dev_middleware.py

"""
Originaly code was taken from: http://djangosnippets.org/snippets/290/
But I was made some improvements like:
- print URL from what queries was
- don't show queries from static URLs (MEDIA_URL and STATIC_URL, also for /favicon.ico).
- If DEBUG is False tell to django to not use this middleware
- Remove guessing of terminal width (This breaks the rendered SQL)
"""

from clint.textui import colored, columns, indent, puts
from django.conf import settings
from django.core.exceptions import MiddlewareNotUsed
from django.db import connection


INDENTATION = 2


class SQLPrintingMiddleware(object):
    """
    Middleware which prints out a list of all SQL queries done
    for each view that is processed. This is only useful for debugging.
    """
    def __init__(self):
        if not settings.DEBUG:
            raise MiddlewareNotUsed

    def process_response(self, request, response):
        if (len(connection.queries) == 0 or
                request.path_info.startswith('/favicon.ico') or
                request.path_info.startswith(settings.STATIC_URL) or
                request.path_info.startswith(settings.MEDIA_URL)):
            return response

        with indent(INDENTATION):
            puts(colored.magenta('[SQL Queries for] ') + colored.blue(request.path_info))
            puts()
            total_time = 0.0
            for query in connection.queries:
                nice_time = '[{0}]'.format(query['time'])
                nice_sql = query['sql'].replace('"', '').replace(',', ', ')
                total_time = total_time + float(query['time'])
                puts(
                    columns(
                        [colored.red(nice_time), 10],
                        [colored.white(nice_sql), 120],
                    )
                )
                puts()
            puts(colored.green("[TOTAL TIME: %s seconds (%s queries)]" % (
                str(total_time), str(len(connection.queries)))))
        return response