enough.
I try to be able to load an image in the django admin, but I can't see it when I click....

Flask questions about BaseConverter and __init.py__

I am trying to use a custom Baseconverter to ensure that my urls are "clean". I finally got it to work as follows:
My init.py is:
import os
from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from flask.ext.login import LoginManager
from flask.ext.openid import OpenID
from config import basedir
from slugify import slugify
app = Flask(__name__)
from werkzeug.routing import BaseConverter
class MyStringConverter(BaseConverter):
def to_python(self, value):
return value
def to_url(self, values):
return slugify(values)
app.url_map.converters['mystring'] = MyStringConverter
app.config.from_object('config')
db = SQLAlchemy(app)
lm = LoginManager()
lm.init_app(app)
lm.login_view = 'login'
oid = OpenID(app, os.path.join(basedir, 'tmp'))
from app import views, models
But if I define the MyStringConverter class and add app.url_map.converters['mystring'] = MyStringConverter at the end of the file instead, I got a LookupError: the converter 'mystring' does not exist error. Why is this?
Is this the correct way to clean up my urls? I'm not sure if I need to do anything to the to_python() method or if I am going about this the right way.

How do I add flask-admin to a Blueprint?

for example:
from flask import Flask
from flask.ext.admin import Admin, BaseView, expose
class MyView(BaseView):
#expose('/')
def index(self):
return self.render('index.html')
app = Flask(__name__)
admin = Admin(app)
admin.add_view(MyView(name='Hello'))
app.run()
but, if I need a new file, called 'views.py', how can I add a view into views.py to admin?
Do I need to use a blueprint?
For my project I actually made a child class of Blueprint that supports flask admin:
from flask import Blueprint
from flask_admin.contrib.sqla import ModelView
from flask_admin import Admin
class AdminBlueprint(Blueprint):
views=None
def __init__(self,*args, **kargs):
self.views = []
return super(AdminBlueprint, self).__init__('admin2', __name__,url_prefix='/admin2',static_folder='static', static_url_path='/static/admin')
def add_view(self, view):
self.views.append(view)
def register(self,app, options, first_registration=False):
admin = Admin(app, name='microblog', template_mode='adminlte')
for v in self.views:
admin.add_view(v)
return super(AdminBlueprint, self).register(app, options, first_registration)
For details you may like to read my blog here: http://blog.sadafnoor.me/blog/how-to-add-flask-admin-to-a-blueprint/
I am very late for this question, but anyway... My guess is that you want to use the Application Factory pattern and use the Flask-Admin. There is a nice discussion about the underlying problems. I used a very ugly solution, instantiating the Flask-Admin in the init.py file:
from flask_admin.contrib.sqla import ModelView
class UserModelView(ModelView):
create_modal = True
edit_modal = True
can_export = True
def create_app(config_name):
app = Flask(__name__)
app.config.from_object(config[config_name])
db.init_app(app)
# import models here because otherwise it will throw errors
from models import User, Sector, Article
admin.init_app(app)
admin.add_view(UserModelView(User, db.session))
# attach blueprints
from .main import main as main_blueprint
app.register_blueprint(main_blueprint)
from .auth import auth as auth_blueprint
app.register_blueprint(auth_blueprint, url_prefix='/auth')
return app
You don't need a blueprint for that. In views.py add an import for the admin object you defined in your main project:
from projectmodule import admin
from flask.ext.admin import BaseView, expose
class MyView(BaseView):
#expose('/')
def index(self):
return self.render('index.html')
admin.add_view(MyView(name='Hello'))
and in your main projectmodule file use:
from flask import Flask
from flask.ext.admin import Admin
app = Flask(__name__)
admin = Admin(app)
# import the views
import views
app.run()
e.g. you add import views after the line that sets admin = Admin(app).
I have an flask app with one blueprint (and login/logout to admin).
This is the best solution I found to implement flask admin with some custom features.
My structure as follows:
my_app
main
__init__.py
routes.py
static
templates
__init__.py
config.py
models.py
run.py
Customized admin index view from models.py
from flask_admin import AdminIndexView
class MyAdminIndexView(AdminIndexView):
def is_accessible(self):
return current_user.is_authenticated
def inaccessible_callback(self, name, **kwargs):
return redirect(url_for('main.home'))
Main init.py as follows:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_admin import Admin
from flask_admin.menu import MenuLink
from my_app.config import Config
# create extensions
db = SQLAlchemy()
admin = Admin()
def create_app(config_class=Config): # default configutation
app = Flask(__name__)
app.config.from_object(Config)
#initialize extensions
db.init_app(app)
...
# customized admin views
from my_app.models import MyAdminIndexView
admin.init_app(app,index_view=MyAdminIndexView())
admin.add_link(MenuLink(name='Home', url='/'))
admin.add_link(MenuLink(name='Logout', url='/logout'))
#blueprint
from my_app.main.routes import main
app.register_blueprint(main)
return app
I think this is the most elegant solution I came up so far.
In order to keep clean the __init__.py root file:
# app/__init__.py
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from app.config import Config
from flask_admin import Admin
db = SQLAlchemy()
admin = Admin(template_mode="bootstrap3")
def create_app(config_class=Config):
app = Flask(__name__)
app.config.from_object(config_class)
db.init_app(app)
admin.init_app(app)
from app.admin import bp
app.register_blueprint(bp, url_prefix='/admin')
return app
Then in the __init__.py of the Blueprint admin app
# app/admin/__init__.py
from flask import Blueprint
from app import admin, db
from app.models import User
from flask_admin.contrib.sqla import ModelView
bp = Blueprint('admin_app', __name__)
admin.name = 'Admin panel'
admin.add_view(ModelView(User, db.session))
# all the rest stuff

