TEMPLATE:
<ul id="bugs-list">
{% for group in groups %}
<h2>{{ group.name }}</h2> <span></span>
{% for data in group.grab_bugs %}
<li>{{data.name }}</li>
{% endfor %}
{% endfor %}
</ul>
models.py:
class BrowserGroups( models.Model ):
name = models.CharField( max_length=100 )
slug = models.SlugField(unique=True)
browsers = models.ManyToManyField( 'Browser' )
def grab_bugs(self):
bugs = Bug.objects.filter(browser__browsergroups=self,really_bug=True).distinct()
return bugs
def __unicode__(self):
return self.name
class Meta:
verbose_name_plural = 'Browser Groups'
I'm trying to render the number of bugs (data) near the <h2>. What would be an efficient way of including the count of data near the h2? Should I define a separate function in my model class to return the total # of bugs? Or is there a more efficient way?
{% with group.grab_bugs as distinct_bugs %}
<h2>{{ group.name }}</h2> (Count: {{ distinct_bugs.count }})
{% for data in distinct_bugs %}
<li>{{data.name }}</li>
{% endfor %}
{% endwith %}
Explanation: the grab_bugs method of the Group class returns a querset of Bug instances. To get a count of the bugs invoke the count() method on the queryset.
This will cost you two queries (not counting the ones inside the loop). One to get the count and then next to retrieve a list of bugs.
Related
I have the following template:
{% extends "artdb/base.html" %}
{% block content1 %}
<h4>Persons:</h4>
<ul>
{% for p in ans %}
<h5>First name: {{p.firstName}}</h5>
<h5>Last name: {{p.lastName}}</h5>
<h5>Phone: {{p.phoneNumber}}</h5>
<h5>Adress: {{p.streetAdress}}</h5>
<h5>Zip Code: {{p.zipcode}}</h5>
<h5>City: {{p.city}}</h5>
<hr>
{% endfor %}
</ul>
{% endblock content1 %}
{% block content2 %}
<h4>Roles:</h4>
<ul>
{% for p in ans %}
<h5>Role:{{p.persons.role}}</h5>
<hr>
{% endfor %}
</ul>
{% endblock content2 %}
and the model:
class Person(models.Model):
mail=models.EmailField()
firstName=models.CharField(max_length=200)
lastName=models.CharField(max_length=200)
phoneNumber=PhoneNumberField()
streetAdress=models.CharField(max_length=200)
zipcode=models.CharField(max_length=200)
city=models.CharField(max_length=200,default="Göteborg")
country=models.CharField(max_length=200,default="Sweden")
def __str__(self):
return "%s %s" % (self.firstName,self.lastName)
class Meta:
ordering = ('firstName','lastName')
class Role(models.Model):
role=models.CharField(max_length=200)
person=models.ManyToManyField(Person)
def __str__(self):
return self.role
class Meta:
ordering = ('role',)
But when I run the above code the only output that I get is from the block content1, i.e I cannot access the role content. I thought that role.persons.role would do it but apperantley not. There is a many-to-many relationship between perssons and roles.
Any ideas?
This should work
{% block content2 %}
<h4>Roles:</h4>
<ul>
{% for p in ans %}
{% for role in p.role_set.all %}
<h5>Role:{{ role }}</h5>
<hr>
{% endfor %}
{% endfor %}
</ul>
{% endblock content2 %}
We have to create a second for loop, since a many to many relationship will always return a list. Not a single instance. So essentially it's just like accessing a 2d array.
In Django you only have to define a n:n relationship on one end. Django will then automatically add it to the other model as well. It does this by taking the related model name and suffixing _set. So if we want to reference all of the roles attached to a person, it would be person.role_set. The other way around it would be role.person like you defined in the model.
I have two models with one having a foreign key to the other as such:
Models:
class WhoAmI(models.Model):
name = models.CharField(max_length=200)
company = models.CharField(max_length=200)
def __str__(self):
return self.name
class SolarClient(models.Model):
name = models.CharField(max_length=200)
client_owner = models.ForeignKey(WhoAmI, on_delete=models.CASCADE, related_name='solarclients')
addr = models.CharField(max_length=200)
city = models.CharField(max_length=200)
state = models.CharField(max_length=200)
email = models.EmailField()
I am trying to simply display an html table showing each client a salesperson has, with the salesperson listed first with a table of clients below their name.
