I would like to include the same variables in different templates
vars_catchphrase.twig
{% set catchphrase_size = '' %}
{% if var.tile_catchphrase|length <= 4 %}
{% set catchphrase_size = 'size-lg' %}
{% elseif var.tile_catchphrase|length >= 5 and var.tile_catchphrase|length <= 8 %}
{% set catchphrase_size = 'size-md' %}
{% elseif var.tile_catchphrase|length >= 9 and var.tile_catchphrase|length <= 12 %}
{% set catchphrase_size = 'size-sm' %}
{% elseif var.tile_catchphrase|length >= 13 %}
{% set catchphrase_size = 'size-xs' %}
{% endif %}
I tried to include with this (because the context is sometime different) :
{% include 'vars_catchphrase.twig' with { 'var' : post } %}
When the context is different from post I use another one :
{% include 'vars_catchphrase.twig' with { 'var' : item } %}
example.twig
{% for item in list %}
{% include 'vars_catchphrase.twig' with { 'var' : item } %}
<p class="catchphrase {{ catchphrase_size }}">{{ item.title }}</p>
{% endfor %}
The variable is empty. Can I have some help please ?
Templates you include have their own variable scope, this means variables defined inside this template will not be known out the template. This said, included templates also can't alter the parent's context (by default), this is due to twig passing the context array by value, not by reference.
foo.twig
{% set foo = 'foo' %}
{% include 'bar.twig' %}
{{ foo }}
bar.twig
{% set foo = 'bar' %}
The example above will still output foo
In order to solve your problem, I'd suggest adding a custom filter to twig
<?php
$twig->addFilter(new \Twig\TwigFilter('catchphrase_size', function($value) {
switch(true) {
case strlen($value->tile_catchphrase) >= 13: return 'size-xs';
case strlen($value->tile_catchphrase) >= 9: return 'size-sm';
case strlen($value->tile_catchphrase) >= 5: return 'size-md';
default: return 'size-lg';
}
});
This way you can use the filter where ever,
{% for item in list %}
<p class="catchphrase {{ item|catchphrase_size }}">{{ item.title }}</p>
{% endfor %}
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...
I need to have a nested loop in my Django template, where the outer loop goes through a list of objects, and the inner loop goes through a list of those object id's, and I want to only do something for the id's on the inner list, it never executes however. I think it has something to do with the condition for the if statement, because if I replace it with a true statement it works but it doesn't work as it is now
(I have checked to see that the id's overlap)
{% for outer in outer_obj_list %}
{% for inner_id in inner_id_list %}
{% if outer.id == inner_id %}
// do something
console.log({{inner_id}});
console.log({{outer.id}});
{% endif %}
{% endfor %}
{% endfor %}
Syntax seems correct. I would just verbosely output everything.
Perhaps it should be something like this:
{% for main_obj in main_obj_list %}
main_obj: {{ main_obj }}
{% for obj_id in obj_id_list %}
obj_id: {{ obj_id}}
main_obj: {{ main_obj.id}}
{% if main_obj.id == obj_id %}
// do something
match: {{main_obj.id}} == {{obj_id}} ;
{% endif %}
{% endfor %}
{% endfor %}
Brother I am also face this problem so my clever mind get some clever solution about this problem we can do that with JavaScript easily so we need to run it in JavaScript and then.
{% for outer in outer_obj_list %}
{% for inner_id in inner_id_list %}
if(outer.id == inner_id.id ){
console.log({{inner_id.id}});
console.log({{outer.id}});
//And also if we reserve place in DOM then we can
//change the inner Html of them easily like.
//demo = document.getElementById("demo");
//demo.innerHTML = inner_Id.id or outer.id
}
{% endfor %}
{% endfor %}
It is able to write {{ myval.add:5 }}, {{ myval|add:value }} and even {{ myval|add:-5 }}.
However, I can't find out what I should type to add value * -1 like {{ myval|add:-value }}. This doesn't work, sadly.
You need to use double quotes:
{{ myval|add:"-5" }}
This subtracts five from myval.
The built-in Django template tags/filters aren't all-encompassing, but it's super easy to write your own custom template tags: https://docs.djangoproject.com/en/dev/howto/custom-template-tags/
You could make your own subtract template tag pretty easily:
#register.filter
def subtract(value, arg):
return value - arg
Use django-mathfilters from PyPI: https://pypi.python.org/pypi/django-mathfilters
To install :
$ pip install django-mathfilters
Then add mathfilters in your INSTALLED_APPS.
In template:
{% load mathfilters %}
<ul>
<li>8 + 3 = {{ 8|add:3 }}</li>
<li>13 - 17 = {{ 13|sub:17 }}</li>
{% with answer=42 %}
<li>42 * 0.5 = {{ answer|mul:0.5 }}</li>
{% endwith %}
{% with numerator=12 denominator=3 %}
<li>12 / 3 = {{ numerator|div:denominator }}</li>
{% endwith %}
<li>|-13| = {{ -13|abs }}</li>
</ul>
I recently started working with Django and stumbled upon this one as well: I needed a very simple template loop that stops printing after n times and shows a "more" link to toggle the rest of the items.
