Learning About Django Templates

Posted by ryan

January 21, 2009

I was working on a template last night to handle a generic view. I started by going into the console (managey.py shell) to poke around at the model I wanted to use. From that session, I copied the following snippet to use in the template.

project.projectimage_set.all()[0].image.url

I added this to the template and it looked like this.

{% for project in object_list %}
<div class="project">
   <div class="project-image">
      <img src="{{ project.projectimage_set.all()[0].image.url }}" alt="" />
   </div>
   <div class="project-info">
      {{ project.name }}
      {{ project.link|urlize }}
      {{ project.description }}
   </div>
</div>
{% endfor %}

When running the template I received the error: “Could not parse the remainder: (0)”. I hadn’t seen this before and searched Google to get the answer. It didn’t look good on the first search. The answer was repeated in different results, originating from a Google group. The answer given (and I’m paraphrasing) was “Django templates don’t use Python code. You’re doing it wrong. Go write a template tag or custom method.” I read through the link a few times and couldn’t find the answer I wanted to hear. I figured this was common, and I thought a web framework for people with deadlines would not require me to write too much code to get to a property.

I went back to the documentation and looked around and still didn’t find anything that showed me how to access the properties further down on the related model so I went back to Google. This time I found an answer!

I’m not going to put on like I know what’s going on here. I can think about how somewhere underneath in the template language there’s an implementation of __getattr__, but I didn’t go and research it. It’s almost 0200 and sleep is calling. Because it was difficult for me to find, I thought I would just post this and maybe it would help the next guy stumble upon removing the () and [ ].

Here is the working code:

{% for project in object_list %}
<div class="project">
   <div class="project-image">
      <img src="{{ project.projectimage_set.all.0.image.url }}" alt="" />
   </div>
   <div class="project-info">
      {{ project.name }}
      {{ project.link|urlize }}
      {{ project.description }}
   </div>
</div>
{% endfor %}