Get javascript variable's value in Django url template tag

It is known that there's a DRY way of directing to an URL by using django template tag "url", say

{% url "someview" arg1=X %}

Here, I want "X" to be the value of a javascript variable, say tmp. But the following doesn't work

<script>
    ...{% url "someview" arg1=tmp %}...
</script>

How should I get the value inside a template tag?

I found a trick that might work under most circumstances:

var url_mask = "{% url 'someview' arg1=12345 %}".replace(/12345/, tmp.toString());

It's clean, and it doesn't break DRY principle.

Just making it clear so next readers can have a comprehensive solution. In regard to the question, this is how I used Mike Lee solution for an example case which is redirecting with Javascript to a new page with a parameter in a variable named tmp:

window.location = "{% url 'your_view_name' 1234 %}".replace(/1234/, tmp.toString());

one easy way to do this is

<div id="test" style="display: none;">
 {% url 'some_url:some_sub_url'%}
</div>


<script>
  url_mask = $( "#test" ).html()
</script>

var name = "{% url 'your_view_name' pk=0 %}".replace('0', name_variable);