The right place to keep my signals.py file in a Django project

Based on Django's documentation I was reading, it seems like signals.py in the app folder is a good place to start with, but the problem I'm facing is that when I create signals for pre_save and I try to import the class from model it conflicts with the import in my model.
# models.py
from django.contrib.auth.models import User
from django.db import models
from django.utils.translation import gettext as _
from signals import *
class Comm_Queue(CommunicatorAbstract):
queue_statuses = (
('P', _('Pending')),
('S', _('Sent')),
('E', _('Error')),
('R', _('Rejected')),
)
status = models.CharField(max_length=10, db_index=True, default='P')
is_html = models.BooleanField(default=False)
language = models.CharField(max_length=6, choices=settings.LANGUAGES)
sender_email = models.EmailField()
recipient_email = models.EmailField()
subject = models.CharField(max_length=100)
content = models.TextField()
# signals.py
from django.conf import settings
from django.db.models.signals import pre_save
from django.dispatch import receiver
from models import Comm_Queue
#receiver(pre_save, sender=Comm_Queue)
def get_sender_email_from_settings(sender, **kwargs):
obj=kwargs['instance']
if not obj.sender_email:
obj.sender_email='%s' % settings.ADMINS[0][1]
This code will not run because I import Comm_Queue inside signals.py and I also import the signals inside models.py.
Can anyone advice on how I could over come this issue?
Regards
If you're using Django<=1.6 I'd recommend Kamagatos solution: just import your signals at the end of your models module.
For future versions of Django (>=1.7), the recommended way is to import your signals module in your app's config ready() function:
my_app/apps.py
from django.apps import AppConfig
class MyAppConfig(AppConfig):
name = 'my_app'
def ready(self):
import my_app.signals
my_app/__init__.py
default_app_config = 'my_app.apps.MyAppConfig'
Original answer, for Django < 1.7:
You can register the signals by importing signals.py in the app's __init__.py file:
# __init__.py
import signals
This will allow to import models.py from signals.py without circular import errors.
One problem with this approach is that it messes up the coverage results if you're using coverage.py.
Related discussion
Edit: For Django >= 1.7:
Since AppConfig was introduced, the recommended way of importing signals is in its init() function. See Eric Marcos' answer for more details.
To solve your problem you just have to import signals.py after your model definition. That's all.
I also put signals in signals.py file and also have this code snippet that loads all signals:
# import this in url.py file !
import logging
from importlib import import_module
from django.conf import settings
logger = logging.getLogger(__name__)
signal_modules = {}
for app in settings.INSTALLED_APPS:
signals_module = '%s.signals' % app
try:
logger.debug('loading "%s" ..' % signals_module)
signal_modules[app] = import_module(signals_module)
except ImportError as e:
logger.warning(
'failed to import "%s", reason: %s' % (signals_module, str(e)))
This is for project, I'm not sure if it works at app level.
In old Django versions would be fine to put the signals on the __init__.py or maybe in the models.py(although at the end models will be way to large for my taste).
With Django 1.9, it is better I think, to place the signals on a signals.py file and import them with the apps.py, where they are going to be loaded after loading the model.
apps.py:
from django.apps import AppConfig
class PollsConfig(AppConfig):
name = 'polls'
def ready(self):
from . import signals # NOQA
You can also divide your signals on signals.py and handlers.py in another folder within your model named signals as well, but for me that is just over engineering. Take a look at Placing Signals
This only applies if you have your signals in a separate signals.py file
In completely agree with the answer of #EricMarcos but it should be stated that the django docs explicitly advice not to use the default_app_config variable (although it is not wrong). For current versions, correct way would be:
my_app/apps.py
from django.apps import AppConfig
class MyAppConfig(AppConfig):
name = 'my_app'
def ready(self):
import my_app.signals
settings.py
(Make sure you don't just have your app name in installed apps but instead the relative path to your AppConfig)
INSTALLED_APPS = [
'my_app.apps.MyAppConfig',
# ...
]
I'm guessing that you're doing that so your signals are registered, so that they're found somewhere. I just put my signals right in a models.py file normally.
An alternative is to import the callback functions from signals.py and connect them in models.py:
signals.py
def pre_save_callback_function(sender, instance, **kwargs):
# Do stuff here
model.py
# Your imports here
from django.db.models.signals import pre_save
from yourapp.signals import pre_save_callback_function
class YourModel:
# Model stuff here
pre_save.connect(pre_save_callback_function, sender=YourModel)
Ps: Importing YourModel in signals.py will create a recursion; use sender, instead.
Ps2: Saving the instance again in the callback function will create a recursion. You can make a control argument in .save method to control it.

