paginator

paginator.py

class VTPaginator(dict):
    def __init__(self, num_rows, **kwargs):
        defaults = {
            'offset': 0,
            'limit': 10,
            'view_num': 11,
            'splitter': '...',
            'view_one_page': False,
            'min_limit': 10,
            'max_limit': 50,
            'params': None,
            'offset_name': 'offset',
            'is_range': False
        }

        defaults.update(kwargs)
        self.update(defaults)

        self['num_rows'] = num_rows

        if self['limit'] < self['min_limit']:
            self['limit'] = self['min_limit']

        if self['limit'] > self['max_limit']:
            self['limit'] = self['max_limit']

        if self['offset'] > self['num_rows']:
            self['offset'] = self['num_rows'] - self['limit']

        if self['offset'] < 0:
            self['offset'] = 0

        self['num_pages'] = int(math.ceil(float(self['num_rows'])
                                          / self['limit']))

        self['curr_page'] = int(math.ceil(self['offset'] / self['limit']))

        self['next_page'] = self['curr_page'] + 1
        if self['next_page'] >= self['num_pages']:
            self['next_page'] = self['num_pages'] - 1

        self['prev_page'] = self['curr_page'] - 1
        if self['prev_page'] < 0:
            self['prev_page'] = 0

        self['offset_next_page'] = self['limit'] * self['next_page']
        self['offset_prev_page'] = self['limit'] * self['prev_page']
        self['offset_last_page'] = self['limit'] * (self['num_pages'] - 1)

        self['curr_page'] += 1
        self['next_page'] += 1
        self['prev_page'] += 1

        if self['params']:
            items = {}

            for key, val in self['params'].iteritems():
                if isinstance(val, str) or isinstance(val, unicode):
                    items[key] = val.encode('utf-8')
                else:
                    items[key] = val

            self['params'] = items

        self['is_last'] = (self['offset'] + self['limit']) >= self['num_rows']

        self['page_xrange'] = self._get_page_range()
        self['page_range'] = list(self._get_page_range()) if self[
            'is_range'] else None

    def _page(self, i):
        offset = (i - 1) * self['limit']
        params = dict(self['params'])
        params[self['offset_name']] = offset

        return {
            'n': i,
            'o': offset,
            'url_params': urllib.urlencode(params),
            'is_current': self['curr_page'] == i
        }

    @property
    def first_page(self):
        return self._page(1)

    @property
    def last_page(self):
        return self._page(self['num_pages'])

    @property
    def next_page(self):
        return self._page(self['next_page'])

    @property
    def prev_page(self):
        return self._page(self['prev_page'])

    def _get_page_range(self):
        num_pages = self['num_pages']
        splitter = {'is_splitter': True,
                    'splitter': self['splitter']}
        view_num = self['view_num']
        curr_page = self['curr_page']

        if num_pages <= view_num:
            for i in xrange(1, num_pages + 1):
                yield self._page(i)

        else:
            df = view_num / 2
            if curr_page <= df:
                for i in xrange(1, view_num):
                    yield self._page(i)

                yield splitter
            elif curr_page >= num_pages - df:
                yield self._page(1)
                yield splitter

                for i in xrange(num_pages - view_num + 2, num_pages):
                    yield self._page(i)

            else:
                yield self._page(1)

                if curr_page != df + 1:
                    yield splitter

                for i in xrange(curr_page - df + 1, curr_page + df):
                    yield self._page(i)

                if curr_page != num_pages - df:
                    yield splitter

            yield self._page(num_pages)
    
    
'''
{% if paginator and paginator.num_pages > 1 %}
<div class="m_pagination">
    <ul>
        <li><a href="?{{ paginator.first_page.url_params }}">В начало</a></li>
        <li><a href="?{{ paginator.prev_page.url_params }}" class="prev"></a></li>

        {% for page in paginator.page_xrange %}
            {% if page.is_splitter %}
                <li><span>{{ page.splitter }}</span></li>
            {% else %}
                {% if page.is_current %}
                    <li><a class="current" href="javascript:void(0);">{{ page.n }}</a></li>
                {% else %}
                    <li><a href="?{{ page.url_params }}">{{ page.n }}</a></li>
                {% endif %}
            {% endif %}
        {% endfor %}


        <li><a href="?{{ paginator.next_page.url_params }}" class="next"></a></li>
        <li><a href="?{{ paginator.last_page.url_params }}">В конец</a></li>
    </ul>
</div>
{% endif %}
'''