Content between an open with tag (e.g., {% with var1=value2 var2=value2… %}) and close endwith tag (e.g., {% endwidth %}) have access to the variables defined in the open with tag.
The with tag is useful for reusing the results of an expensive method. Consider the following template:
{{ jokes.count }} joke{{ jokes.count|pluralize }} that match your search.
In the preceding code, jokes.count has to be evaluated twice. The following code assigns jokes.count to joke_count and then uses the result within the block:
{% with joke_count=jokes.count %}
{ joke_count }} joke{{ joke_count|pluralize }} that match your search.
{% endwith %}
Commentary
Django tags cannot span multiple lines.
It might be tempting to write an open
withtag like this:Bad code:
{% with var1 = 'very long value' var2 = 'very long value' var3 = 'very long value' %}But Django will not recognize that as a tag and thus will be surprised by the
endwithtag. You will end up with an error like this one: