Render Multiple Jinja Templates with One Handler

Question

Hello Stackoverflow Guru's!

I'm a complete newb, and I've got a question that I can't seem to find the answer to (hopefully because it's so simple nobody has bothered to ask).

I'm designing a website that has a bunch of recipes using google app engine. I'd like to be able to render a bunch of the recipe pages using one handler, because I plan of having lots of recipes later and I don't want to have to make a new handler for each one. My code is below:

import urllib2
import webapp2
import jinja2
import os


JINJA_ENVIRONMENT = jinja2.Environment(
loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
extensions=['jinja2.ext.autoescape'],
autoescape=True)

class Handler(webapp2.RequestHandler):
def write(self, *a, **kw):
    self.response.out.write(*a, **kw)

def render_str(self,template,**params):
    t = JINJA_ENVIRONMENT.get_template(template)
    return t.render(params)

def render(self,template,**kw):
    self.write(self.render_str(template,**kw))

class MainHandler(Handler):
def get(self):
    template = JINJA_ENVIRONMENT.get_template('main.html')
    self.response.write(template.render())

class RecipeHandler(Handler, recipe):
def get(self, recipe):
    recipe_pages = {
    'carbonara' : 'carbonara.html'
    'burger' : 'burger.html'
    }
    if recipe in recipe_pages:
        template = JINJA_ENVIRONMENT.get_template(recipe_pages[recipe])
        self.response.write(template.render())
    else:
        self.abort(404)



app = webapp2.WSGIApplication([
('/', MainHandler),
('/carbonara', RecipeHandler(carbonara)),
('/burger',RecipeHandler(burger)),
], debug=True)

I basically want to avoid writing out a "CarbonaraHander" and "BurgerHandler", and just use "RecipeHandler" to render both pages. I know this should be possible, but I have no idea how to do it.

Any help is appreciated!

Edit: I think I should be using something called regular expressions? But I don't really understand how they need to be used in this case.

Answer 1

AFAIK you can't pass args to the handler, you need to extract them from the request. This is what I'd do (pushed it a bit further to directly use the template name in the URl routing):

class RecipeHandler(Handler):

    def extract_template_name_from_request(self):

        return self.request.path_info[9:] # strip leading '/recipes/' (or whatever else you need)

    def get(self):

        template_name = self.extract_template_name_from_request()
        try:
            template = JINJA_ENVIRONMENT.get_template(template_name)
        except Exception:
            # can't locate a template matching the requested path
            self.abort(404)
            return

        # prepare the template values as needed
        values = {'recipe': {'name': template_name[:-5]}}  # just an example

        try:
            self.response.write(template.render(values))
        except Exception:
            # failure rendering the template
            self.abort(500)

app = webapp2.WSGIApplication([
    ('/recipes/.*.html', RecipeHandler), # see extract_template_name_from_request()
    ('/.*', MainHandler),
], debug=True)