I have 2 models with multiple attributes and I would like to showcase a specific attribute which has multiple instances in another model:
class Carnet(models.Model):
....multiple attributes
class Consultation(models.Model):
....
date_cons = models.DateTimeField(default=datetime.now, blank=True)
There are multiple instances of date_cons. I would like to showcase the latest one added in an html code
The view method I used was this ( probably here is the problem )
def consultation(request, carnet_id):
consultation = Consultation.objects.all()
context = {
'consultation' : consultation
}
return render(request, 'carnets/carnet.html',context)
tried showcasing that attribute in an html code using this syntax
{{consultation.date_cons}}
but it doesn't showcase anything.
How do I showcase this attribute?
You are returning a list of consultation instances. Therefore you must display them in your html accordingly.
Try to use this in your html:
{% for instance in consultation %}
{{ instance.date_cons }}
{% endfor %}
For better readability, I'd use consultations (plural) for the name of the list, and use consultation for the instance in the for loop.
There's a model represents BBS.
I want to make change the value without update database. because I want to preserve the database value. To be precise at display time, I want it to be displayed as '[collabo]' + article.title this is what I am doing at the moment.
below is combine '[collabo]' and all of title with for loop
for article in articles:
article.title = '[collabo]'+article.title
is there any way to change the title value at one line of code? I don't want to change or update database. Or is there a better way.
If you want to do this in a single database query it's one line longer than what you have now!! but it's far more efficient.
from django.db.models import Value
from django.db.models.functions import Concat
Article.objects.annotate(new_title = Concat(V('[collabo]'),'title')))
The annotate method in the queryset is your friend here (with a little help from Concat and Value)
You could also do this at the template level
articles = Article.objects.all()
render('template.html',{'articles': articles})
And then
{% for article in articles %}
[collabo] {{ article.title }}
{% endfor %}
you may work with methods of the model class to give specific modification you want.
models.py
class Article(models.Model):
# some fields ...
def edited_title(self):
return '[collabo] {}'.format(self.title)
then you can exploit it in the templates with {{article.edited_title}}.
i'm looking for a way to extend a django template/view.
my first implementation consists of two models (clients/models.py):
class Client(models.Model):
...
class Address(models.Model):
client = models.ForeignKey(Client)
...
and its fairly simple template (clients/detail.html) :
{{client.name}}
Address: {{client.address.street}}, {{client.address.zipcode}} {{client.address.city}}
as my application grows, a new app was born: 'invoices'.
it is again very simple (invoices/models.py):
class Invoice(models.Model):
client = models.ForeignKey(clients.models.Client)
...
now my clients details-view needs to display invoices, so i create and override clients/detail.html in my 'invoices' app.
good for now.
later on i created a third app 'quotes'.
again my clients details-view needs to display quotes.
if i create clients/detail.html in my 'clients' i will loose the ability to display invoices.
because the 'invoices' and 'quotes' app are indipendent.
my first idea was to create something like a SubView-class
which 'invoices' and 'quotes' can extend and then register their implementation somewhere.
a template should look like this:
{{client.name}}
Address: {{client.address.street}}, {{client.address.zipcode}} {{client.address.city}}
{% for view in views %}
<h1>{{view.title}}</h1>
{{view.get_html}}
{% endfor %}
is this a good way to go and should i use a admin.site-like implementation for registering my sub-views?
In Django one url in urls.py should ideally use one view, just to keep things simple.
I would therefore adopt the approach of putting all the required context in your one view for this screen (I think you already have this via foreign keys in your model). Then, rather than doing what you call "SubView-class" I would go for the Django template include tag.
Example:
{% for invoice in client.invoices %}
{% include "invoice-detail.html" with invoice=invoice %}
{% endfor %}
This renders each invoice's detail for all the invoices of the client. Notice how this is in line with the DRY principle.
I always have issues trying to figure out what the names of variables are available to use in a template. I'm wondering if there is something in the shell I can do to print out all objects available.
Let's say for example you have two models:
class Foo1(models.Model)
id = models.Integer(primary_key=True)
foo2 = models.ForeignKey(Foo2)
class Foo2(models.Model)
id = models.Integer(primary_key=True)
foo3 = models.Integer()
In the shell I do p = Foo1.objects.all() So now p is a QuerySet of all of the values that are contained in both Foo1 and Foo2 (because of the relationship).
Now in my template, in order to pull all of this data out I would normally do something like this:
{% for i in p %}
<p>{{ i.id }}</p>
<p>{{ i.foo2.id }}</p>
<p>{{ i.foo2.foo3 }}</p>
{% endfor %}
Right now I merely guess that the variable syntax to use is i.id, i.foo2.id and i.foo2.foo3, but for more complex QuerySet's this isn't always straightforward. Is there a way to output all of the available variables of a QuerySet and their names?
You should use:
Foo.objects.values_list()
in the view and pass the object as a list rather than as a queryset.
Also check out:
Foo.objects.values()
There's no need to guess. You should be able to find out from the code of the models themselves.
If for some odd reason you haven't got access to the code - and I can't imagine why - you can always use the interactive shell - import your models there, do a query, then do dir(my_obj) to find a list of all the attributes of my_obj.
I'm trying to get my models related using ReferenceProperty, but not have a huge amount of luck. I have 3 levels: Group, Topic, then Pros, and Cons. As in a Group houses many topics, and within each topic could be many Pros and Cons.
I am able to store new Groups nice and fine, but I don't have any idea how to store topics underneath these groups. I want to link from a page with a link "New topic" underneath each group, that takes them to a simple form (1 field for now). Obviously the URL will need to have some sort of reference to the id of the group or something.
