Is there a way to pass variables into Jinja2 parents?

I'm trying to pass some variables from the child page to the template. This is my python code:

    if self.request.url.find("&try") == 1:
        isTrying = False
    else:
        isTrying = True

    page_values = {
        "trying": isTrying
    }

    page = jinja_environment.get_template("p/index.html")
    self.response.out.write(page.render(page_values))

The template:

<html>
  <head>
    <link type="text/css" rel="stylesheet" href="/css/template.css"></link>
    <title>{{ title }} | SST QA</title>

    <script src="/js/jquery.min.js"></script>

  {% block head %}{% endblock head %}
  </head>
  <body>
    {% if not trying %}
    <script type="text/javascript">
    // Redirects user to maintainence page
    window.location.href = "construct"
    </script>
    {% endif %}

    {% block content %}{% endblock content %}
  </body>
</html>

and the child:

{% extends "/templates/template.html" %}
{% set title = "Welcome" %}
{% block head %}
{% endblock head %}
{% block content %}
{% endblock content %}

The problem is, I want to pass the variable "trying" into the parent, is there a way to do this?

Thanks in advance!

Solution

I do not understand your problem. When you pass variables to the context (as you do with trying) these variables will be available in the child and the parent. To pass title to the parent, you have to use inheritance, sometimes in combination with super : http://jinja.pocoo.org/docs/templates/#super-blocks

See also this question: Overriding app engine template block inside an if