Add dynamic content - django

After a new article is posted (in a form via Ajax) on my Django news site, I want to return a link to the article.
To do so, I'm using a Template object that says:
if form.is_valid():
form.instance.user = request.user
new_article = form.save()
success = Template('<div id="panel_input" class="col-lg-4"> <h2 class="text-center"> Success </h2> <p class="text-center"> Your Article has been posted. You can see and edit details by clicking here. </p></div>')
context = Context({"article_id" : new_article.pk})
return HttpResponse(success.render(context))
The urlsConf for this looks like:
...
url(r'^article/(?P<article_id>\d+)/$', views.article, name='article'),
...
The problem is that I get an error because of {% url "article_manager:article" %}/{{ article_id }}. Apparently, I must pass the article_id inside the previous tag, since the urlsConf requires the id parameter.
But I also get an error when I put the second tag inside the first, like this:
{% url "article_manager:article" {{ article_id }} %}
I'm not sure how to accomplish this task, it doesn't seem to work with the tools I have. Does anyone have any suggestions?

Try {% url "article_manager:article" article_id=article_id %}
Maybe a little more explanation is needed: You were calling the template tag right {% url "namespace:name" %}. Remember that some templatetags can take arguments, in the *args, **kwargs form. The args can be any simple expression understood by the template language, including a context variable (no need to add double-braces). The kwargs follow the same rule, and have the form argument=expression. Thus, you can call some template tags with the form {% tag "exp" 1 request number=5 username=user.name %}

Related

Django / an argument with HttpResponseRedirect is empty in my HTML page

In Views.py
return HttpResponseRedirect('add_scenes?submitted=True?linkToPrevScene=%s'%ScenePrevious)
ScenePrevious is a string containing "water2"
In my URL of add_scenes.html it works :
http://127.0.0.1:8000/scenes3d/add_scenes?submitted=True?linkToPrevScene=water2
But in the file add_scenes.html
{% if submitted %}
your scene was submitted successfully after {{ linkToPrevScene }}
{% else %}
this HTML code doesn't give output for {{ linkToPrevScene }} although {% if submitted %} is evaluated correctly
edit of my post:
This line also doesn't work if I replace the second ? by &
return HttpResponseRedirect('add_scenes?submitted=True&linkToPrevScene=%s'%ScenePrevious)
Sorry I couldn't comment but you need to pass the parameter linkToPrevScene through the view for you to receive it in the template.
**Note:**In Django You can not pass parameters with redirect. Your only bet is to pass them as a part of URL.
#...Rest of your view...
context['linkToPrevScene'] = Water2
redirect(reverse('add_scenes?submitted=True?linkToPrevScene=%s'%ScenePrevious, kwargs={ 'linkToPrevScene': Water2 }))
Use the links below for reference
Django documentaion:
Reverse
Redirect

Check and clear filters with django-filter

I am using django-filter to filter a ListView and would like to display a "Clear all filters" link if any filters are applied.
Due to the generic nature of the filtering system I haven't yet found a straightforward way to achieve this.
The only thing I came up with so far is to return the regular queryset in the get_queryset method of the view if a "clear" flag is present in the request, however this doesn't actually clear the filters - it just returns all the data.
Does anyone have a solution/idea for this?
Update: Solution
After Jerin's comment I decided to solve this problem in 2 separate parts:
has filter:
I check if any of the fields I defined in my filter class are in the request. My solution looks a bit different as I'm using class based views so I abstracted it away in a mixin but if you're using simple views like here, you could just do:
def product_list(request):
f = ProductFilter(request.GET, queryset=Product.objects.all())
has_filter = any(field in request.GET for field in
set(f.get_fields()))
return render(request, 'my_app/template.html', {
'filter': f,
'has_filter': has_filter
})
clear all filters:
A simple redirect to your list view:
{% if has_filter %}
{% trans 'Clear all filters' %}
{% endif %}
Here is the mixup version of the answer (combination of mine and Chris)
You could place a Clear all filters button and that will redirect to your default ListView (/host/end/point/).
But some non-filter parameters (such as pagination or something else) may occur in URL. So the better option is, check for any filter fields in URL and if so, display the filter clearing link
The opted solution is,
def product_list(request):
f = ProductFilter(request.GET, queryset=Product.objects.all())
has_filter = any(field in request.GET for field in set(f.get_fields()))
return render(request, 'my_app/template.html', {
'filter': f,
'has_filter': has_filter
})
and in template,
{% if has_filter %}
{% trans 'Clear all filters' %}
{% endif %}
Just make a button and point to the base search field.
<a class="btn btn-warning" href="{% url 'App:FilterView' %}">Reset</a>
If your FilterSet instance is available on the template you can check for filter.is_bound like this:
{% if filter.is_bound %}
Clear filters
{% endif %}
If you are using the FilterMixin or the FilterView, your FilterSet instance will be available as filter to the template as above.
I like this simple solution, however when I attempt to use it the current filter parameters are some how getting appended to the url even though it's the base url in the anchor.
So hovering over the button my link (determined using {% url 'app:view' %} shows
localhost/app/view correctly
However when clicking the button the url in browser has the parameters appended
localhost/app/view/?filter1=val1&filter2=val2 etc.
Is django caching something? Is browser (Chrome) caching? Can I force something in the anchor to not use them?
Answered my own, but for anyone else passing by:
I had the anchor on a button within a the filter form, although it was not a submit button moving it outside the form gave the desired result.