The only way I could figure out how to do this was to create a dictionary using the code shown below.
class Homeowners(DetailView):
def get(self, request, **kwargs):
salespersons = WhoAmI.objects.all()
homeowners = SolarClient.objects.all().order_by("client_owner") #the name 'objects' is the Manager
rangers = {}
for e in salespersons:
k = salespersons.get(id = e.id)
v = k.solarclients.all()
rangers[k] = v
return render(request, 'homeowners.html', {'homeowners': homeowners, 'salespersons': salespersons, 'rangers': rangers })
I then iterate over the dictionary using:
{% for key, values in rangers.items %}
... display salesperson
{% if values %}
{% for v in values %}
.... display clients
{% endfor %}
{% else %}
... display "No Clients"
{% endif %}
{% endfor %}
Is there a more efficient way to do this? It seems silly to put the data into a dictionary to display it, but after many, many hours of trying different methods, this is the only way I could display the data.
thanks for any suggestions.
views.py
class Homeowners(DetailView):
def get(self, request, **kwargs):
salespersons = WhoAmI.objects.all()
return render(request, 'homeowners.html', {'salespersons': salespersons })
html:
{% for sales in salespersons %}
{% for client in sales.solarclients.all %}
------ Print Client
{% empty %}
---- Client not exist
{% endfor %}
{% endfor %}
There is a nice handy template filter called regroup built in Django which does exactly what you're looking for.
# views.py
homeowners = SolarClient.objects.all().order_by("client_owner").select_related('client_owner')
return render(request, 'homeowners.html', {'homeowners': homeowners})
# homeowners.html
{% regroup homeowners by client_owner as home_owners_list %}
<ul>
{% for client_owner in home_owners_list %}
<b>{{ client_owner.grouper }}</b>
<ul>
{% for client in client_owner.list %}
<li>{{ client.name }}</li>
{% endfor %}
</ul>
{% endfor %}
</ul>
The select_related method is just for performance improvement and omitting it wouldn't affect functionality.
I am trying to follow this previous question here:
Django: getting the list of related records for a list of objects
but can't seem to get it to work.
I get a list of owners but do not get a list of pet names. The html code doesn't seem to execute the 2nd FOR loop. Any ideas?
models.py
class Teacher(models.Model):
teacher = models.CharField(max_length=300, verbose_name="teacher")
def __unicode__(self):
return self.teacher
class Owner(models.Model):
relevantteacher = models.ForeignKey(Teacher, verbose_name="teacher")
owner = models.CharField(max_length=300, verbose_name="owner")
def __unicode__(self):
return self.owner
class PetName(models.Model):
relevantowner = models.ForeignKey(Owner, verbose_name="owner")
pet_name = models.CharField(max_length=50, verbose_name="pet Name")
def __unicode__(self):
return self.pet_name
views.py
def ownersandteachers(request):
owners = Owner.objects.all()
context = {'owners': owners}
return render(request, 'ownersandpets.html', context)
template
{% for i in owners %}
{{ i.owner }} has pets:<br />
{% for v in owners.petname_set.all %} //this doesn't seem to be executing
- {{ v.pet_name }}<br />
{% endfor %}
{% endfor %}
You are doing
{% for v in owners.petname_set.all %}
where you should be doing
{% for v in i.petname_set.all %}
owners is the queryset, but you need to get the petname_set for the individual object in the queryset which is i in this case.
Also, I would recommend a condition check if i.petname_set exists. If not, do not show the has pets: text.
{% for i in owners %}
{{ i.owner }}
{% if i.petname_set.count %} has pets:<br />
{% for v in i.petname_set.all %} //this doesn't seem to be executing
- {{ v.pet_name }}<br />
{% endfor %}
{% endif %}
{% endfor %}
I have a model called Subtopic. One of my templates runs a forloop on an object, returning a different field for each cell of a table row.
Two of the table cells look up a field which is a ManytoMany foreign key, both to the same foreign model, Resource. I want each to display different results, based on the value of a boolean field within the Resource model.
What you see below is currently working fine, but doesn't attempt to filter by the boolean field.
models.py:
class ICTResourceManager(models.Manager):
def get_query_set(self):
return super(ICTResourceManager, self).get_query_set().filter('is_ict': True)
class NonICTResourceManager(models.Manager):
def get_query_set(self):
return super(NonICTResourceManager, self).get_query_set().filter('is_ict': False)
class Resource(models.Model):
subtopics = models.ManyToManyField(Subtopic)
external_site = models.ForeignKey(ExternalSite)
link_address = models.URLField(max_length=200, unique=True, verify_exists=False)
requires_login = models.BooleanField()
is_ict = models.BooleanField()
flags = models.ManyToManyField(Flag, blank=True)
comment = models.TextField()
def __unicode__(self):
return u'%s %s' % (self.external_site, self.link_address)
objects = models.Manager()
ict_objects = ICTResourceManager()
nonict_objects = NonICTResourceManager()
class Meta:
ordering = ['external_site', 'link_address']
views.py:
def view_ks5topic(request, modulecode, topicshortname):
listofsubtopics = Subtopic.objects.filter(topic__module__code__iexact = modulecode, topic__shortname__iexact = topicshortname)
themodule = Module.objects.get(code__iexact = modulecode)
thetopic = Topic.objects.get(module__code__iexact = modulecode, shortname__iexact = topicshortname)
return render_to_response('topic_page.html', locals())
My template:
{% for whatever in listofsubtopics %}
<tr>
<td>
{{ whatever.objective_html|safe }}
<p>
{% if request.user.is_authenticated %}
{% with 'objective' as column %}
{% include "edit_text.html" %}
{% endwith %}
{% else %}
{% endif %}
</td>
<td>
{% regroup whatever.resource_set.all by external_site.name as resource_list %}
{% for external_site in resource_list %}
<h4>{{ external_site.grouper }}</h4>
<ul>
{% for item in external_site.list %}
<li>{{ item.comment }}</li>
{% endfor %}
</ul>
{% endfor %}
</td>
</tr>
{% endfor %}
As you can see, I've added extra managers to the model to do the filtering for me, but when I replace the appropriate lines in the template, I just get blanks. I have tried: for external_site.ict_objects in resource_list and for item.ict_objects in resource_list and <a href="{{ item.ict_objects.link_address }}">. If this were in the view I could probably do the filter just by .filter('is_ict': True), but with this being inside a forloop I don't know where to do the filtering.
