templatecontext.py 文件源码

def include_filter(config:Configurator, name:str, func: t.Callable, renderers=(".html", ".txt",)):
    """Register a new Jinja 2 template filter function.

    Example::

        import jinja2

        @jinja2.contextfilter
        def negative(jinja_ctx:jinja2.runtime.Context, context:object, **kw):
            '''Output the negative number.

            Usage:

                {{ 3|neg }}

            '''
            neg = -context
            return neg


    Then in your initialization:::

        include_filter(config, "neg", negative)

    :param config: Pyramid configurator

    :param name: Filter name in templates

    :param func: Python function which is the filter

    :param renderers: List of renderers where the filter is made available

    """

    def _include_filter(name, func):

        def deferred():
            for renderer_name in renderers:
                env = config.get_jinja2_environment(name=renderer_name)
                assert env, "Jinja 2 not configured - cannot add filters"
                env.filters[name] = func

        # Because Jinja 2 engine is not initialized here, only included here, we need to do template filter including asynchronously
        config.action('pyramid_web-include-filter-{}'.format(name), deferred, order=1)

    _include_filter(name, func)