loop in Django template: how to control the loop iterator?

I'm using Django to show a list of posts. Each post has a 'is_public' field, so if one post's 'is_public' equals to False, it should not be shown to the user. Also, I want to show a fixed number of posts in one page, but this number can be changing depending on views.
I decided to crop the queryset in template as a few views are using the same template, generating it in the view means a lot of repeated codes.
If written in python, it should look like this:
i=number_of_posts_to_show_in_one_page
while i:
if qs[i].is_public == True:
#show qs[i] to the page
i--
As the django template does not support while loop and for loop seems hard to control, is there a way of achieving this? Or should I do it in another way?(One idea is to crop the qs before looping)Thanks!
Update:
I've written this template tag to pre-process the queryset:
#register.simple_tag(takes_context=True)
def pre_process_list(context,list,numbers):
#if not user.has_perm('admin'):
context['result_list']=list.filter(is_public=True, is_removed=False)[0:numbers]
#else:
#context['result_list']=list[0:numbers]
return ''
Before using for loop in the template, I'll pass the queryset to this templage tag, and use a simple for loop to show its result.
If in the future I want to show non-public posts to admins(which is not decided yet), I can write in some logic like the commented ones, and have them styled differently in the template.
{% for post in posts %}
{% if post.is_public %}
{{ post }}
{% endif %}
{% endfor %}
Though this would be a perfect use case for a manager.
You could write a simple manager that filters public posts.
class PublicPostManager(models.Manager):
def get_query_set(self):
return super(PublicPostManager, self).get_query_set().filter(is_public=True)
Then you would add it to your Post Class:
class Post(models.Model):
...
public = PublicPostManager()
Then you could pass post.public.all() as public_posts to your template and simplify your loop:
{% for post in public_posts %}
{{ post }}
{% endfor %}
#arie has a good approach with the manager, but you can easily do the same without writing a manager:
# View
posts = Post.objects.filter(is_public=True) # or use the manager
# Now, you can either limit the number of posts you send
# posts = posts[:5] (only show five in the view)
return render_to_response('foo.html',{'posts':posts})
# Template
# Or you can do the limits in your template itself:
{% for post in posts|slice:":5" %}
{{ post }}
{% endfor %}
See the slice filter on more information.
However, since this is a common operation, with django 1.3 you can use class based views to automate most of this.

