Jinja: {% set %} doesn't assign var to global context

[DriverX]

template:

{% set foo = "bar" %}
foo - {{ foo }}

{% for i in range(2) %}
     for:foo - {{ foo }}
     {% set foo = i %}
     for:foo - {{ foo }}
{% endfor %}

{{ foo }}

{% block test %}
    block:foo - {{ foo }}
    {% set foo = "baz" %}
    block:foo - {{ foo }}
{% endblock %}

foo - {{ foo }}

result:

foo - bar
    for:foo - bar
    for:foo - 0
    for:foo - 0
    for:foo - 1
foo - bar
    block:foo - bar
    block:foo - baz
foo - bar

wtf?

Please make a method of assigning a global variable.

[soulseekah]

Chipping in with some more details. This is what the code above looks like to get a feeling for what's happening inside:

from jinja2.runtime import LoopContext, TemplateReference, Macro, Markup, TemplateRuntimeError, missing, concat, escape, markup_join, unicode_join, to_string, identity, TemplateNotFound
name = None

def root(context, environment=environment):
   ...
    l_foo = 'bar'
    context.vars['foo'] = l_foo
    context.exported_vars.add('foo')
    yield u'\nfoo - %s\n\n' % (
        l_foo,
    )
    t_1 = l_foo
    l_i = missing
    for l_i in context.call(l_range, 2):
        if 0: yield None
        yield u'\n     for:foo - %s\n     ' % (
            l_foo,
        )
        l_foo = l_i
        yield u'\n     for:foo - %s\n ' % (
            l_foo,
        )
    l_foo = t_1
    l_i = missing
    yield u'\n\n'
    for event in context.blocks['test'][0](context):
        yield event
    yield u'\n\nfoo - '
    yield to_string(l_foo)

def block_test(context, environment=environment):
    l_foo = context.resolve('foo')
    if 0: yield None
    yield u'\n    block:foo - %s\n    ' % (
        l_foo,
    )
    l_foo = 'baz'
    yield u'\n    block:foo - %s\n' % (
        l_foo,
    )

blocks = {'test': block_test}
debug_info = '2=8&3=12&5=16&6=19&7=21&8=23&11=28&17=31&11=33&12=37&13=39&14=41'

More details:
Globals: http://jinja.pocoo.org/docs/api/#global-namespace
General: http://jinja.pocoo.org/docs/templates/#assignments
Implementation: http://jinja.pocoo.org/docs/api/#jinja2.runtime.Context
Another good explanation: http://stackoverflow.com/a/3355029/482864

Any ideas?

[mitsuhiko]

This is documented behavior.

[agoma8]

mitsuhiko,

We have the same problem as DriverX.
Yes, the use of "set" is documented, but, is it working?

Our example:

    {% set the_var = 'foo' %}
    {% for e in elements %}
        {% set the_var = 'YES' %}                           
        the var: {{ the_var }}
    {%- endfor %}
    the_var: {{ the_var }}

Result:

  the_var: YES
  the_var: YES
  the_var: foo

Can you help us? Thanks

[i5513]

http://stackoverflow.com/questions/4870346/can-a-jinja-variables-scope-extend-beyond-in-an-inner-block and http://stackoverflow.com/questions/9486393/jinja2-change-the-value-of-a-variable-inside-a-loop

I really don't understand why those hacks are neccesary, should be "local var" syntax or similar

Regards