Guide to installing Tesla and creating your models.

Installation

It is assumed that you have Python 5 installed on your machine, plus easy_install etc, and that you are familiar with Pylons, SQLAlchemy and Elixir.

1. Download the template.

There are two ways to do this:

easy_install [-U] Tesla

For the development version:

easy_install [-U] Tesla==dev

This should also install dependencies, if they are not already installed.

2. Check installation works.

paster create --list-templates

"tesla" and "tesla_auth" should be in the list.

Sample Tesla application

We'll create a very simple blogging tool, myblog, for our purposes. SQLite database will be used as it's the easiest to get up and running.

1. Create your project.

paster create myblog -t tesla

You should now have a Pylons app ready to go. Change to the myblog directory.

2. Edit database settings.

Open up development.ini and set the SQLAlchemy database URI accordingly :

sqlalchemy.default.uri = sqlite:///%{here}s/myblog_development.db

See here for how to set the SQLAlchemy URI for your database.

3. Create model files.

paster model posts

Two files should now be created: myblog/models/posts.py and myblog/tests/unit/test_posts.py.

4. Create a model class.

Open myblog/model/posts.py and create a simple Entity class:

from elixir import *

class BlogPost(Entity):
    has_field('title', Unicode(100), required = True)
    has_field('content', Unicode)
    using_options(tablename = 'posts')

The model class needs to be imported into myblog/model/__init__.py so it can be "seen" by the application. Add the following to the bottom of myblog/model/__init__.py:

from posts import BlogPost

Note: if you want to use the SQLAlchemy autoload feature (which uses reflection on the database schema rather than declaring your columns in code) then open up myblog/lib/database.py and uncomment these lines:

#if not metadata.is_bound():
#    elixir.delay_setup = True

5. Create the database tables.

paster create_sql development.ini [posts]

This will create all the database tables for the application if they don't exist yet. You can optionally pass in the name of a single table to be created.

6. Create a sample post.

Run paster shell development.ini. You can now type:

p = model.BlogPost(title = 'My first post', content = 'yippee!')
p.flush()

A blog post should now be in the database.

7. Set up your tests.

Tesla by default uses an in-memory SQLite database. You can change this in test.ini if needed.

Open up myblog/tests/unit/test_posts.py. You should see the following code:

from myblog.tests import *

class TestPosts(TestModel):
    pass

Let's add a simple test in here:

from myblog.tests import *

class TestPosts(TestModel):
    def test_create_post(self):
        post = model.BlogPost(name = 'a post', content='blah')
        post.flush()
        self.failUnlessEqual(model.BlogPost.count(), 1)        

Then run nosetests to see if the test passes.