Is there a way to assign a logical value from a comparison to a variable in the current context?
I tried :
{% with hidden=forloop.counter > 4 %}
{% include "path/to/template.html" %}
{% endwith %}
And it didn't work because that causes a syntax error. But perhaps there is just a syntax I don't know?
So far I do something like this :
{% if forloop.counter > 4 %}
{% with hidden=True %}
{% include "path/to/template.html" %}
{% endwith %}
{% else %}
{% include "path/to/template.html" %}
{% endif %}
And it works, But it looks dirty to me.
The include template tag allows you to pass extra context
{% if forloop.counter > 4 %}
{% include "path/to/template.html" with hidden=True %}
{% else %}
{% include "path/to/template.html" %}
{% endif %}
I want to simplify (make more readable) Django template code:
{% comment %}
required variables:
group_id = 'exclude-brands-group'
select_name = 'exclude-brands'
entities = 'excludeBrandsSets'
add_keyword_name = {% trans 'Brand' %}
url_edit_keywords = {{ url_project_filter_exclude_brands_edit_keywords }}
{% endcomment %}
{% with group_id='exclude-keywords-group' select_name='exclude-keywords' %}
{% with entities=excludeKeywordsSets %}
{% trans 'Words' as add_keyword_name %}
{% with url_edit_keywords=url_project_filter_exclude_keywords %}
{% include 'web_site/seo/frontend/seo/filtered_keyword_idea/template/keyword_filter_group.html' %}
{% endwith %}
{% endwith %}
{% endwith %}
But I do not have idea how to reduce number of with tags - since include is only one line command. I have not idea how simplify trans. Do you know some simpler way to pass variables to templates?
The include tag lets you pass additional context to the template. That means you don't need separate with tags (although the downside is you end up with very long lines). There isn't any way to include the trans tag.
{% trans 'Words' as add_keyword_name %}
{% include 'web_site/seo/frontend/seo/filtered_keyword_idea/template/keyword_filter_group.html' with group_id='exclude-keywords-group' select_name='exclude-keywords' entities=excludeKeywordsSets url_edit_keywords=url_project_filter_exclude_keywords %}
Is there a way to check for an empty query set in the Django template? In the example below, I only want the NOTES header to be displayed if there are notes.
If I put an {% empty %} inside the "for" then it does display whatever is inside the empty tag, so it knows it's empty.
I'm hoping for something that does not involve running the query twice.
{% if notes - want something here that works %}
NOTES:
{% for note in notes %}
{{note.text}}
{% endfor %}
{% endif %}
Clarification: the above example "if notes" does not work - it still displays the header even with an empty query set.
Here's a simplified version of the view
sql = "select * from app_notes, app_trips where"
notes = trip_notes.objects.raw(sql,(user_id,))
return render_to_response(template, {"notes":notes},context_instance=RequestContext(request))
Edit: the view select selects from multiple tables.
Have a look at the {% empty %} tag.
Example from the documentation
<ul>
{% for athlete in athlete_list %}
<li>{{ athlete.name }}</li>
{% empty %}
<li>Sorry, no athletes in this list.</li>
{% endfor %}
</ul>
Link: https://docs.djangoproject.com/en/1.8/ref/templates/builtins/#for-empty
If you are interested in a table, or some kind of heading if there are results, add the forloop.first:
{% for athlete in athlete_list %}
{% if forloop.first %}
Athlete Name:
{% endif %}
{{ athlete.name }}
{% empty %}
Sorry, no athletes in this list.
{% endfor %}
Try {% if notes.all %}. It works for me.
In your view check whether notes is empty or not. If it is then you pass None instead:
{"notes": None}
In your template you use {% if notes %} as normal.
It's unfortunate that you're stuck using a raw query set - they're missing a lot of useful behavior.
You could convert the raw query set into a list in the view:
notes_as_list = list(notes)
return render_to_response(template, {"notes":notes_as_list},context_instance=RequestContext(request))
Then check it as a boolean in the template:
{% if notes %}
Header
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
You could also make it happen without conversions using forloop.first:
{% for note in notes %}
{% if forloop.first %}
Header
{% endif %}
{{ note.text }}
{% endfor %}
What about:
{% if notes != None %}
{% if notes %}
NOTES:
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
{% else %}
NO NOTES AT ALL
{% endif %}
Your original solution
{% if notes %}
Header
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
Works now with Django 1.7 and thanks to QuerySet caching, it does not cost and extra query.
Often the right way to do this is to use the {% with ... %} tag. This caches the query so it runs only once and also gives you more flexibility with your markup than using {% empty %}.
{% with notes as my_notes %}
{% if my_notes %}
<ul>
{% for note in my_notes %}
<li>{{ note }}</li>
{% endfor %}
</ul>
{% else %}
<p>Sorry, no notes available</p>
{% endif %}
{% endwith %}
With this particular example I'm not sure how useful it is but if you're querying Many-to-Many field, for instance, it's likely what you want to do.
Use {% empty %} in django templates
{% if list_data %}
{% for data in list_data %}
{{ data.field_1 }}
{% endfor %}
{% else %}
<p>No data found!</p>
{% endif %}
We can write above code with {% empty %}.
{% for data in list_data %}
{{ data.field_1 }}
{% empty %}
<p>No data found!</p>
{% endfor %}
I have a Django template full of nested {% regroup %} tags, and I have the feeling that it is one of the reason why it is so slow. Moreover, it is very complex to maintain like this. Do you have any advise and design patterns to make it faster and more sustainable? I'm open to any suggestion, including moving the logic to models or creating template tags...
Here is a snippet of code, with only the structure, to give you a taste of what it looks like...
{% extends "base.tex" %}
{% block content %}
{% for courseoutline in courseoutline_list %}
...
{% regroup courseoutline.coursemembership_set_by_teaching_unit by teaching_unit as course_list %}
{% for course in course_list %}
{% regroup course.list|dictsort:"course.title" by course.title as course_sublist %}
{% for course in course_sublist %}
{% with course.list|semester:1 as cc %}
...
{% for c in cc %}
...
{% endfor %}
{% endwith %}
{% with course.list|semester:2 as cc %}
{% for c in cc %}
{% endfor %}
{% endwith %}
{% endfor %}
{% endfor %}
{% regroup courseoutline.coursemembership_set_by_semester by semester as semester_list %}
{% for semester in semester_list %}
{% regroup semester.list by teaching_unit as ue_list %}
{% for ue in ue_list %}
{% for course in ue.list|dictsort:"code" %}
{% endfor %}
{% endfor %}
{% endfor %}
{% endfor %}
{% endblock %}
Thanks!
I'm doing something like
{% for part in parts %}
{% include "inc.html" with o=part prefix="part{{ forloop.counter0 }}_" %}
{% endfor %}
where inc.html could be something of such kind:
<p id="{{ prefix }}para">{{ o.text }}</p>
I just discovered the prefix variable isn't interpolated and "part{{ forloop.counter0 }}_" is passed literally.
Any relatively elegant work-around?
I think the best solution would be to register an inclusion_tag, that would handle the part and forloop.counter operations:
#register.inclusion_tag("inc.html")
def inc_tag(part, loop_counter):
prefix = 'part%s_' % (loop_counter,)
context = {
'part': part,
'prefix': prefix,
}
return context
And you would call it like that
{% for part in parts %}
{% inc_tag part=part loop_counter=forloop.counter0 %}
{% endfor %}
Your way is also doable like so, but I wouldn't recommend that
{% for part in parts %}
{% with "part"|add:forloop.counter0|add:"_" as prefx %}
{% include "inc.html" with o=part prefix=prefix %}
{% endwith %}
{% endfor %}