Django: Using 2 different AdminSite instances with different models registered

Apart from the usual admin, I want to create a limited admin for non-staff users. This admin site will have different registered ModelAdmins.
I created a folder /useradmin/ in my project directory and similar to contrib/admin/_init_.py I added an autodiscover() which will register models defined in useradmin.py modules instead of admin.py:
# useradmin/__init__.py
def autodiscover():
# Same as admin.autodiscover() but registers useradmin.py modules
...
for app in settings.INSTALLED_APPS:
mod = import_module(app)
try:
before_import_registry = copy.copy(site._registry)
import_module('%s.useradmin' % app)
except:
site._registry = before_import_registry
if module_has_submodule(mod, 'useradmin'):
raise
I also cretated sites.py under useradmin/ to override AdminSite similar to contrib/admin/sites:
# useradmin/sites.py
class UserAdminSite(AdminSite):
def has_permission(self, request):
# Don't care if the user is staff
return request.user.is_active
def login(self, request):
# Do the login stuff but don't care if the user is staff
if request.user.is_authenticated():
...
else:
...
site = UserAdminSite(name='useradmin')
In the project's URLs:
# urls.py
from django.contrib import admin
import useradmin
admin.autodiscover()
useradmin.autodiscover()
urlpatterns = patterns('',
(r'^admin/', include(admin.site.urls)),
(r'^useradmin/', include(useradmin.site.urls)),
)
And I try to register different models in admin.py and useradmin.py modules under app directories:
# products/useradmin.py
import useradmin
class ProductAdmin(useradmin.ModelAdmin):
pass
useradmin.site.register(Product, ProductAdmin)
But when registering models in useradmin.py like useradmin.site.register(Product, ProductAdmin), I get 'module' object has no attribute 'ModelAdmin' exception. Though when I try this via shell;
import useradmin
from useradmin import ModelAdmin
does not raise any exception.
Any ideas what might be wrong?
Edit:
I tried going the #Luke way and arranged the code as follows as minimal as possible:
(file paths are relative to the project root)
# admin.py
from django.contrib.admin import autodiscover
from django.contrib.admin.sites import AdminSite
user_site = AdminSite(name='useradmin')
# urls.py (does not even have url patterns; just calls autodiscover())
import admin
admin.autodiscover()
# products/admin.py
import admin
from products.models import Product
admin.user_site.register(Product)
As a result I get an AttributeError: 'module' object has no attribute 'user_site' when admin.user_site.register(Product) in products/admin.py is called.
Any ideas?
Solution:
I don't know if there are better ways but, renaming the admin.py in the project root to useradmin.py and updating the imports accordingly resolved the last case, which was a naming and import conflict.
Does useradmin have a ModelAdmin class defined, or do you import it from contrib.admin? I don't see anywhere in the code you supplied where that class gets set up.
That being said, there's a much easier way to do this: just initialize two AdminSites, and then wire them up to the URLs that you want (You can even put them in the same urlconf).