Comparing dates using a comparator inside Django template - python

I am trying to compare the end date of an event with today's date to see if the event has ended. If the event has ended, the website user would not have a button to enrol and if the event has not started or is ongoing, the user would have a button to enrol in html.
I have tried this in my html template:
{% if event.end_date|date:"jS F Y H:i" <= today|date:"jS F Y H:i" %}
{% include 'event/includes/enroll.html' %}
But the button shows whether or not the event has ended already.
I wanted to add a method in my django model like this:
#property
def is_today(self):
return self.datefinish == datetime.today().date()
But I am not sure how to import the method and use it in html template then.
I wanted to try to add a variable in my view like this: (Django - Checking datetime in an 'if' statement)
is_today = model.end_date >= datetime.today()
return render_to_response('template.html', {'is_today': is_today})
But a colleague has written a Class-based view to render the template and not sure how to add the variable to render using the class-based view. I also got an error:
TypeError: '>=' not supported between instances of 'DeferredAttribute' and 'datetime.datetime'
If anyone can advice on how to best achieve what I need, I would be grateful :D

Hello why dont you use a custom_filter, that will return True or False in your template ? (https://docs.djangoproject.com/fr/3.1/howto/custom-template-tags/):
import datetime
from django import template
from django.conf import settings
register = template.Library()
#register.filter
def event_ended(date_event):
return date_event >= datetime.date.today()
{% load poll_extras %}
{% if event.end_date | event_ended %}
{% include 'event/includes/enroll.html' %}
The link from the documentation told you where to put the custom template

Related

Single View with Dynamic template

I've got modules that if enabled/disabled would require a different arrangement of tables and iframes on the frontend webpage. In order to do this I set up a function to check which modules are enabled/disabled and assigned a number to each 'set' and will be created separate templates for each "set1.html", "set2.html", "set3.html", etc...
I'd like to utilize one single view where I can pass the set number from from function I created but I can't seem to figure out how.
def homeset(request):
return render(request, 'app/set1.html', {})
Looking to figure out some way to make the "1" the return of the function I created to determine which set# to load as template and would prefer to not have to create a view for every single template needed.
Just taking a stab at this, do you have a problem with setting the template name before rendering?
def homeset(request):
# define 'my_set'
# define num
...
my_template_name = None
if num in my_set:
my_template_name = 'app/set{}.html'.format(num)
return render(request, my_template_name)
Looks like Scott Skiles answered your question, but an alternative way is to use a single base template and the "include" templatetag.
You can pass the set number to the template and use the "if" templatetag" to include the content from appropriate template(s) for each set number.
{% if set_num == 1 %}
{% include "foo/bar.html" %}
{% elif set_num == 2 %}
{% include "foo/two.html" %}
{% endif %}

I want to use the if statement based on the existence of a web page

So basically i have a complicated scenario. I am current using Django to build a website and i have current made two apps. Both apps have almost identical fields. The field I would want to focus on though is the Information field(which they both have and which i have auto generated with the help of the Wikipedia model)
So the case here is that I want to create an if and else statement in the html in such a way that if the page i am hyperlinking to exists it would go to the link dealing with DetailView but if it doesnt exist I would redirected to the Create View
I should also note that the two apps have their names linked with the help of the foreign key but when i try to open information links using the same name , they gave me different pks
I dont feel like i explained my problem well enough but I hope someone can understand what i mean
UPDATE
ok I create the get function using
def get(self, request, *args, **kwargs):
try:
self.object = self.get_object()
except Http404:
return redirect('/create/')
context = self.get_context_data(object=self.object)
return self.render_to_response(context)
but i dont know how to use the CreateView fuction i created instead of the link i put
This is the Detail View Html
{%extends "home.html"%}
{%block head_title%} {{block.super}}{%endblock head_title%}
{% block content%}
<!-- verify authentication -->
{% if request.user.is_authenticated%}
<h3>{{object.title}}</h3><br/>
{% endif %}
<ul type="disc">
<div class="container">
<li><b>Artist: </b>{{object.Summary}}</li>
<li><b>Genre: </b>{{object.Genre}}</li>
<li><b>Bio: </b><br>{{object.Bio}}</li>
EDIT
</div>
</ul>
{%endif%}
{% endblock %}
This is my model
from django.db import models
from django.conf import settings
from Blog.models import MainPage
from django.urls.base import reverse
from Blog.Retrieve import retriever
from django.db.models.signals import pre_save,post_save
import InfoPedia
class InfoPedia(models.Model):
user =models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)
Name =models.ForeignKey(MainPage,on_delete=models.CASCADE)
Location =models.CharField(max_length= 50,null=True,blank=True)
Information =models.TextField(null=True,blank=True)
TrackListing=models.TextField(null=True,blank=True)
Published=models.BooleanField(default=True)
Timestamp=models.DateTimeField(auto_now=True)
Updated=models.DateTimeField(auto_now=True)
def get_absolute_url(self):
# return f"/Blog/{self.slug}"
return reverse('InfoPedia:DetailView', kwargs={"pk":self.pk})
class Meta:
ordering=["-Updated","-Timestamp"] #orranges in order of updated
def get_tracklist(self):
return self.TrackListing.split(",")
def Information_create_pre_save( instance, sender, **kwargs):
instance.Information=retriever(instance.Name)
def rl_post_save_reciever(sender, instance,created,*args,**kwargs):
print("saved")
print(instance.Timestamp)
pre_save.connect(Information_create_pre_save, sender=InfoPedia)
post_save.connect(rl_post_save_reciever, sender=InfoPedia)
An alternative - rather than checking the if/else in the HTML, just make all the links to the DetailView URL.
Then, in the get() handler for the DetailView, you perform a queryset lookup for the object. If no object is found, then instead of displaying the DetailView HTML, return to the user a 302 redirect (i.e. a temporary redirect) to the CreateView for that object. So all your if/else logic is in the view function or class, instead of HTML.

