Cool. I will try that, thanks! I couldn't find any information on what kinds of comparisons can be done inside of a t-if statement. Is there any documentation for methods and operators?

Or the available variables, such as the "doc_model" you listed?

Updated my answer.

Thanks. I had read the QWeb section, but didn't notice that there was a separate QWeb Reports section.

Thank you very much for the answer. I spent so many hours fixing my problem before find this forum.

My code was:
<div t-if="o._name == 'sale.order'">

So I obtained odoo error:
AttributeError: 'NoneType' object has no attribute '_name'

you change the code like this. it will work
<div>
<t- t-if="o._name == 'sale.order'">
</t>
</div>