I also tried writing regroup whatever.resource_set.filter('is_ict': True) in the template, but the syntax for regrouping seems to use resource_set.all rather than resource_set.all() (and I don't know why) so the filter text doesn't work here.
Turns out it was possible to do it using a custom template filter. The original efforts to filter within the template weren't working, given that as is well documented the template language is not a fully-fledged python environment. My original question remains open for anyone who knows an alternative method that more directly addresses the question I was originally asking, but here's how I did it:
myapp_extras.py:
from django import template
register = template.Library()
def ict(value, arg):
"filters on whether the is_ict Boolean is true"
return value.filter(is_ict=arg)
register.filter('ict', ict)
My template, note the use of the custom filter in line 2:
<td>
{% regroup whatever.resource_set.all|ict:1 by external_site.name as resource_list %}
{% for external_site in resource_list %}
<h4>{{ external_site.grouper }}</h4>
<ul>
{% for item in external_site.list %}
<li>{{ item.comment }}</li>
{% endfor %}
</ul>
{% endfor %}
</td>
After this I was able to remove the additional custom managers from the model.
One further question, when filtering for the boolean is_ict field, I found that I had to use filter(is_ict=1) and filter(is_ict=0). Is that the only way to refer to a True or False value?
I have two basic models, Story and Category:
class Category(models.Model):
title = models.CharField(max_length=50)
slug = models.SlugField()
...
class Story(models.Model):
headline = models.CharField(max_length=50)
slug = models.SlugField()
categories = models.ManyToManyField(Category)
...
And my view for story detail:
from django.views.generic import date_based, list_detail
from solo.apps.news.models import Story
def story_detail(request, slug, year, month, day):
"""
Displays story detail. If user is superuser, view will display
unpublished story detail for previewing purposes.
"""
stories = None
if request.user.is_superuser:
stories = Story.objects.all()
else:
stories = Story.objects.live()
return date_based.object_detail(
request,
year=year,
month=month,
day=day,
date_field='pub_date',
slug=slug,
queryset=stories,
template_object_name = 'story',
)
On the view for a given story object -- I'm using a generic detail view -- I'd like to display a list of stories related to the current story via the categories applied to the current story.
Here's how I'm doing this currently in the story detail template:
{% for category in story.category.all %}
<ul id="related_stories">
{% for story in category.story_set.all|slice:"5" %}
<li>{{ story.headline }}</li>
{% endfor %}
</ul>
{% endfor %}
This provides me what I need except I'd like to avoid displaying the linked headline for the story I'm viewing currently.
I believe this is done via the "exclude" filter, but I'm not sure if this belongs on the Category or Story model as a method, or how to construct it.
Any help would be appreciated!
Do this:
class Story(models.Model):
...
#property
def related_story_set(self):
category_id_list = self.category.values_list("id", flat=True)
return Story.objects.filter(category__id__in=category_id_list).exclude(id=self.id)
Then you can do this in the template:
<ul id="related_stories">
{% for related_story in story.related_story_set.all|slice:"5" %}
<li>{{ related_story.headline }}</li>
{% endfor %}
</ul>
You could just check in the template if the currently iterated story is the original story:
{% for category in story.category.all %}
<ul id="related_stories">
{% for substory in category.story_set.all|slice:"5" %}
{% if substory != story %}
<li>{{ story.headline }}</li>
{% endif %}
{% endfor %}
</ul>
{% endfor %}
You asked to put it in a model method:
class Story(models.Model):
...
def get_categories_with_stories(self):
categories = self.category.all()
for category in categories:
category.stories = category.story_set.exclude(id=self.id)[:5]
return categories
This doesn't solve your expensive query issue, but that wasn't a part of the question.
{% for category in story.get_categories_with_stories %}
<ul id="related_stories">
{% for substory in category.stories %}
<li>{{ story.headline }}</li>
{% endfor %}
</ul>
{% endfor %}