Custom tag for pagination - django

I've been trying to construct my own tag for pagination - pagetag.
But when I render this:
{% if people.has_previous %}
<li><a href={% pagetag people.previous_page_number %}>«</a></li>
{% else %}
<li class="disabled">«</li>
{% endif %}
{% for page in people.paginator.page_range %}
{% if page == people.number %}
<li class="disabled">{{page}}</li>
{% else %}
<li><a href={% pagetag page %}>{{page}}</a></li>
{% endif %}
{% endfor %}
{% if people.has_next %}
<li><a href={% pagetag people.next_page_number %}>»</a></li>
{% else %}
<li class="disabled">»</li>
{% endif %}
I get folowing links on first page:
<li class="disabled">«</li>
<li class="disabled">1</li>
<li><a href=/?page=page>2</a></li>
<li><a href=/?page=page>3</a></li>
<li><a href=/?page=people.next_page_number>»</a></li>
Not the desired ?page=2 and so on.
def pagetag(parser, token):
tokens = token.split_contents()
print tokens
if len(tokens) < 1:
raise TemplateSyntaxError, "pagetag takes at least 1 arguments"
return PageNode(tokens[1].strip())
How to pass the arguments correctly?

Use simple tags. For example:
#register.simple_tag
def pagetag(page):
return '/?page=' + page
Then, in your view, make sure to use {{ }} instead of {% %}:
<li>{{page}}</li>
Note: It's not recommended to use a different tag just for prepending a simple string. Just do it like in the documentation.

Related

blank page in pagination Django 3.1

I implemented the Django pagination to slice the results of the search on my site.
# views.py
def search(request):
# Keywords
if 'keywords' in request.GET:
keywords = request.GET['keywords']
if keywords:
title_list_control_valve = queryset_list.filter(title__icontains=keywords).order_by('title')
description_list_control_valve = queryset_list.filter(description__icontains=keywords).order_by('description').distinct('description')
result_list_control_valves = list(chain(title_list_control_valve,
description_list_control_valve))
result_list_control_valves_2 = list(dict.fromkeys(result_list_control_valves))
paginator = Paginator(result_list_control_valves_2, 1)
page = request.GET.get('page')
paged_queries = paginator.get_page(page)
context = {
'queries': paged_queries,
}
return render(request, 'pages/search.html', context)
else:
return render(request, 'pages/search.html')
else:
return render(request, 'pages/search.html')
the URL of the site when showing search results is :
http://localhost:8000/pages/search/?keywords=something
It works perfectly fine on the first page only. From the second page on, it shows an empty page, and the URL of the site changes to:
http://localhost:8000/pages/search/?page=2
I link to other pages in the HTML as following:
<div class="col-md-12">
{% if queries.has_other_pages %}
<ul class="pagination">
{% if queries.has_previous %}
<li class="page-item">
«
</li>
{% else %}
<li class="page-item disabled">
<a class="page-link">«</a>
</li>
{% endif %}
{% for i in queries.paginator.page_range %}
{% if queries.number == i %}
<li class="page-item active">
<a class="page-link">{{i}}</a>
</li>
{% else %}
<li class="page-item">
{{i}}
</li>
{% endif %}
{% endfor %}
{% if queries.has_next %}
<li class="page-item">
»
</li>
{% else %}
<li class="page-item disabled">
<a class="page-link">»</a>
</li>
{% endif %}
</ul>
{% endif %}
</div>
The ?keywords=something part of the URL goes away.
is it the problem?
how to make the other page's link work too?
Add keywords to your GET params. For ex. href="?page={{queries.previous_page_number}}&keywords={{request.GET.keywords}}"

How to loop through urls in a template

I have a load of URLs I want to declare as constants so I can use them in for and if statements in a template. At the moment I do this manually e.g.:
{% url 'inbox' as inbox %}
{% url 'sent' as sent %}
{% url 'drafts_tasks' as drafts_tasks %}
However this feels kinda clunky and when the urls increase in numbers it is a load of extra code repeated on every template.
Is there a better way I can loop through urls and declare them?
Here's an example of how I want to use them:
{% url 'XXX' as XXX %}
{% for ....
<li class="nav-item {% if request.path == XXX %}active{% endif %}">
<a class="nav-link" href="{{ XXX.url }}">{{ XXX.name }}
</a>
</li>
endfor %}
The easiest option would be to pass the urls as a list.
class URLView(TemplateView):
template_name = 'urls.html'
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['urls'] = get_my_list_of_urls()
return context
As for the repeated code you could make use of the include template tag.
Create a file with the repeating template fragment templates/includes/url_link_list.html:
<li class="nav-item {% if request.path == xxx %}active{% endif %}">
<a class="nav-link" href="{{ xxx.url }}">{{ xxx.name }}</a>
</li>
Then in your urls.html file that was defined in your view you will include that fragment:
<ul>
{% for url in urls %}
{% with url as xxx %}
{% include 'includes/url_link_list.html' %}
{% endwith %}
{% endfor %}
</ul>

