How to reference a foreign key in html django - django

{% for cred in allcreds %}
{% if cred.datasource.name == '...' %}
<h4>{{ cred.datasource }}</h4>
{% endif %}
{% endfor %}
In this case I check the datasource name in the conditional. Then it prints out the datasource. I want to have the datasource in the conditional.

I assume if you print out {{ cred.protocoldatasource }} it will output nothing, because your "relation" protocoldatasource does not exist.
The available foreign-keys that your model ProtocolUserCredentials has are: protocol, data_source, user, protocol_user.
So if you do
{% if cred.data_source.name == 'Demonstration Protocol, ...' %}
or any other of the mentioned relations you can access your related models.
Also note that {% if foo = 'bar' %} is invalid, you'll need to have == in the if-statement.

Related

How to show the first true element after if condition in for loop in django template?

I have a for loop in Django template. After that, I check for coincidences. But in some cases, there are might be 3 coincidences. I need to show only the first coincidence. Now, my code returns the name for 3 times, because, there are 3 coincidences
{% for ip in ips %}
{% if d.name == ip.name %}
<strong>{{ d.name}} </strong>
{% endif %}
{% endfor %}
SOLUTION
It is impossible to break forloop in django template, so I decided to change in views.py through queryset distinction of similar names
ips = Point.objects.defer('point').order_by('name').distinct('name')
I don't recommend doing this in Django Template , but in views itself. But if you can't then you can use {{ forloop|break }}.
Something like this :
{% for ip in ips %}
{% if d.name == ip.name %}
{{ forloop|break }}
<strong>{{ d.name}} </strong>
{% endif %}
{% endfor %}
Check the small snippet example here...

Django Template Tag - Display only one value in nested for loop

I'm working on a Django web app and have the following query:
I have a model called 'AppQoSList' which lists the applications available to all users.
I have then another model called 'BasicAppSDWANProfiles' which has a ManyToMany relationship with 'AppQoSList' .
In short, it means a user can have multiple 'BasicAppSDWANProfiles' associated to his account and multiple AppQoS can be within a particular BasicAppSDWANProfiles:
class AppQoSList(models.Model):
app_qos_name = models.CharField(max_length=50, blank=None, null=True)
app_qos_description = models.CharField(max_length=500)
def __str__(self):
return u'%s' % self.app_qos_name
class BasicAppSDWANProfiles(models.Model):
profile_name = models.CharField(max_length=30)
profile_basic_app_qos = models.ManyToManyField(AppQoSList)
tenant_id = models.ForeignKey(Tenant, default=3)
I'm facing issue in my template when I try to display the list of apps available and the associated BasicAppSDWANProfile:
{% for app in apps %}
{% for profile_app in sdwan_prof %}
{% for specific_app in profile_app.profile_basic_app_qos.all %}
{% ifchanged specific_app.pk %}
{% if app.pk == specific_app.pk %}
<td><h4><span class="label label-primary">{{ profile_app.profile_name }}</span></h4></td>
{% else %}
<td><h4><span class="label label-warning">Not Assigned</span></h4></td>
{% endif %}
{% endifchanged %}
{% endfor %}
{% endfor %}
{% endfor %}
Issue with this code is that 'Not Assigned' is displayed 6 times on each row (which corresponds to the number of Apps found in BasicAppSDWANProfiles associated with this user) whereas I would like to display it only once:
Would you have any solution for this ?
Thanks in advance.
I was able to address this issue.
First I did clean up my view code to remove duplicate 'Not Assigned' values.
I pass to my template context a dictionary with only apps that have a profile assigned such as below:
{'citrix-static': 'DPS-BLACKLIST',
'exchange': 'DPS-BLACKLIST',
'ms-lync-audio': 'DPS-WHITELIST',
'ms-update': 'DPS-GREYLIST',
'rtp': 'DPS-WHITELIST',
'share-point': 'DPS-WHITELIST'}
In my template, I only loop through this dictionary:
{% for k,v in app_prof_assign.items %}
{% if app.app_qos_name == k %}
<td><h4><span class="label label-primary">{{ v }}</span></h4></td>
{% endif %}
{% endfor %}
I then simply check if the app is not in the profile dictionary, outside the loop:
{% if app.app_qos_name not in app_prof_assign %}
<td><h4><span class="label label-warning">Not Assigned</span></h4></td>
{% endif %}
Finally, I can get the table populated as expected:

