Source code for wheezy.html.utils

""" ``utils`` module.
"""

from datetime import date, datetime


def escape_html(s):
    """Escapes a string so it is valid within HTML. Converts `None`
    to an empty string. Raises TypeError is `s` is not a string
    or unicode object.

    >>> html_escape(None)
    ''

    >>> escape_html('&<>"\\'')
    "&amp;&lt;&gt;&quot;\'"
    """
    if s is None:
        return ""
    try:
        return (
            s.replace("&", "&amp;")
            .replace("<", "&lt;")
            .replace(">", "&gt;")
            .replace('"', "&quot;")
        )
    except AttributeError:
        raise TypeError(
            "expected string or unicode object, "
            "%s found" % s.__class__.__name__
        )


escape_html_native = escape_html

try:
    from wheezy.html.boost import escape_html

    html_escape = escape_html  # pragma: nocover
except ImportError:  # pragma: nocover
    html_escape = escape_html


def html_id(name):
    return name.replace("_", "-")


def format_value(value, format_spec=None, format_provider=None):
    """Formats widget value.

    ``format_provider`` - a callable of the following form::

        def my_formatter(value, format_spec):
            return value_formatted

    >>> str(format_value(date(2012, 2, 6), '%m-%d-%y'))
    '02-06-12'
    >>> format_value(date(2012, 2, 6),
    ...         format_provider=lambda value, ignore:
    ...         value.strftime('%m-%d-%y'))
    '02-06-12'
    >>> list(map(str, format_value([1, 2, 7])))
    ['1', '2', '7']
    >>> format_value([])
    ()

    If format provider is unknown apply str.

    >>> str(format_value({}))
    '{}'
    """
    # TODO: probably there is better check since attribute check for
    # __iter__ is not valid in python 3.2, str support it.
    if isinstance(value, (list, tuple)):
        try:
            if format_provider is None:
                formatter_name = type(value[0]).__name__
                format_provider = format_providers[formatter_name]
            return tuple(format_provider(item, format_spec) for item in value)
        except IndexError:
            return tuple([])
    else:
        if format_provider is None:
            formatter_name = type(value).__name__
            if formatter_name in format_providers:
                format_provider = format_providers[formatter_name]
            else:
                return str(value)
        return format_provider(value, format_spec)


def str_format_provider(value, format_spec):
    return str(value)


min_date = date(1900, 1, 1)
min_datetime = datetime(1900, 1, 1)


def date_format_provider(value, format_spec=None):
    """Default format provider for ``datetime.date``.

    Requires year >= 1900, otherwise returns an empty string.

    >>> date_format_provider(date.min)
    ''
    >>> date_format_provider(min_date)
    '1900/01/01'
    >>> date_format_provider(date(2012, 2, 6))
    '2012/02/06'
    """
    if value < min_date:
        return ""
    # Python 2.4, 2.5
    # TypeError: strftime() argument 1 must be str, not unicode
    return value.strftime(str(format_spec or "%Y/%m/%d"))


def datetime_format_provider(value, format_spec=None):
    """Default format provider for ``datetime.datetime``.

    Requires year >= 1900, otherwise returns an empty string.

    >>> datetime_format_provider(datetime.min)
    ''
    >>> datetime_format_provider(min_datetime)
    '1900/01/01 00:00'
    >>> datetime_format_provider(datetime(2012, 2, 6, 15, 17))
    '2012/02/06 15:17'
    """
    if value < min_datetime:
        return ""
    # Python 2.4, 2.5
    # TypeError: strftime() argument 1 must be str, not unicode
    return value.strftime(str(format_spec or "%Y/%m/%d %H:%M"))


format_providers = {
    "str": lambda value, format_spec: html_escape(str(value)),
    "unicode": lambda value, format_spec: html_escape(value),
    "int": str_format_provider,
    "Decimal": str_format_provider,
    "bool": str_format_provider,
    "float": str_format_provider,
    "date": date_format_provider,
    "time": lambda value, format_spec: value.strftime(
        str(format_spec or "%H:%M")
    ),
    "datetime": datetime_format_provider,
    "NoneType": lambda value, format_spec: "",
}