How do you debug Mako templates?

Question

So far I\'ve found it impossible to produce usable tracebacks when Mako templates aren\'t coded correctly.

Is there any way to debug templates besides iterating for ever

Answer 1

Combining the two top answers with my own special sauce:

from flask.ext.mako import render_template as render_template_1
from mako import exceptions

app.config['MAKO_TRANSLATE_EXCEPTIONS'] = False    # seems to be necessary

def render_template(*args, **kwargs):
    kwargs2 = dict(**kwargs)
    kwargs2['config'] = app.config     # this is irrelevant, but useful
    try:
        return render_template_1(*args, **kwargs2)
    except:
        if app.config.get('DEBUG'):
            return exceptions.html_error_template().render()
        raise

It wraps the stock "render_template" function:

• catch exceptions, and
  • if debugging, render a backtrace
  • if not debugging, raise the exception again so it will be logged
• make config accessible from the page (irrelevant)