Django Templatetag loading - django

Quick question guys,
Just say I have the code below:
{% for i in c.targetItems %}
<tr> {% include "transfers/matching/_process_match_format.html" %} </tr>
{% endfor %}
In the "_process_match_format.html" I am using a custom template tag. I have to load it in this inclusion file rather then it's parent page otherwise it doesn't seem to be available. Does django only load the custom tag once or does it load it on every pass of the loop?
Additionally, is there way to load the tag in the parent page and make it available for any includes?

According to Django docs: "This means that there is no shared state between included templates -- each include is a completely independent rendering process.". Seems it will load tags each time include is called.
There is a way to load tags for all templates, you need to add them to built-in template tags: Load a Django template tag library for all views by default

Related

Django template nested include passing variables

I use django template index.html to render the frontpage. It includes another template to create a link icon. This template url_icon.html includes another template icon.html. When passing the arguments down the way, I face with an error. How to fix it?
index.html
.
.
.
{% include "url_icon.html" with name="return" url="/" %}
.
.
.
url_icon.html
{% include "icon.html" with icon={{ name }} %}
icon.html
<img src="/static/images/{{ name }}.png" />
Causing an error:
Could not parse the remainder: '{{' from '{{'
it looks like there are a few things you can do to improve/fix this. Addressing #1 and #2 should fix your issue. I've also added suggestions for best practices that would probably require refactoring (#3, #4).
It looks like you need to remove the curly-braces from name inside the {% include %} tag. Context variables can be used inside tags without extra syntax.
url_icon.html:
{% include "icon.html" with icon=name %}
icon.html will have access to name since you're not using the only keyword when updating its context, so your code might appear to work at first ({% include %} documentation). However, it looks like your intention is to refer to it as icon.
Use the variable icon in instead of name
icon.html:
<img src="/static/images/{{ icon }}.png" />
Optional suggestion: Use Django's staticfiles system
Try using the {% static %} tag for your icon. This will help make deployment easier, especially if you use a separate CDN from your webserver. There's lots of literature on how to set up staticfiles for Django projects in production, it's a large topic, but you'll be able to approach it more easily if you use the {% static %} tag from the beginning.
Optional suggestion: Django's URL routing system
Your route in index.html is hard-coded to be "/". Django has a powerful URL referencing system to leverage. If you've defined the root URL / using Django too, you can refer to it by name. Docs: {% url %}, and for the back-end, reverse().

Tag or inherit the same code in Django template with minor changes

I have a bunch of code that I will need to use repeatedly on a page, and on multiple pages. For example, here is a shorter version of the code:
<a href="#"
data-toggle="popover"
title="{% for terms in s_terms %}{% if terms.slug == 'neuron' %}{{terms.title}}{% endif %}{% endfor %}"
data-content="{% for terms in s_terms %}{% if terms.slug == 'neuron' %}{{terms.para_one}}{% endif %}{% endfor %}">
Toggle popover
</a>
There is a lot more code in the block. Now, for obvious reasons I do not want to keep repeating such large chunks of code. I am a fan of the DRY approach.
However, I can't figure out how to render this same piece of code repeatedly. The only thing that would change is the word = "neuron" in there. I thought of using template tags, but that didn't work.
I tried saving the code as a separate file, and inherit it within my template, but then I can't change the keyword ('neuron'). I also tried creating a separate dynamic page, and include that in my Django template, but looks like the include tag only works for templates, and not for dynamic pages.
Can anyone help, please? Thank you, in advance.
You could use Django template built-in template tag include.
From the documentation:
Loads a template and renders it with the current context. This is a
way of “including” other templates within a template.
So, you can just extract your snippet in a separate template and then use it with:
{% include "snippet_template.html" %}
Additionally, you can pass a variable to the include template using the with keyword - you would use this to pass your word parameter:
{% include "snippet_template.html" with word="neuron" %}
As #bonidjukic wrote the include statement is what you search.
But include statement inside for-loop could reach one weakness of Django template Engine (vs Jinja). You include just variables, so it will be fast.
In the case of needing tags (like trans), Django will load tags at each include. Where Jinja will have global "tags".
So just be careful, with how you DRY you templates.

