Source code for fantastico.mvc.base_controller

'''
Copyright 2013 Cosnita Radu Viorel

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
documentation files (the "Software"), to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

.. codeauthor:: Radu Viorel Cosnita <radu.cosnita@gmail.com>

.. py:module:: fantastico.mvc.base_controller
'''
from fantastico.exceptions import FantasticoTemplateNotFoundError, FantasticoError
from fantastico.utils import instantiator
from jinja2.environment import Environment
from jinja2.exceptions import TemplateNotFound
from jinja2.loaders import FileSystemLoader
import os
from fantastico.settings import BasicSettings

class BaseController(object):
    '''This class provides common methods useful for every concrete controller. Even if no type checking is done in
    Fantastico it is recommended that every controller implementation inherits this class.'''

    def __init__(self, settings_facade):
        self._settings_facade = settings_facade

        self._tpl_loader = None
        self._tpl_env = None
        self._curr_request = None

    @property
    def curr_request(self):
        '''This property returns the current http request being processed.'''

        return self._curr_request

    @curr_request.setter
    def curr_request(self, curr_request):
        '''This method sets the current request being processed by this controller.'''

        self._curr_request = curr_request

        if self._tpl_env:
            self._tpl_env.fantastico_request = self._curr_request

    def __init_jinja_context(self):
        '''This method initialize the jinja context in order to make the controller able to render jinja2 files.'''

        views_folder = ("%s%s/views/" % (self._settings_facade.get_root_folder(), self.get_component_folder()))

        self._tpl_loader = FileSystemLoader(searchpath=views_folder)
        self._tpl_env = Environment(loader=self._tpl_loader, **self._settings_facade.get("templates_config"))
        self._tpl_env.fantastico_request = self._curr_request

    def get_component_folder(self):
        '''This method is used to retrieve the component folder name under which this controller is defined.'''

        root_folder = self._settings_facade.get_root_folder()

        return instantiator.get_component_path_data(self.__class__, root_folder)[0]

    def load_template(self, tpl_name, model_data=None, get_template=Environment.get_template, enable_global_folder=False):
        '''This method is responsible for loading a template from disk and render it using the given model data.

        .. code-block:: python

            @ControllerProvider()
            class TestController(BaseController):
                @Controller(url="/simple/test/hello", method="GET")
                def say_hello(self, request):
                    return Response(self.load_template("/hello.html"))

        The above snippet will search for **hello.html** into component folder/views/.
        '''

        if self._tpl_env is None:
            self.__init_jinja_context()

        model_data = model_data or {}

        if enable_global_folder:
            config_cls = self._settings_facade.get_config().__class__
            parent_path = instantiator.get_class_abslocation(config_cls)

            if config_cls != BasicSettings:
                parent_path = os.path.abspath("%s../" % parent_path)

            if parent_path not in self._tpl_loader.searchpath:
                self._tpl_loader.searchpath.append(parent_path)

        try:
            return get_template(self._tpl_env, tpl_name).render(model_data)
        except TemplateNotFound as ex:
            raise FantasticoTemplateNotFoundError(ex)
        except Exception as ex:
            raise FantasticoError(ex)