from django import template

register = template.Library()


@register.simple_tag
def paginator_url_replace(request, field, value):
    dict_ = request.GET.copy()
    dict_[field] = value
    return dict_.urlencode()


@register.simple_tag
def get_per_page(request):
    _dict = request.GET.copy()
    per_page = _dict.get('per_page', None)
    if per_page:
        return int(per_page)
    per_page = request.session.get('per_page', None)
    if per_page:
        return int(per_page)
    return 10