Compare two table in template

I have two django model, User and Follow.
In the Follow table, I have two attribute a and b which means a following b.
User table is just the django.contrib.auth.User
Let say I am in user A homepage, and A is following B, C and not following D.
I want to list all the username in A's homepage and highlighting those A is following.
In this case B, C should be highlighted and D should not be highlighted.
I was thinking about (pseudocode)
for user in users :
for follow in Following:
if user.username == follow.username:
flag=true
break
if flag:
#print color <p>user.username</p>
else
#print normal..
But I dun think django template allow me to do this.
Is there any other ways to do this?
Here is my code in django template
{% for user in all_user %}
{% for follower in followers %}
{% ifequal user.username follower.follow.username %}
<p class="following">{{user.username}}</p>
{% endifequal %}
{% endfor %}
<p>{{ user.username }}</p>
{% endfor %}
This will duplicate the user that 'A' is following.
Thank you so much
Hm, I would approach this by doing what you have done here, and by passing the variable "flag" to your template, as well as the rest of the objects.
{% if flag == True %}
<do whatever>
{% endif %}
You can also add an attribute to the user in your for loop, then retrieve that in the template.
for user in users :
for follow in Following:
if user.username == follow.username:
user.followed = True
break
Then in your template
{% for user in users %}
{% if user.followed %}
....
{% else %}
....
{% endif %}
{% endfor %}

reduce django db calls

I noticed that my django code calls my database very often with the exact same queries.
I understand that a db hit is made when I actually need the data to display on a page or to evaluate. However, my template code looks like this:
template:
{% if item.listing %}
{{ item.name }} text <strong>{{ item.listing|lowestprice }}</strong> more text
{% else %}
{{ item.name }} even more text
{% endif %}
....
{% for listed_item in item.listing %}
....
{% endfor %}
custom filter:
def lowestprice(value):
try:
val = unicode(value[0].price) + unicode(value[0].symbol)
return val
except:
return "not available"
This code hits my db three times. First on template {% if .. %} second on my custom filter, third on the {% for %} loop.
listing is a method of my models class which is returning a raw SQL queryset with some very expensive joins.
def listing(self):
return Universe.objects.raw("ONE HELL OF A QUERY")
How can I reduce my code to hit the db only once?
Edit: Using with works, but is it possible to avoid db hits on custom filters?
You should use with to do the expensive query once and store it the context.
{% with item.listing as item_listing %}
{% if item_listing %} ... {% endif %} ... etc ...
{% endwith %}

How to limit a collection of objects related on a foreign key in Django Templates?

Given is a model called "comment" with a foreign key relationship to a model called "task".
{% for task in tasks %}
{% for comment in task.comment_set.all %}
{{ comment }}
{% endfor %}
...
What is the best way to limit this to 5 comments like:
Entry.objects.all()[:5]
{% for task in tasks %}
{% for comment in task.comment_set.all|slice:"5" %}
{{ comment }}
{% endfor %}
{% endfor %}
You don't. You should not do "real work" in a template, this breaks the MVC pattern.
Do the real work in the view, and pass the data to the template (using the context dictionary).
def handle_comments(request):
tasks = Task.objects.all()
comments = {}
for task in tasks:
comments[task] = task.comment_set.all()[:5]
return render_to_response('commenting.html', {'comments': comments})
You can then iterate over the comments in your template:
{% for task, task_comments in comments.items %}{{ task }}{% endfor %}