How to display current year in Flask template?

I am looking to find out how to output the current year in a Flask template. I know in Django you can use {% now "Y" %}., but is there a Flask equivalent? I have been unable to find anything during my research thus far.
Use a template context processor to pass the current date to every template, then render its year attribute.
from datetime import datetime
#app.context_processor
def inject_now():
return {'now': datetime.utcnow()}
{{ now.year }}
Or pass the object with render if you don't need it in most templates.
return render_template('show.html', now=datetime.utcnow())
For moment there is Flask Moment. It is powerful like Moment, and easy to use in Flask. To display the year in the user's local time from your Jinja template:
<p>The current year is: {{ moment().format('YYYY') }}.</p>
If using Jinja2 is too cumbersome and you are using Jinja2 in a context of a browser that you can simply use Javascript.
Using Simple Javascript
<span id="year"></span>
const year = document.querySelector('#year');
if (year) {
year.innerHTML = new Date().getFullYear().toString();
}
JavaScript library like moment.js
<script>
document.write(moment("2012-12-31T23:55:13 Z").format('LLLL'));
</script>

In a jinja2 template, how do i check if an element in a mongo database is one of three possible strings?

My template has if/else functionality to handle displaying buttons on a page, I've managed to add an elif statement that displays the buttons only if an element in a mongo database is not one of three values. I'm trying to clean this up as the elif appears four times across two jinja2 templates. My code which works now looks like this:
{% elif (
('string1' not in database.category) and ('string2' not in database.category) and
('string3' not in database.category)) %}
I've tried declaring a tuple and doing a:
{% set hidebuttons = ['string1' , 'string2' , 'string3'] %} //sets tuple
{% elif not database.category in hidebuttons %} // checks if value not in tuple
and plenty of other methods to make this work but every time I reload the web page i keep seeing the buttons when i shouldn't be. Any advice is greatly appreciated.
I believe this should be in your view, not your template. If you need to do the query in more then one place, you can create a utility function that gets the results you need, then in your views, you can call the function and pass the data as context to your templates
if you're using a view_config decorator to render template, it could be something like:
#view_config(renderer='templates/foo.pt')
def my_view(request):
show_buttons = logic_to_determine_should_buttons_be_shown()
return {'show_buttons': show_buttons }
# your template
{% if show_buttons %}
show buttons
{% endif %}

How to pass information using an HTTP redirect (in Django)

