Extracting a value from inside a django loop

问题

I have a django app where i am using the following in the templates:

{% load mptt_tags %}
<ul>
    {% recursetree nodes %}
        <li>
            {{ node.name }}
            {% if not node.is_leaf_node %}
                <ul class="children">
                    {{ children }}
                </ul>
            {% endif %}
            {% if node.is_leaf_node %}
                <span ng-bind="progid = {{node.program_id}}"></span> 
            {% endif %}
        </li>
    {% endrecursetree %}
</ul>

The values of the node will be gone once the recursion takes place. I would like to know how to extract a values outside this loop in the template such that it can be used in another template?

I tried something like this:

<span ng-bind="progid = {{node.program_id}}"></span>

But when i refer it outside the loop, it does not work!

UPDATE:

as you can see, i am trying to use the value of progid outside the loop.

回答1:

You may try to write a custom template tag for this. See the docs.

https://docs.djangoproject.com/en/dev/howto/custom-template-tags/

Assuming your assignment tag is named assign, you would then do

{% recursetree nodes %}

    {% assign_node node %}

{% endrecursetree %}

And then use the my_node

{{ my_node.program_id }}

Your template tag code should be getting the context. The main context is always the context.dicts[0].

Your template tags module (named bar_tags):

from django import template

register = template.Library()

@register.assignment_tag(takes_context=True)
def get_dummy_nodes(context, *args, **kwargs):
    """
    Just get some dummy objects to work with.
    """
    class Node(object):
        name = None
        def __init__(self, program_id):
            self.program_id = program_id

    nodes = []
    for i in range(0, 10):
        nodes.append(Node(i))

    return nodes

@register.simple_tag(takes_context=True)
def assign_node(context, node, *args, **kwargs):
    """
    Puts your variable into the main context under name ``my_node``.
    """
    context.dicts[0]['my_node'] = node
    return ''

Your template:

<html>
<body>
{% load bar_tags %}

{% get_dummy_nodes as nodes %}

{% for node in nodes %}
    {% assign_node node %}
{% endfor %}

my_node {{ my_node.program_id }}

</body>
</html>

Note: you should better be doing such things in a view.

来源：https://stackoverflow.com/questions/24247130/extracting-a-value-from-inside-a-django-loop

标签

django

angularjs

django-templates