if..else custom template tag

I'm implementing a custom permissions application in my Django project, and I'm lost as to how to implement a custom template tag that checks a logged in user's permissions for a specific object instance and shows a piece of HTML based on the outcome of the check.
What I have now is (pseudocode):
{% check_permission request.user "can_edit" on article %}
<form>...</form>
{% endcheck %}
('check_permission' is my custom template tag).
The templatetag takes in the user, the permission and the object instance and returns the enclosed HTML (the form). This currently works fine.
What I would like to do however, is something like:
{% if check_permission request.user "can_edit" on article %}
<form>...</form>
{% else %}
{{ article }}
{% endif %}
I've read about the assignment tag, but my fear is that I would pollute the context variable space with this (meaning I might overwrite previous permission context variables). In other words, as the context variables are being defined on different levels (the view, middleware in my case, and now this assignment template tag), I'm worried about maintainability.
You can use template filters inside if statements. So you could rewrite your tag as a filter:
{% if request.user|check_can_edit:article %}
Note that it's tricky to pass multiple arguments of different types to a filter, so you'll probably want to use one filter per permission, above I've used check_can_edit.
You can definitely do that if you're willing to write some more lines of python code to improve your template readability! :)
You need to parse the tag content yourself, even the parameters it takes and then resolve them, if you want to use variables on them.
The tag implemented below can be used like this:
{% load mytag %}
{% mytag True %}Hi{% else %}Hey{% endmytag %} Bro
Or with a variable:
{% mytag myobject.myflag %}Hi{% else %}Hey{% endmytag %} Bro
So, here's the way I did it:
from django.template import Library, Node, TemplateSyntaxError
register = Library()
#register.tag
def mytag(parser, token):
# Separating the tag name from the "test" parameter.
try:
tag, test = token.contents.split()
except (ValueError, TypeError):
raise TemplateSyntaxError(
"'%s' tag takes two parameters" % tag)
default_states = ['mytag', 'else']
end_tag = 'endmytag'
# Place to store the states and their values
states = {}
# Let's iterate over our context and find our tokens
while token.contents != end_tag:
current = token.contents
states[current.split()[0]] = parser.parse(default_states + [end_tag])
token = parser.next_token()
test_var = parser.compile_filter(test)
return MyNode(states, test_var)
class MyNode(Node):
def __init__(self, states, test_var):
self.states = states
self.test_var = test_var
def render(self, context):
# Resolving variables passed by the user
test_var = self.test_name.resolve(context, True)
# Rendering the right state. You can add a function call, use a
# library or whatever here to decide if the value is true or false.
is_true = bool(test_var)
return self.states[is_true and 'myvar' or 'else'].render(context)
And that's it. HTH.
In Django 2 the assignment tag was replaced by simple_tag() but you could store the custom tag result as a template variable:
# I'm assuming that check_permission receives user and article,
# checks if the user can edit the article and return True or False
{% check_permission user article as permission_cleared %}
{% if permission_cleared %}
<form>...</form>
{% else %}
{{ article }}
{% endif %}
Check the current doc about custom template tags: https://docs.djangoproject.com/en/2.1/howto/custom-template-tags/#simple-tags
inside my_tags.py
from django import template
register = template.Library()
#register.simple_tag(takes_context=True)
def make_my_variable_true(context):
context['my_variable'] = True
return '' # without this you'll get a "None" in your html
inside my_template.html
{% load my_tags %}
{% make_my_variable_true %}
{% if my_variable %}foo{% endif %}
In this case best solution is to use custom filter. If you don't want write long code for custom tag. Also if you don't want to copy/paste others code.
Here is an example
Inside templatetag
register = template.Library()
def exam_available(user, skill):
skill = get_object_or_404(Skill, id=skill)
return skill.exam_available(user)
register.filter('exam_available', exam_available)
Inside template
{{ request.user|exam:skill.id }}
or
{% if request.user|exam:skill.id %}
Since one of the main common of it is to use request.user or any specific object(id) inside model's custom method, so filtering that individual object or user is the easiest way to make it done. :)

Threadedcomments - csrf token and user_name

I am using django-threadedcomments. Everything works fine except 2 things: csrf token and user template tag.
Problem is, when user submits a comment, there is no csrf token for the form, so the form could not be validated server-side. Tried adding csrf token to the dictionaries that threaded-comments passes internal with no result; kept receiving errors (most of them telling that this-method takes only 2 arguments with 3 given). Tried to fix those methods to accept 3 arguments and just pass third one further; no success.
Did someone stumble upon the same problem in past and solved it? because this is not an acceptable solution for me:
MIDDLEWARE_CLASSES = (
#'django.middleware.csrf.CsrfViewMiddleware',
)
Second one - there is a HTML helper to get the user_id for the user who posted a comment. Is there an out of the box html helper to get the name of the user by id or would i have to write it myself?
http://code.google.com/p/django-threadedcomments/
Here is the code for the project, I cant really tell exactly which chunks of it should be posted here so I just give link to the entire project.
I am really stuck in here and any help would be welcomed.
Thanks in advance.
Tried adding csrf token to the
dictionaries that threaded-comments
passes internal with no result;
csrf_token is a template tag -- it shouldn't be passed as an argument somewhere.
I took a look at threadedcomments and it's based on contrib.comments with no html rendering, so it's up to you to insert the csrf_token in your template.
What does your TEMPLATE code look like that is displaying your form code?
If you have CsrfViewMiddleware enabled and you are using RequestContext in your view, you simply need to add {% csrf_token %} inside of your <form></form> tags.
As for getting the user name:
ThreadedComment is a subclasses of Comment which has a name property, or you could just access the User directly...
{% for comment in comments %
{{ comment.user.first_name }}
{{ comment.name }}
{% endfor %}
You should use {% csrf_token %} tag or #csrf_protect in a views
You can put your form in its own template and {% include %} it into your page template. As of Django 1.3, {% include %} can pass context variables to the included template. Here's what I'm using with django.contrib.comments instead of a templatetag:
...
{% include "comments/comment-form.html" with content_object=article user=request.user %}
...
{%csrf_token %} works in this included template because it's using your main view context.