How do I DRY up common text in a Django template? - django

I have some static text that needs to show up at 2 locations within a template.
For example:
<div>
{% if something %}
This is a static text
{% else %}
Something else happened
{% endif %}
</div>
... more html
<span>
{% if something %}
This is a static text
{% else %}
Something else happend
{% endif %}
</span>
I can do the above by duplicating the above text at 2 different locations in my template file(as shown above).
I could also create a model which will store the text(This is DRY but cost a call to the DB for a simple task)
I'm thinking of using include template but that's probably not the best way to achieve my goal.
What's the best way to do it?

Definitely use Inclusion Tags:
http://docs.djangoproject.com/en/dev/howto/custom-template-tags/#inclusion-tags
The tag file would either be something super simple like just the text "This is a static text" or the entire block:
{% if something %}
This is a static text
{% else %}
Something else happened
{% endif %}
"something" can be passed as a variable to the template tag so you can use that entire block in a variable way.

I use the django internationalization to do that. So in my apps/template I just write the key, and in the .po files is the value of the keys.
{% load i18n %}
<div>
{% if something %}
{% trans "static" %}
{% else %}
{% trans "something else" %}
{% endif %}
</div>
And in my .po file:
msgid "static"
msgstr "This is a static text"
msgid "something else"
msgstr "Something else happened
Besides useful for multi-language, it's much easier for copy writing just in case you want to change it in the future because you can just look unto one file instead of browsing several templates.

There are several ways, but it probably depends on what the text is and how often it will be used. It's hard to recommend a specific choice without full details
Create a custom template tag (this one makes the most sense based on how you've described your problem above).
Create a base template which has the text in it at the correct location and then inherit off of it for your "2 locations"
Put the static piece of text in a settings file and pass it to the template renderer via Context (probably not the best idea, but depending on what you're doing it could be a possibility)

You could use flatblocks : http://github.com/zerok/django-flatblocks
or chunks : http://code.google.com/p/django-chunks/
Those may be overkill for your problem, since they store your snippets in the database, but they add the benefit of making it possible to edit them via the admin.
{% load chunks %}
<div>
{% if something %}
{% chunk "something" %}
{% else %}
{% chunk "something_else" %}
{% endif %}
</div>
There are lots of forks or similar projects, for example:
http://bitbucket.org/hakanw/django-better-chunks/
http://github.com/bartTC/django-generic-flatblocks

I have a file like Java properties that I use for all of my resource strings. I just serve up the one that I want. Keeping these in one place also makes translating easy.
Ex.:
welcome_msg="hello user!"
thank_you="thank you"
goodbye_msg="goodbye, " + thank_you

If the included text gets bigger, use an 'include' tag.
{% include "myapp/helptext.html" %}
GrtzG

Related

Django nested templates

In trying to keep with DRY, I'm setting up my Django project HTML files now. I have successfully extracted most repeated information to my base.html page. On most (but not all) of my pages, my content is displayed within a general 'panel' which is basically just a container set-up with styling, but it's got a few div-tags to it so it looks a bit ugly and I'm having to type out the exact same code out several times on each page.
My idea was to extract this to a 'panel.html' then call it whenever I need it, for example some pages might just have one 'panel' whereas my dashboard (it's an administrative site) will have maybe 15+. So it seemed a better idea and cleaner to not have to type out all this code each time I need to set up a 'panel'.
My ideal page would look something like..
{% extends 'base.html' %}
{% block content %}
{% extends 'panel.html' %}
{% block panel_content %}
Panel content...
{% endblock panel_content %}
{% extends 'panel.html' %}
{% block panel_content %}
Second panel content
{% endblock panel_content %}
{% endblock content %}
I know I can't use extends multiple times but I'm using it just as an example for what it is I'm trying to achieve.
I am going to potentially have hundreds of these identical 'panels' across my site but each containing different content and it would be so much cleaner if I could just have one stored somewhere in a HTML file and call it however many times I need.
Is there a way to do this?
You can use include
{% include "panel.html" %}
I should mention that too many include statements create a performance issue.

Adding an if statement to django-cms template tag

I'm probably missing something very obvious but can't see anything in the documentation. I have a carousel with a and each will hold an image. However I've added 6 but I want to add an if statement so if an Image has not been added you don't see a blank space, where there is no content inside the .
Here is what i've tried so far:
{% if "Carousel 1" %}
<li>
{% placeholder "Carousel 1" %}
</li>
{% endif %}
Attempt 2:
{% placeholder "Carousel 1" as cara1 %}
{% if cara1 %}
<li>
{{ cara1 }}
</li>
{% endif %}
Not sure if there is something differnt i need to be doing for the django-cms template tags?
Any help would be much appreciated. Docs here - http://docs.django-cms.org/en/latest/advanced/templatetags.html#placeholder
Not to be rude, but your approach is way, way off :)
Placeholders hold Content Plugins. Content Plugins are responsible for how they render their contents.
My advice would be to create or find a carousel content type plugin. This plugin will hold multiple images or "CarouselImage" model instances that you can iterate over, and also specify a template with which to render itself.
In this template resides the conditional statement you're wanting to check for. Placeholders are just that - places held for content plugins.

Can I specify a multiline context variable/parameter when {% include %}ing a template?

