base.py

"""The base Controller API

Provides the BaseController class for subclassing.
"""
from pylons.controllers import WSGIController
from pylons.templating import render_mako as render

from pylons import request, tmpl_context as c, response
from pylons.controllers.util import abort, redirect

from foo.model.meta import Session
from foo.model import User

from webhelpers.paginate import Page
from pprint import pformat

from sqlalchemy import asc, desc

import csv, re
from StringIO import StringIO
from datetime import date

class BaseController(WSGIController):

    def __call__(self, environ, start_response):
        """Invoke the Controller"""

        # WSGIController.__call__ dispatches to the Controller method
        # the request is routed to. This routing information is
        # available in environ['pylons.routes_dict']

        try:
            return WSGIController.__call__(self, environ, start_response)
        finally:
            Session.remove()

    def __dump__(self, data):
        response.content_type = 'text/plain'
        return pformat(data)

    def __get_user__(self):

        if not request.environ.get('app.user') and 'REMOTE_USER' in request.environ:
            request.environ['app.user'] = Session.query(User).filter_by(email=request.environ['REMOTE_USER']).first()

        return request.environ.get('app.user')

    __user__ = property(__get_user__)

    def __fetch__(self, model, **kwargs):
        '''
        Fetch a record from model or 404 as appropriate
        '''

        if id is None:
            abort(404)

        rv = Session.query(model).filter_by(**kwargs).one()
        if rv is None:
            abort(404)

        return rv

    def __export__(self, filename, seq):

        if request.GET.get('format') != 'csv':
            abort(400)

        rv = StringIO()

        writer = csv.writer(rv)
        writer.writerows(seq)

        ts = date.today().strftime('%Y-%m-%d')

        data = rv.getvalue()

        response.headers['Content-Type']        = 'text/csv'
        response.headers['Content-Length']      = len(data)
        response.headers['Content-Disposition'] = 'attachment; filename=%s-%s.csv;' % (re.sub(r'[^\w -]', '', filename), ts)
        response.headers['Cache-Control']       = 'maxage=1'
        response.headers['Pragma']              = 'public'

        return data
    
    def __filter__(self, query):
        return query

    def __paginate__(self, query, page=1, count=20, order=None, sort='asc'):

        if 'page' not in request.GET:
            request.GET['page'] = page

        if 'count' not in request.GET:
            request.GET['count'] = count

        if 'order' not in request.GET and order is not None:
            request.GET['order'] = order

        if 'sort' not in request.GET:
            request.GET['sort'] = sort

        if 'order' in request.GET:
            ordering  = request.GET['order'].lower()
            sort_func = desc if request.GET['sort'].lower() == 'desc' else asc

            if ordering in self.orderings:
                query = query.order_by(sort_func(self.orderings[ordering]))

        query = self.__filter__(query)

        rv = Page(query,
                  page           = int(request.GET['page']),
                  items_per_page = int(request.GET['count']))

        return rv