recursive template calls

[Shannon -jj Behrens]

Hi,

I'm trying to build ye ol' bulletin board application to try out
Django. I'm having a hard time outputting the hierarchy of messages.
I can't figure out how to use recursion in templates. I also need to
be able to treat a template "like a function" passing arguments. How
should I be thinking about this problem? Here's the app written in
another framework: <http://seamstress.norcalttora.com/>.

Thanks!
-jj

[Cheng Zhang]

Please search the previous email archive for discussion on such topic
like "tree view".
In fact, there is a wiki page for an implementation as well.

[Jamie Scheinblum]

that's funny. they answered how to do the tree thing, but the wiki
basically says no recursion... I should look into the % recurse %
keyword tho.

-j

[Max Battcher]

Jamie Scheinblum wrote:
> that's funny. they answered how to do the tree thing, but the wiki
> basically says no recursion... I should look into the % recurse %
> keyword tho.

The {% recurse %} is a custom tag from the Custard work at Greenpeace,
not a Django-contributed tag. It is Open Source under the LGPL.

--
--Max Battcher--
http://www.worldmaker.net/

[Shannon -jj Behrens]

Sorry, guys, I'm confused. I *did* search before posting, but wasn't
able to find a full answer. I saw someone doing the bulletin board
example, but I never found out how to recursively call a template.
Must I use the non Django {% recurse %} custom tag?

Thanks,
-jj

[Julio Nobrega]

You don't *need* recursion on templates for threaded messages like
your example app, that's exactly the point :)

--
Julio Nobrega - http://www.inerciasensorial.com.br

[Shannon -jj Behrens]

> You don't *need* recursion on templates for threaded messages like
> your example app, that's exactly the point :)

Julio, with all due respect for your programming prowess, I *like*
recursion. It can often make hard problems easy, even when generating
HTML.

Anyway, I figured out how to solve the problem *using recursion*, and
I blogged about it:
<http://jjinux.blogspot.com/2006/02/python-recursion-in-django-templates.html>.
It works, but it's nowhere near as elegant as simply being able to
add a function to the template that I could call recursively. :-/

Best Regards,
-jj

[Robert Wittams]

This is ridiculous. Something like this seems a lot easier to me...

templatetags.py:

register = template.Library()

@register.inclusion_tag('comment')
def show_comment(comment):
{'comment': comment}

comment.html:

{% load comments %}
{% comment.subject %}
{% comment.body %}
{% for child in comments.children %}
{%show_comment child %}
{% endfor %}

page.html:

{% show_comment comment %}

The moral of the story : custom template tags aren't really an optional
bit of the framework. If you don't learn how to use at least simple_tag
and inclusion_tag, you will get annoyed quite often.

Robert

[Luke Plant]

On Saturday 11 February 2006 12:08, Robert Wittams wrote:

> If you don't learn how to use at least
> simple_tag and inclusion_tag, you will get annoyed quite often.

That's fairly easy for you to say -- you wrote them! Documentation on
these tags is fairly hard to come by - nothing in the official docs,
nothing in the source code, nothing (that I could find) in the wiki. I
eventually found this:

http://code.djangoproject.com/changeset/1410

Any chance we could put that somewhere more prominent?

Luke

--
Life is complex. It has both real and imaginary components.

Luke Plant || L.Plant.98 (at) cantab.net || http://lukeplant.me.uk/

[Shannon -jj Behrens]

I think it's unfortunately that template writers have to resort to
Python just to package up a bit of HTML into a function, but that's
just my opinion.

-jj

[Jonathan Ellis]

On 2/13/06, Shannon -jj Behrens <jji...@gmail.com> wrote:

I think it's unfortunately that template writers have to resort to
Python just to package up a bit of HTML into a function, but that's
just my opinion.

 

OTOH Python is a lot cleaner than attempts at "designer-friendly" mini-languages.  (CFScript, ActionScript, ...)

-Jonathan

[luke....@gmail.com]

Shannon -jj Behrens wrote:

> I think it's unfortunately that template writers have to resort to
> Python just to package up a bit of HTML into a function, but that's
> just my opinion.

In the normal case, you can just use the {% include %} tag, so you
don't have to resort to Python. It is the recursion that is bringing
in that necessity.

Luke