How do I load sorl's thumbnail template tag in all my templates

Given that sorl isn't an app directory wide and the template tag definition lives in the virtualenv dir
I want to be able to use {% thumbnail .... %} without having to use {% load thumbnail %} first. It can't be loaded in the layout apparently.
I know it is know critical but it would be nice %}
Copy paste the following code to an init.py that gets loaded,
from django import template
template.add_to_builtins('sorl.thumbnail.templatetags.thumbnail')
I don't think it's possible.
"When you load a custom tag or filter library, the tags/filters are only made available to the current template -- not any parent or child templates along the template-inheritance path."
So you'll have to declare {% load thumbnail %} in every template that uses the thumbnail tag.

Django: cannot pass variable to included template?

I got a problem where I want to use template including in Django.
Here is the real example:
I got 3 files:
home.html (will get the context variable passed from Views)
base.html (the skeleton template file)
and the header.html (included by base.html).
If I put the code below directly in base.html without including header.html, the {{title}} variable passed from home is correctly called. But if I include the header.html in base.html, the {{title}} variable's value cannot be called.
<title>{% block title %}{% endblock %} | {{ SITE_INFO_TITLE }}</title>
Is there any solution to this problem? Thanks.
Could you just pass in a variable within the {% include %} tag? It's documented here: https://docs.djangoproject.com/en/1.5/ref/templates/builtins/#include
{% include "name_snippet.html" with person="Jane" greeting="Hello" %}
As far as I know blocks and variable are distinct in django.
If you want to pass title as a context variable you have to set it using a declaration in base.html such as :
{% include "header.html"%}
Which in turn contains :
{% block title %} {{title}} {%endblock%}
You can also set it in home like this.
{% block title %} Home page {%endblock%}
But I also try to set in the template context.
Without the title block.
def test_view(ctx):
xa = { "title":"Sommaire"}
return render_to_response("test.html",xa)
I think you can also see the with template tag I think it is possible to set a context variable using this tag.
You can use Inclusion Tags to render an additional template from within a Django template. You can additionally pass the 'child' template context from the 'parent' template.
It's a little involved for your use case but it solves your problem. I tend to use it when I'm looping a list to render each item with a custom template. I can then reuse that template elsewhere without duplicating the markup if I need to render another item of the same type.

Django conditional template inheritance

I have template that displays object elements with hyperlinks to other parts of my site. I have another function that displays past versions of the same object. In this display, I don't want the hyperlinks.
I'm under the assumption that I can't dynamically switch off the hyperlinks, so I've included both versions in the same template. I use an if statement to either display the hyperlinked version or the plain text version. I prefer to keep them in the same template because if I need to change the format of one, it will be easy to apply it to the other right there.
The template extends framework.html. Framework has a breadcrumb system and it extends base.html. Base has a simple top menu system.
So here's my dilemma. When viewing the standard hyperlink data, I want to see the top menu and the breadcrumbs. But when viewing the past version plain text data, I only want the data, no menu, no breadcrumbs. I'm unsure if this is possible given my current design. I tried having framework inherit the primary template so that I could choose to call either framework (and display the breadcrumbs), or the template itself, thus skipping the breadcrumbs, but I want framework.html available for other templates as well. If framework.html extends a specific template, I lose the ability to display it in other templates.
I tried writing an if statement that would display a the top_menu block and the nav_menu block from base.html and framework.html respectively. This would overwrite their blocks and allow me to turn off those elements conditional on the if. Unfortunately, it doesn't appear to be conditional; if the block elements are in the template at all, surrounded by an if or not, I lose the menus.
I thought about using {% include %} to pick up the breadcrumbs and a split out top menu. In that case though, I'll have to include it all the time. No more inheritance. Is this the best option given my requirement?
You can put your hyperlinks inside a block that is overridden by the loading templates.
Let's say you have your framework.html like this:
{% extends "base.html" %}
<html>...<body>...
{% block hyperlinks %}
your hyperlinks here
{% endblock %}
rest of the code
</body></html>
You can then create something of a nolinks.html template and use it
{% extends "framework.html" %}
{# here you'll have everything from framework
but now we disable the breadcrumbs #}
{% block hyperlinks %}{% endblock %}
If you're getting the past data you can then use nolinks to render instead of framework.
I hope this helps.
From here: Any way to make {% extends '...' %} conditional? - Django
It can be done like this :
{% extends ajax|yesno:"ajax_base.html,main_base.html" %}
Or:
{% extends a_variable_containing_base_template_name %}
Which ever best suited for you.
Regards;