With great interest I read the struggle of people trying to understand why this is not being added to the Django default filters (since before 2013). I didn't feel like creating a custom template tag and I kind of found a way to subtract 2 variables using strings and add in combination with with and stringformat
Let's say I have a list of items where I want to print the first 2 and hide the rest, showing how many hidden items are there, eg.
John, Anna and 5 others like this (when given a list of 7 items)
As long as the number of visible items is harcoded in the template (eg. 2), it's possible to add the negative 2 |add:"-2", but I wanted the number of visible items to be a variable as well. The Math-filter library as suggested above doesn't seem up to date (I haven't tested it with Django 2.x).
The trick seems to be to use the add helper to concat the strings "-" with the integer as string, so it can be coerced back to a negative integer in a any consecutive calls to the add helper. This doesn't work however if the value is not a string, so that's where the stringformat helper comes in.
With string value
template posts.html (note how visible is explicitely passed as string - alternative below)
{% for post in posts %}
<h4>{{ post.title }}</h4>
...
{% include 'show_likes.html' with likes=post.likes visible="3" %}
{% endfor %}
template show_likes.html (note the add:0 to make the boolean operator work)
{% with show=visible|default:"2" %}
{% for like in likes %}
{% if forloop.counter <= show|add:0 %}
{% if not forloop.first %},{% endif %}
{{ like.username }}
{% endif %}
{% endfor %}
{% if likes|length > show|add:0 %}
{% with rest="-"|add:show %}
and {{ likes|length|add:rest }} more
{% endwith %}
{% endif %}
like this
{% endwith %}
Alternative with integer
You could just convert your integer to a string in the calling template using |stringformat:"d"
If however the number of visible items you want to show is an integer, you'll have to add a call to stringformat:"d" to have it converted to string
template posts.html
{% for post in posts %}
<h4>{{ post.title }}</h4>
...
{% include 'show_likes.html' with likes=post.likes visible=3 %}
{% endfor %}
template show_likes.html
{% with show=visible|default:2 %}
{% with show_str=show|stringformat:"d" %}
{% for like in likes %}
{% if forloop.counter <= show %}
{% if not forloop.first %},{% endif %}
{{ like.username }}
{% endif %}
{% endfor %}
{% if likes|length > show|add:0 %}
{% with rest="-"|add:show_str %}
and {{ likes|length|add:rest }} more
{% endwith %}
{% endif %}
{% endwith %}
{% endwith %}
Since I'm a very beginner with Django and Python, I'm pretty sure this approach is far worse than actually creating a custom helper! So I'm not suggesting anyone should be using this. This was just my attempt on trying to solve this with the available template helpers and without any custom stuff.
Hope this helps
Lo primero es multiplicar por -1 para convertirlo en una valor negativo y guardarlo en una variable y posterior a usar la suma
The first thing is to multiply by -1 to turn it into a negative value
and save it in a variable and then use the add
{% widthratio val2 1 -1 as result %}
{{result|add:val1}}
After search I found that I can make {% with var=value %} with filters to make the arithmetic operations "with other variables or not"
For example: I have x = 5 and y = 3 and need to add the y's value to x value, all what I need is these steps:
1- Create variable x : {% with x=5 %}
2- Create variable y : {% with y=3 %}
3- In my HTML tags, say <h1>, write that : <h1>{{ x|add:y }}</h1>
4- Close the y's with : {% endwith %}
5- Close the x's with : {% endwith %}
Hope it works with you, it worked with me.
{% with i=3 %}
{% with x=1 %}
<h1>{{i|add:x}}</h1> <!-- result is 4 -->
{% endwith %}
{% endwith %}
How do I write a numeric for loop in a Django template? I mean something like
for i = 1 to n
I've used a simple technique that works nicely for small cases with no special tags and no additional context. Sometimes this comes in handy
{% for i in '0123456789'|make_list %}
{{ forloop.counter }}
{% endfor %}
{% with ''|center:n as range %}
{% for _ in range %}
{{ forloop.counter }}
{% endfor %}
{% endwith %}
Unfortunately, that's not supported in the Django template language. There are a couple of suggestions, but they seem a little complex. I would just put a variable in the context:
...
render_to_response('foo.html', {..., 'range': range(10), ...}, ...)
...
and in the template:
{% for i in range %}
...
{% endfor %}
My take on this issue, i think is the most pythonic. Create a my_filters.py in your apps templatetags directory.
#register.filter(name='times')
def times(number):
return range(number)
Usage in your template:
{% load my_filters %}
{% for i in 15|times %}
<li>Item</li>
{% endfor %}
You can pass a binding of
{'n' : range(n) }
to the template, then do
{% for i in n %}
...
{% endfor %}
Note that you'll get 0-based behavior (0, 1, ... n-1).