I know that it is possible to set context variables when including a Django template from another template using
{% include "default_table.html" with table_header=table_header1 table_data=table_data1 %}
or
{% with "My data" as table_data %}
{% include 'default_table.html' %}
{% endwith %}
My issue with this is that both approaches don't let me define multiline variables (unless they are based on a previous multiline variable of course).
My specific usecase is this
<!-- widget.html -->
<div class="box">
<div class="title">{{ title }}</div>
<div class="title">{{ body }}</div>
</div>
and I'd like to be able to set a longer text for the body context variable. This will make is possible for me to reuse common widget HTML in various places. Can this be done?
I've been searching a bit on http://djangosnippets.org for an über {% with ... %} template tag, but haven't found any so far.
This Django snippet kinda solves my issue: http://djangosnippets.org/snippets/1860/ But I'd love to be able to set context variables instead of defining {% localblock step_ready_js %}{% endlocalblock %} in my widget HTML.

Django template inclusion

The template inheritance page on the django site doesn't really solve my problem (Django 1.2).
My base page looks like:
...
<div class="grid_12" id="content">
{% block content %}{% endblock %}
</div>
...
{% block javascript %}{% endblock %}
I have another template that defines content for these:
{% block content %}
animated sidebar
{% endblock %}
...
{% block javascript %}
alert('hello');
{% endblock %}
This is something like an animated sidebar, so I don't want to extend the base template since it's auxiliary to the main content of the page. If I just use "include", the entire thing is put where the "include" tag is placed - as a result the javascript doesn't run because it's included before one of its dependencies.
What's the best way to solve this?
EDIT
Sorry, I didn't make myself clear.
I have my content pages which render a template that extends "base.html". In "base.html" I want to include a sidebar template that needs to append blocks in "base.html". So I've tried just putting include "sidebar.html" into "base.html", but it just inserts the whole thing where the "include" tag is. What I want it to do is append the blocks in "base.html", which may themselves have been populated by "page.html".
Maybe it's important to say that "sidebar.html" is entirely static - i.e. there's no callable associated with it. So perhaps this question should really be "How can I include a static template into base.html so it will append to blocks in base.html regardless of the output of the actual view that processes the request?"
I think you mean you want to append to a block? You can put {{ block.super }} where you want the inherited content to go. e.g.:
{% block javascript %}
{{ block.super }}
alert('hello');
{% endblock %}
You should only use {% block foo %} tags to extend blocks in a base template, so I'm not clear what you mean when you say you don't want to extend it.
The code, as you've entered it, should render to
...
<div class="grid_12" id="content">
animated sidebar
</div>
...
alert(hello)
Unless you want to append the content (as in Matt's answer) it's not clear what you want to happen.
You shoud be using something like jQuery to trigger execution only after the page is fully loaded. Include jQuery library in the document header and then somewhere:
$(document).ready(function() {
//your code goes here
});

Indeterminite number of apps/widgets in Django template

I'm working on a site that will have a bunch of pages with an indeterminate amount of "apps" on each page. Something like a calendar app, and a random picture app, or whatever, each in a neat little box. While it's possible to write a template with a bunch of if tags that include other templates, this is a bit of a hassle. I'd like to pass in some variables and have forms on some of these apps, so it would get out of hand quickly. Writing custom inclusion tags will be better than {% include x %}, but it would still be a lot of if statements and writing out every possible app for each page.
Is there any way to loop over something like inclusion tags and include only those that are relevant? Any other completely different solution that I'm missing?
What I'm trying to avoid, whether I use {% include %} or inclusion tags, is this:
{% if apps.calendar %}
{% include "calendar.html" %}
{% endif %}
{% if apps.pictures %}
{% include "pictures.html" %}
{% endif %}
This would mean we'd have to update templates any time a new app was added. What would be nice is something like:
{% for app in apps %}
{% call appropriate include or inclusion tag %}
{% endfor %}
With very few exceptions we use our custom tags all over the place, so we deal with this by simply placing the following in the app/__init__.py file.
from django import template
template.add_to_builtins('content.templatetags.local_tags')
template.add_to_builtins('utils.cachetemplate')
So all of the pages have them available by default. Doesn't seem to impact performance and we use tag names that are unlikely to interfere with other stuff we might include. It's lazy but it works.
Update: OK, I think I better understand what you want. One way of doing this (although I don't really recommend it) is to put the check for the variables inside the included templates. This means you will always have the overhead of including the template, but it will make your other pages marginally less cluttered.
So instead of this in your main file:
{% if apps.calendar %}
{% include "calendar.html" %}
{% endif %}
you simply have:
{% include "calendar.html" %}
and in "calendar.html" you have:
{% if apps.calendar %}
whatever you do for your calendar app
{% endif %}
Update 2:
The last bit of code you show could be done as follows. This takes advantage of the the fact that {% include arg %} "resolves" its argument. This means it can be a variable or a method reference that returns a usable string value that is a template name.
{% for app in apps %}
{% include app %} <!-- or perhaps {% include app.template %} -->
{% endfor %}
Note: Django's template code does not handle top level callables correctly. This means your context cannot pass a reference to a function and expect it to be called and it's output inserted when referenced in a template. Ie. in the example above your list of apps may not be simple functions which you wish to be called. To work as expected a function reference must be either a member of a list or dict, or it must be a method of an object that is passed. We MonkeyPatched this problem long ago because we use curried functions in cached template fragments to defer some heavy DB work. This ticket has been open for over 2 years.