import json


def register_template_filters(app):
    app.template_filter("strftime")(_strftime)
    app.template_filter("dumps")(_dumps)


def _strftime(value, fmt="%m/%d/%y, %-I:%M %p"):
    if not value:
        return ""
    return value.strftime(fmt)


def _dumps(value):
    return json.dumps(value, sort_keys=True)