truncate characters in a HTML element - Django Templates

Question

In my django templates i have a list of objects which is rendered as follows:

<li class="keys">
{% for key in job.key_list|slice:":2" %}
    {% if not forloop.last %}
        <a href="/keys/{{ key.id }}/{{ key }}/">{{ key }}</a>,
    {% else %}
        <a href="/keys/{{ key.id }}/{{ key }}/">{{ key }}</a>
    {% endif %}
{% endfor %}
</li>

This outputs the list as:

some_key, some_key_two

I want to truncate the number of characters to 20 but on the whole list. So that it renders something like:

some_key, some_key_t...

I am aware about the truncatechars and truncatewords filters available in django but they work on a string variable within the template.

How do i go about implementing this functionality ?

It's not really clear what you're after. Do you want to truncate the `key` in the href part of the `` or the `key` in the text of the `` ? — Henrik Andersson, May 20 '13 at 09:04
i do not want to truncate a single object, For example: if i use `truncatechars` to 6 chars on elements say (Stack Overflow and Stack Exchange) it will output. `Stack ..., Stack ...`. I want to truncate the characters in the rendered list so that if i truncate on 20 characters it looks like `Stack Overflow, Stac...`. So here the total number of characters shown within the `
Don't think django can help you here. Try to do that through CSS by specifying `max-width` and `overflow: hidden`. Or format the strings in view and pass them in list to template. — Rohan, May 20 '13 at 09:21
@Rohan: Yeah I thought so, maybe an easier solution would be to use a jquery plugin like expander. — Amyth, May 20 '13 at 09:33

score 1 · Answer 1 · answered May 20 '13 at 09:34

Wow, that's a strange requirement. You would have to implement this as a template tag or custom filter that takes a list and transforms it.

@register.filter(name='truncatinator')
def truncatinator(value, arg):
    strings = ",".join(value)
    if len(strings) >= arg:
        part = strings[0:19] + "..."
    return part.split(',')

and use it like this {% for object in job.key_list|truncatinator:"20" %}

What you will notice though is that you will loop over a string list here instead of your objects which will give you this disadvantage: You won't have access to your .id. This could be modified though as well.

I would do this with Javascript instead but I don't think that Django should be responsible for this overall.

@Amyth I don't know actually but I made a small javascript for you. I based it on jquery. Why? I don't know. Here ya go anyways: http://jsfiddle.net/sNEPA/2/ - It's not great since it uses global variables but you could hide it in a function and be done with it. — Henrik Andersson, May 20 '13 at 10:00

truncate characters in a HTML element - Django Templates

1 Answers1