| Status: | Work in progress |
|---|
Table of Contents
We assume that you have TurboGears installed and, if you installed it in a virtual environment as recommended, that your virtualenv is activated. See TurboGears 2.1.5 Standard Installation to get to this point.
TurboGears 2 extends the paster command-line tool to provide a
suite of tools for working with TurboGears 2 projects. A few will be
touched upon in this tutorial, check the paster --help command for
a full listing.
The very first tool you’ll need is paster quickstart, which
initializes a TurboGears 2 project. You can go to whatever directory
you want and start a new TurboGears 2 project.
$ paster quickstart
The paster quickstart command will create a basic project
directory for you to use to get started on your TurboGears 2
application. You’ll be prompted for the name of the project (this is
the pretty name that human beings would appreciate), and the name of
the package (this is the less-pretty name that Python will like).
Here’s what our choices for this tutorial look like:
Enter project name: Helloworld
Enter package name [helloworld]: helloworld
Do you need authentication and authorization in this project? [yes]
...output...
This will create a new directory which contains a few files in a directory tree, with some code already set up for you.
Note
Passing --minimal to the paster quickstart command will
create an empty project with only the RootController.
While this is not reccomended for new users it might speed up the
process of starting a new project for expert users.
Let’s go in there and you can take a look around.
$ cd Helloworld
The setup.py file has a section which explicitly declares the
dependencies of your application. The quickstart template has a few
built in dependencies, and as you add new python libraries to your
application’s stack, you’ll want to add them here too.
Then in order to make sure all those dependencies are installed you will want to run.
$ python setup.py develop
If you have just installed TurboGears and are in a relatively new virtualenv, expect to see a bit of output about additional packages being installed.
Most applications will use a database, and since we specified we are using “authentication” in our quickstart, we need a place to store users and permissions. Before you run your application for the first time, you need to make sure the database is created and initialized. The following command typically only needs to be run once.
$ paster setup-app development.ini
With the quickstart command from above, you will see quite a bit of output which shows you the SQL commands that create the authentication tables and setup a default user/password for you:
user: manager
password: managepass
You don’t need to understand all of this now, but here is a little background about how “paster setup-app” knows what to do. By default, the database is created using SQLite, and the data is stored in a file, devdata.db, in the top level of your project. The information about what database driver is used is specified in the development.ini file passed on the command line. The code which adds the initial data rows is in helloword/web_setup.py. The command “paster setup-app” ends up calling the function “setup_app” within this file.
Another key piece of TG2 application setup infrastructure is the
paster setup-app command which takes a configuration file and runs
your project’s websetup code in that context. This allows you to use
setup-app to create database tables, pre-populate require data into
your database, and otherwise make things nice for people first setting
up your app. If you take a look at your project’s quickstart, you
will see a websetup Python script. Inside of this script, you will see
a single functon, setup_app, that is called when paster setup-app
is run. Inside of this, you may do any setup you need to for your
application. The most common operations will be to add in basic data
to the database that is required to bootstrap your application.
Note
If it’s the first time you’re going to use the application,
and you told quickstart to include authentication+authorizaiton, you
will have to run setup-app to set it up (e.g., create a test
database).
$ paster setup-app development.ini
This will create the database using the information stored in the development.ini file which by default makes single file SQLite database in the local file system. In addition to creating the database, it runs whatever extra database loaders or other setup are defined in {yourproject}.websetup:setup_app.
In a quickstarted project with Authorization enabled setup-app creates a couple of basic users, groups, and permissions for you to use as an example. This code is found in {yourproject}.websetup:setup_app. This code also shows how you can add new data automatically to the database when the setup-app command is executed..
At this point your project should be operational, and you’re ready to
start up the app. To start a TurboGears 2 app, you need to be in the
top level of your project directory (Helloworld) and issue the
command paster serve to serve your new application.
$ paster serve development.ini
As soon as that’s done point your browser at http://localhost:8080/ and you’ll see a nice welcome page.
Note
If you’re exploring TurboGears 2 after using TurboGears 1 you may notice a few things:
paster serve command is not in auto-reload mode as
the CherryPy server used to be. If you also want your application to
auto-reload whenever you change a source code file just add the
--reload option to paster serve:$ paster serve --reload development.ini
You might also notice that paster serve can be run from any directory as long as you give it the path to the right ini file.
In order to run the server in development mode, where your Python files are reloaded automatically when they are changed, you typically use the following command.
paster serve --reload development.ini
If you take a look at the code that quickstart created you’ll see that there isn’t much involved in getting up and running. In particular, you’ll want to check out the files directly involved in displaying this welcome page:
You can easily edit development.ini to change the default server port used by the built-in web server:
[server:main]
...
port = 8080
Just change 8080 to 80, and you’ll be serving your app up on a standard port (assuming your OS allows you to do this using your normal account).
You might also wish to have paster listening on all IP addresses on your machine. To do so, modify the line right above the port line (in development.ini) to have the value 0.0.0.0, like so:
[server:main]
...
host = 0.0.0.0
TurboGears supports MongoDB out of the box by using the Ming ORM. Ming was made to look like SQLAlchemy, so if you are proficient with SQLAlchemy and MongoDB it should be easy for you to get used to the Ming query language. This also makes easy to port a TurboGears SQLAlchemy based application to MongoDB.
To create a project using MongoDB you just need to pass the --ming
option to the paster quickstart command.
$ paster quickstart --ming
The quickstarted project will provide an authentication and authorization layer like the one that is provided for the SQLAlchemy version. This means that you will have the same users and groups you had on the standard quickstarted project and also that all the predicates to check for authorization should work like before.
The main difference is that you won’t be able to use the application without having a running MongoDB database on the local machine.
By default the application will try to connect to a server on port 27017 on local machine using a database that has the same name of your package.
This can be changed by editing the development.ini file:
ming.url = mongodb://localhost:27017/
ming.db = myproject
Now that everything is in place to start using MongoDB as your database server you just need to proceed the usual way by filling your database.
$ paster setup-app development.ini
The quickstart command from above will create the authentication collections and setup a default user/password for you:
user: manager
password: managepass
For more informations about Ming and MongoDB support please refer to the Working With Ming And MongoDB section.