django template tag missing 1 required positional argument : value

In my django project I have custom template tag to set correct next link in pagination :
#register.tag(name='url_replace')
def url_replace(request, field, value):
print('this is form tag',request,field,value)
d = request.GET.copy()
d[field] = value
return d.urlencode()
In my template :
{% if is_paginated %}
<ul class="pagination pull-right">
{% if page_obj.has_previous %}
<li>«</li>
{% else %}
<li class="disabled"><span>«</span></li>
{% endif %}
{% for i in paginator.page_range %}
{% if page_obj.number == i %}
<li class="active"><span>{{ i }} <span class="sr-only">(current)</span></span></li>
{% else %}
<li>{{ i }}</li>
{% endif %}
{% endfor %}
{% if page_obj.has_next %}
<li>»</li>
{% else %}
<li class="disabled"><span>»</span></li>
{% endif %}
</ul>
{% endif %}
Looks every thing fine but it is showing me error
Exception Value:
url_replace() missing 1 required positional argument: 'value'
I am unable to figure out the problem as I passed all three arguments !
Change the #register.tag to #register.simple_tag. #register.tag is something bit more complicated
compare
https://docs.djangoproject.com/en/2.0/howto/custom-template-tags/#django.template.Library.simple_tag
with
https://docs.djangoproject.com/en/2.0/howto/custom-template-tags/#registering-the-tag

Django template conditional variable assignment

I want to assign a variable do different values depending on if a variable exists, is this possible? My non working example might make it clearer:
{% if username %}
{% with menu_user=username %}
{% elif recent_users %}
{% with sorted_users=recent_users|dictsortreversed:"timestamp" %}
{% with menu_user=sorted_users.0.username %}
{% endif %}
{% if menu_user %}
<div id="menu">
<ul>
<li>Profile</li>
<li>Products</li>
</ul>
</div>
{% endif %}
{% if recent_users %}
{% endwith %}
{% endif %}
{% endwith %}
Pseudocode of what I try to do:
if username:
menu_user = username
elif recent_users:
menu_user = sorted(recent_users)[0]['username']
if menu_user:
<div id="menu">
<ul>
<li>Profile</li>
<li>Products</li>
</ul>
</div>
update
Then its better to customize a template tag like
#register.inclusion_tag('menu_snippet.html') # or you could use takes_context=True and fetch values from the context
def render_menu(username, recent_users):
if username:
menu_user = username
elif recent_users:
# sorted here could be replaced by min or QuerySet method, it depends
# for example:
# menu_user = min(recent_users, key=lambda u:u.timestamp).username
menu_user = sorted(recent_users)[0]['username']
return {'menu_user':menu_user}
# in template, it looks like
{% render_menu username recent_users %}
Putting the code in the view is much better. Just as your pseudocode, clean and readable.
If you still want to write template, I prefer something like
{% if username %}
<div id="menu">
<ul>
<li>Profile</li>
<li>Products</li>
</ul>
</div>
{% else %}
{% if recent_users %}
{% with sorted_users=recent_users|dictsortreversed:"timestamp" %}
{% with menu_user=sorted_users.0.username %}
<div id="menu">
<ul>
<li>Profile</li>
<li>Products</li>
</ul>
</div>
{% endwith %}{% endwith %}
{% endif %}
{% endif %}
Depends on your actual usage, customized template tag or the include tag are also possibly useful.
Template tag:
#register.assignment_tag
def alias(obj):
"""
Alias Tag
"""
return obj
Template:
{% alias sorted_users.0.username as menu_user %}
Create a template tag that takes username and recent_users as arguments which then outputs the menu. That way you will keep your template clean from that kind of logic.

How can I get a variable passed into an included template in django

I am a Django newbie and am unable to achieve something trivial. Please help me with this.
I am setting a variable pgurl in my views.py
Am able to access the variable {{pgurl}} in my with_tag.html template. This template includes a pagination.html template into itself
In pagination.html I am unable to use the variable {{pgurl}} and nothing is printed
How can I get this variable passed into the included template?
views.py
def with_tag(request, tag, template_name='main/with_tag.html', current_page=1, pgurl=''):
if request.method == 'GET':
query_tag = Tag.objects.get(name=tag)
primes = TaggedItem.objects.get_by_model(Prime, query_tag)
primes = primes.order_by('-date')
request.page = current_page
tcm_pp = TCM_ITEMS_PER_PAGE
pgurl = request.path
else:
return HttpResponseRedirect(request.path)
return direct_to_template(request, template_name, { 'primes' : primes, 'prime_total' : Prime.objects.count(), 'now': datetime.now(), 'page' : current_page, 'tcm_pp' : tcm_pp, 'tag' : tag, 'pgurl' : pgurl })
with_tag.html
{% extends "base.html" %}
{% load comments %}
{% load pagination_tags %}
...
{% include "pagination.html" %}
{% paginate %}
pagination.html
{% if is_paginated %}
{% load i18n %}
<div class="pagination">
{% if page_obj.has_previous %}
‹‹ {% trans "previous" %}
{% else %}
<span class="disabled prev">‹‹ {% trans "previous" %}</span>
{% endif %}
{% for page in pages %}
{% if page %}
{% ifequal page page_obj.number %}
<span class="current page">{{ page }}</span>
{% else %}
{{ page }}
{% endifequal %}
{% else %}
...
{% endif %}
{% endfor %}
{% if page_obj.has_next %}
{% trans "next" %} ››
{% else %}
<span class="disabled next">{% trans "next" %} ››</span>
{% endif %}
</div>
{% endif %}
It will be helpful if you post the output of the rendered page. The context should get passed, might be your template tags instead. Try to do assert and check to see if the variables were passed correctly.