(Updated for Python3 compatibility)
Maybe like this?
{% for i in "x"|rjust:"100" %}
...
{% endfor %}
I'm just taking the popular answer a bit further and making it more robust. This lets you specify any start point, so 0 or 1 for example. It also uses python's range feature where the end is one less so it can be used directly with list lengths for example.
#register.filter(name='range')
def filter_range(start, end):
return range(start, end)
Then in your template just include the above template tag file and use the following:
{% load myapp_filters %}
{% for c in 1|range:6 %}
{{ c }}
{% endfor %}
Now you can do 1-6 instead of just 0-6 or hard coding it. Adding a step would require a template tag, this should cover more uses cases so it's a step forward.
You can pass :
{ 'n' : range(n) }
To use template :
{% for i in n %}
...
{% endfor %}
I tried very hard on this question, and I find the best answer here:
(from how to loop 7 times in the django templates)
You can even access the idx!
views.py:
context['loop_times'] = range(1, 8)
html:
{% for i in loop_times %}
<option value={{ i }}>{{ i }}</option>
{% endfor %}
You don't pass n itself, but rather range(n) [the list of integers from 0 to n-1 included], from your view to your template, and in the latter you do {% for i in therange %} (if you absolutely insist on 1-based rather than the normal 0-based index you can use forloop.counter in the loop's body;-).
Just incase anyone else comes across this question… I've created a template tag which lets you create a range(...): http://www.djangosnippets.org/snippets/1926/
Accepts the same arguments as the 'range' builtin and creates a list containing
the result of 'range'.
Syntax:
{% mkrange [start,] stop[, step] as context_name %}
For example:
{% mkrange 5 10 2 as some_range %}
{% for i in some_range %}
{{ i }}: Something I want to repeat\n
{% endfor %}
Produces:
5: Something I want to repeat
7: Something I want to repeat
9: Something I want to repeat
You should use "slice" in template, a example like this:
in views.py
contexts = {
'ALL_STORES': Store.objects.all(),
}
return render_to_response('store_list.html', contexts, RequestContext(request, processors=[custom_processor]))
in store_list.html:
<ul>
{% for store in ALL_STORES|slice:":10" %}
<li class="store_item">{{ store.name }}</li>
{% endfor %}
</ul>
This method supports all the functionality of the standard range([start,] stop[, step]) function
<app>/templatetags/range.py
from django import template
register = template.Library()
#register.filter(name='range')
def _range(_min, args=None):
_max, _step = None, None
if args:
if not isinstance(args, int):
_max, _step = map(int, args.split(','))
else:
_max = args
args = filter(None, (_min, _max, _step))
return range(*args)
Usage:
{% load range %}
<p>stop 5
{% for value in 5|range %}
{{ value }}
{% endfor %}
</p>
<p>start 5 stop 10
{% for value in 5|range:10 %}
{{ value }}
{% endfor %}
</p>
<p>start 5 stop 10 step 2
{% for value in 5|range:"10,2" %}
{{ value }}
{% endfor %}
</p>
Output
<p>stop 5
0 1 2 3 4
</p>
<p>start 5 stop 10
5 6 7 8 9
</p>
<p>start 5 stop 10 step 2
5 7 9
</p>
This essentially requires a range function. A Django feature ticket was raised (https://code.djangoproject.com/ticket/13088) for this but closed as "won't fix" with the following comment.
My impression of this idea is that it is trying to lead to programming in the template. If you have a list of options that need to be rendered, they should be computed in the view, not in the template. If that's as simple as a range of values, then so be it.
They have a good point - Templates are supposed to be very simple representations of the view. You should create the limited required data in the view and pass to the template in the context.
{% for _ in ''|center:13 %}
{{ forloop.counter }}
{% endfor %}
If the number is coming from a model, I found this to be a nice patch to the model:
def iterableQuantity(self):
return range(self.quantity)
You can use:
{% with ''|center: i as range %}
For those who are looking to simple answer, just needing to display an amount of values, let say 3 from 100 posts for example just add {% for post in posts|slice:"3" %} and loop it normally and only 3 posts will be added.
This shows 1 to 20 numbers:
{% for i in "x"|rjust:"20"|make_list %}
{{ forloop.counter }}
{% endfor %}
also this can help you:
(count_all_slider_objects come from views)
{% for i in "x"|rjust:count_all_slider_objects %}
{{ forloop.counter }}
{% endfor %}
or
{% with counter=count_all_slider_objects %}
{% if list_all_slider_objects %}
{% for slide in list_all_slider_objects %}
{{forloop.counter|add:"-1"}}
{% endfor%}
{% endif %}
{% endwith %}
You can pass range(n) instead of n in the context in views.py. This will give you an iterable list.
context['range']= range(n)
Then you can iterate in your template this way:
{% for i in range %}
<!-- your code -->
{% endfor %}
{% for i in range(10) %}
{{ i }}
{% endfor %}