Here are my models:
class Groups(db.Model):
group_user = db.UserProperty()
group_name = db.StringProperty(multiline=True)
group_date = db.DateTimeProperty(auto_now_add=True)
class Topics(db.Model):
topic_user = db.UserProperty()
topic_name = db.StringProperty(multiline=True)
topic_date = db.DateTimeProperty(auto_now_add=True)
topic_group = db.ReferenceProperty(Groups, collection_name='topics')
class Pro(db.Model):
pro_user = db.UserProperty()
pro_content = db.StringProperty(multiline=True)
pro_date = db.IntegerProperty(default=0)
pro_topic = db.ReferenceProperty(Topics, collection_name='pros')
class Con(db.Model):
con_user = db.UserProperty()
con_content = db.StringProperty(multiline=True)
con_date = db.IntegerProperty(default=0)
con_topic = db.ReferenceProperty(Topics, collection_name='cons')
And one function for the actual page I want to show the list of Groups, and then underneath their topics:
class Summary(webapp.RequestHandler):
def get(self):
groups_query = Groups.all()
groups = groups_query.fetch(1000)
template_values = {
'groups': groups,
}
path = os.path.join(os.path.dirname(__file__), 'summary.html')
self.response.out.write(template.render(path, template_values))
And finally the html:
<html>
<body>
New Group
<br>
{% for group in groups %}
<font size="24">{{ group.group_name|escape }}</font><br> by <b>{{ group.group_user }}</b> at <b>{{ group.group_date }}</b> {{ group.raw_id }}
<br>
<a href="/newtopic?id={{group.key.id}}" >New topice </a>
<br>
<blockquote>
{{ topics.topics_name }}
</blockquote>
{% endfor %}
</body>
</html>
Something that has side effects, such as altering the store (by creating a new object for example) should NOT be an HTTP GET -- GET should essentially only do "read" operations. This isn't pedantry, it's a key bit of HTTP semantics -- browsers, caches, proxies, etc, are allowed to act on GET as read-only operations (for example by caching results and not passing a request to the server if they can satisfy it from cache).
For modifications, use HTTP verbs such as POST (most popular essentially because all browsers implement it correctly) or for specialized operations PUT (to create new objects) or DELETE (to remove objects). I assume you'll be going to use POST to support a variety of browsers.
To get a POST from a browser, you need either Javascript wizardy or a plain old form with method=post -- I'll assume the latter for simplicity.
If you're using Django 1.0 (which app engine supports now), it has its own mechanisms to make, validate and accept forms based on models. Other frameworks have their own similarly advanced layers.
If you want to avoid "rich" frameworks you'll have to implement by hand templates for your HTML forms, direct them (via some kind of URL dispatching, e.g. in app.yaml) to a handler of yours implementing with a def post(self):, get the data from the request, validate it, form the new object, put it, display some acknowledgment page.
What part or parts of the procedure are unclear to you? Your question's title focuses specifically on reference properties but I'm not sure what problem they are giving you in particular -- from the text of your question you appear to be on the right tack about them.
Edit: the OP has now clarified in a comment that his problem is how to make something like:
"<a href="/newtopic?id={{group.key.id}}" >New topic </a>"
work. There's more than one way to do that. If the newtopic URL is served by a static form, the handler for the post "action" of that form could get back to that id= via the Referer: header (a notorious but unfixable mis-spelling), but that's a bit clunky and fragile. Better is to have the newtopic URI served by a handler whose def get gets the id= from the request and inserts it in the resulting form template -- for example, in a hidden input field. Have that form's template contain (among the other fields):
<INPUT TYPE=hidden NAME=thegroupid VALUE={{ theid }}> </INPUT>
put theid in the context with which you render that template, and it will be in the request that the def post of the action receiving the form finally gets.
Just to answer the question for others as you probably figured this out:
class NewTopic(webapp.RequestHandler):
def get(self):
groupId = self.request.get('group')
# either get the actual group object from the DB and initialize topic with topic_group=object as in 'Nick Johnson's answer, or do as follows
topic = Topic()
topic.name = self.request.get("topicname")
topic.reference = groupId
topic.put()
Thankyou for the reply.
Yeah I am aware of the get vs post. The class I posted was just to actually print all the Groups().
The issue I have is I'm unsure how I use the models to keep data in a sort of hierarchical fashion, with Groups > Topics > Pros/Cons.
Grabbing data is simple enough and I am using:
class NewGroupSubmit(webapp.RequestHandler):
def post(self):
group = Groups()
if users.get_current_user():
group.group_user = users.get_current_user()
group.group_name = self.request.get('groupname')
group.put()
self.redirect('/summary')
I need another function to add a new topic, that stores it within that group. So lets say a group is "Cars" for instance; the topics might be "Ferrari", "Porsche", "BMW", and then pros/cons for each topic. I realise I'm being a little vague, but it's because I'm very new to relational databasing and not quite used to the terminology.
I'm not quite sure what problem you're having. Everything you list looks fine - the ReferenceProperties are set up according to what one would expect from your dscription. The only problem I can see is that in your template, you're referring to a variable "topics", which isn't defined anywhere, and you're not iterating through the topics for a group anywhere. You can do that like this:
<html>
<body>
New Group
<br>
{% for group in groups %}
<font size="24">{{ group.group_name|escape }}</font><br> by <b>{{ group.group_user }}</b> at <b>{{ group.group_date }}</b> {{ group.raw_id }}
<br>
<a href="/newtopic?id={{group.key.id}}" >New topice </a>
<br>
Topics:
<ul>
{% for topic in group.topics %}
<li>{{topic.topic_name}}</li>
{% endfor %}
</ul>
{% endfor %}
</body>
</html>
To create a new topic, just use the constructor, passing in the required arguments:
mytopic = Topic(topic_name="foo", topic_group=somegroup)
Here, somegroup should be either a Group object, or a key for a Group object.