Django. Write notifications dynamically and render them correctly

Question

I asked this question last week and haven't got an answer yet. Now I realize that it doesn't point to the real problem. So, I want to write a notification for a user and then render it to the template. My idea is to write all the html in the views.py file and then in the template just use the {html|safe} tag. I want the notifications to be like this:

user voted up your post on topic.

So, I tried to write the html as a string and use the %s to replace the usernames and the names of the topics, like this:

string_to_render = "<a href = '{% url ... %}'> %s </a> voted up your <a href = '{% url ... %}'> post </a> on the <a href = '{% url ... %}'> %s </a>" %(user, topic)

The %s is there to replace the user and the topic names. But python also understands django's "% url" as an unsigned decimal replacement and I get the error:

%u format: a number is required, not unicode

So, if there isn't an easy solution to this problem. I am open to suggestions about how to render notifications. Maybe I shouldn't write the whole notification before rendering it and I should try writing them on html and use many content variables? That would also require many {% if-else %} template tags cause vote-up is only one of the notifications I would like to give to the user. That is just an idea, but surely there is a better way to do it.

Thanks in advance for your help.

Why do you want to write the HTML in the views file? We have templates for a reason, and that reason is to avoid exactly the problems you're having. — Daniel Roseman, May 26 '14 at 20:42

score 1 · Answer 1 · edited May 23 '17 at 10:32

1

You need to escape the % near the url template tag:

string_to_render = "<a href = '{%% url ... %%}'> %s </a> voted up your <a href = '{%% url ... %%}'> post </a> on the <a href = '{%% url ... %%}'> %s </a>" % (user, topic)

Though, as @Daniel Roseman noted, it is better to create a template, include it into the main html template and pass user and topic inside the context while rendering.

edited May 23 '17 at 10:32

Community

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answered May 26 '14 at 20:42

alecxe

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alecxe thanks for your answer, it didn't work though. It did escape the % but it didn't render a correct hyperlink. I guess it is a problem with the `{{html|safe}}`: I got something like `"` and then an obvious 404 when I clicked the link. Weird. Anyway I will include an html template and pass the variables to it as @Daniel said. However, I will need 16 `{% if-else %}` filters to detect the notification type and use the correct html (There are 12 types of notifications divided in 4 groups). Guess that is ok. – Alejandro Veintimilla May 26 '14 at 22:44
@alejoss well, if you would name your templates good, e. g. `notification_.html`, you could avoid multiple if/elif/else. Though I haven't seen what are these blocks.. – alecxe May 26 '14 at 23:16

Django. Write notifications dynamically and render them correctly

1 Answers1