I have a view that accepts a form submission and updates a model.
After updating the model, I want to redirect to another page, and I want a message such as "Field X successfully updated" to appear on this page.
How can I "pass" this message to the other page? HttpResponseRedirect only accepts a URL. I've seen this done before on other sites. How is this accomplished?
This is a built-in feature of Django, called "messages"
See http://docs.djangoproject.com/en/dev/topics/auth/#messages
From the documentation:
A message is associated with a User.
There's no concept of expiration or
timestamps.
Messages are used by the Django admin
after successful actions. For example,
"The poll Foo was created
successfully." is a message.
You can use django-flashcookie app
http://bitbucket.org/offline/django-flashcookie/wiki/Home
it can send multiple messages and have unlimited types of messages. Lets say you want one message type for warning and one for error messages, you can write
def simple_action(request):
...
request.flash['notice'] = 'Hello World'
return HttpResponseRedirect("/")
or
def simple_action(request):
...
request.flash['error'] = 'something wrong'
return HttpResponseRedirect("/")
or
def simple_action(request):
...
request.flash['notice'] = 'Hello World'
request.flash['error'] = 'something wrong'
return HttpResponseRedirect("/")
or even
def simple_action(request):
...
request.flash['notice'] = 'Hello World'
request.flash['notice'] = 'Hello World 2'
request.flash['error'] = 'something wrong'
request.flash['error'] = 'something wrong 2'
return HttpResponseRedirect("/")
and then in you template show it with
{% for message in flash.notice %}
{{ message }}
{% endfor }}
or
{% for message in flash.notice %}
{{ message }}
{% endfor }}
{% for message in flash.error %}
{{ message }}
{% endfor }}
I liked the idea of using the message framework, but the example in the django documentation doesn't work for me in the context of the question above.
What really annoys me, is the line in the django docs:
If you're using the context processor, your template should be rendered with a RequestContext. Otherwise, ensure messages is available to the template context.
which is incomprehensible to a newbie (like me) and needs to expanded upon, preferably with what those 2 options look like.
I was only able to find solutions that required rendering with RequestContext... which doesn't answer the question above.
I believe I've created a solution for the 2nd option below:
Hopefully this will help someone else.
== urls.py ==
from django.conf.urls.defaults import *
from views import *
urlpatterns = patterns('',
(r'^$', main_page, { 'template_name': 'main_page.html', }, 'main_page'),
(r'^test/$', test ),
== viewtest.py ==
from django.contrib import messages
from django.http import HttpResponseRedirect
from django.core.urlresolvers import reverse
def test(request):
messages.success( request, 'Test successful' )
return HttpResponseRedirect( reverse('main_page') )
== viewmain.py ==
from django.contrib.messages import get_messages
from django.shortcuts import render_to_response
def main_page(request, template_name ):
# create dictionary of items to be passed to the template
c = { messages': get_messages( request ) }
# render page
return render_to_response( template_name, c, )
== main_page.html ==
{% block content %}
{% if messages %}
<div>
{% for message in messages %}
<h2 class="{{message.tag}}">{{ message.message }}</h2>
{% endfor %}
</div>
{% endif %}
{% endblock %}
I have read and checked all answers, and it seems to me that the way to go now is using the messaging framework. Some of the replies are fairly old and have probably been the right way at the time of the posting.
There is a lot of solutions
1 Use Django-trunk version - it support sending messages to Anonymous Users
2 Sessions
def view1(request):
request.session['message'] = 'Hello view2!'
return HttpResponseRedirect('/view2/')
def view2(request):
return HttpResponse(request.session['message'])
3 redirect with param
return HttpResponseRedirect('/view2/?message=Hello+view2')
4 Cookies
Can you just pass the message as a query param oon the URL to which you're redirecting? It's not terribly RESTy, but it ought to work:
return HttpResponseRedirect('/polls/%s/results/?message=Updated" % p.id)
and have that view check for a message param, scrub it for nasties, and display it at the top.
I think this code should work for you
request.user.message_set.create(message="This is some message")
return http.HttpResponseRedirect('/url')
Take a look at Django's messages framework. http://docs.djangoproject.com/en/dev/ref/contrib/messages/#ref-contrib-messages
You could also have the redirect url be the path to an already parameterized view.
urls.py:
(r'^some/path/(?P<field_name>\w+)/$', direct_to_template,
{'template': 'field_updated_message.html',
},
'url-name'
),
views.py:
HttpResponseRedirect( reverse('url-name', args=(myfieldname,)) )
Note that args= needs to take a tuple.
The solution used by Pydev UA is the less intrusive and can be used without modifying almost nothing in your code. When you pass the message, you can update your context in the view that handles the message and in your template you can show it.
I used the same approach, but instead passing a simple text, passed a dict with the information in useful fields for me. Then in the view, updated context as well and then returned the rendered template with the updated context.
Simple, effective and very unobstrusive.
While all suggestions so far work, I would suggest going with Ry4an's (pass it in the request URL) - just change the actual text to a coded text within a predefined set of text messages.
Two advantages here:
Less chance of something hacking through your scrubbing of bad content
You can localize your messages later if needed.
The other cookie related methods.. well, they don't work if the browser doesn't support cookies, and are slightly more expensive.. But only slightly. They're indeed cleaner to the eye.

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