To get an initial experience with Yii, we describe in this section how to
create our first Yii application. We will use the powerful
which can be used to automate code creation for certain tasks. For convenience,
we assume that
YiiRoot is the directory where Yii is installed, and
is the document root of our Web server.
yiic on the command line as follows:
% YiiRoot/framework/yiic webapp WebRoot/testdrive
Note: When running
yiicon Mac OS, Linux or Unix, you may need to change the permission of the
yiicfile so that it is executable. Alternatively, you may run the tool as follows,% cd WebRoot/testdrive % php YiiRoot/framework/yiic.php webapp WebRoot/testdrive
This will create a skeleton Yii application under the directory
WebRoot/testdrive. The application has a directory structure that is
is needed by most Yii applications.
Without writing a single line of code, we can test drive our first Yii application by accessing the following URL in a Web browser:
As we can see, the application has three pages: the homepage, the contact page and the login page. The homepage shows some information about the application as well as the user login status, the contact page displays a contact form that users can fill in to submit their inquiries, and the login page allows users to be authenticated before accessing privileged contents. See the following screenshots for more details.
Contact page with input errors
Contact page with success
The following diagram shows the directory structure of our application. Please see Conventions for detailed explanation about this structure.
testdrive/ index.php Web application entry script file assets/ containing published resource files css/ containing CSS files images/ containing image files themes/ containing application themes protected/ containing protected application files yiic yiic command line script yiic.bat yiic command line script for Windows commands/ containing customized 'yiic' commands shell/ containing customized 'yiic shell' commands components/ containing reusable user components MainMenu.php the 'MainMenu' widget class Identity.php the 'Identity' class used for authentication views/ containing view files for widgets mainMenu.php the view file for 'MainMenu' widget config/ containing configuration files console.php the console application configuration main.php the Web application configuration controllers/ containing controller class files SiteController.php the default controller class extensions/ containing third-party extensions messages/ containing translated messages models/ containing model class files LoginForm.php the form model for 'login' action ContactForm.php the form model for 'contact' action runtime/ containing temporarily generated files views/ containing controller view and layout files layouts/ containing layout view files main.php the default layout for all views site/ containing view files for the 'site' controller contact.php the view for 'contact' action index.php the view for 'index' action login.php the view for 'login' action system/ containing system view files
Most Web applications are backed by databases. Our test-drive application
is not an exception. To use a database, we first need to tell the
application how to connect to it. This is done by changing the application
WebRoot/testdrive/protected/config/main.php, as shown
return array( ...... 'components'=>array( ...... 'db'=>array( 'connectionString'=>'sqlite:protected/data/source.db', ), ), ...... );
In the above, we add a
db entry to
components, which instructs the
application to connect to the SQLite database
WebRoot/testdrive/protected/data/source.db when needed.
Note: To use Yii's database feature, we need to enable PHP PDO extension and the driver-specific PDO extension. For the test-drive application, we would need the
php_pdo_sqliteextensions to be turned on.
To this end, we need to prepare a SQLite database so that the above configuration can be effective. Using some SQLite admin tool, we can create a database with the following schema:
CREATE TABLE User ( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, username VARCHAR(128) NOT NULL, password VARCHAR(128) NOT NULL, email VARCHAR(128) NOT NULL );
Note: If you are using MySQL database, you should replace
AUTO_INCREMENTin the above SQL.
For simplicity, we only create a single
User table in our database. The
SQLite database file is saved as
WebRoot/testdrive/protected/data/source.db. Note that both the file and the
containing directory must be made writable by the Web server process, as
required by SQLite.
Now is the fun part. We would like to implement the CRUD (create, read,
update and delete) operations for the
User table we just created. This is
also commonly needed in practical applications.
Instead of taking trouble to write actual code, we would use the powerful
yiic tool again to automatically generate the code for us. This
process is also known as scaffolding. Open a command line window, and execute
the commands listed as follows,
% cd WebRoot/testdrive % protected/yiic shell Yii Interactive Tool v1.0 Please type 'help' for help. Type 'exit' to quit. >> model User generate User.php The 'User' class has been successfully created in the following file: D:\wwwroot\testdrive\protected\models\User.php If you have a 'db' database connection, you can test it now with: $model=User::model()->find(); print_r($model); >> crud User generate UserController.php mkdir D:/wwwroot/testdrive/protected/views/user generate create.php generate update.php generate list.php generate show.php generate admin.php generate _form.php Crud 'user' has been successfully created. You may access it via: http://hostname/path/to/index.php?r=user
In the above, we use the
yiic shell command to interact with our
skeleton application. At the prompt, we execute two sub-commands:
crud User. The former generates a model class for the
while the latter reads the
User model and generates the code implementing
the CRUD operations.
Note: You may encounter errors like "...could not find driver", even though the requirement checker shows you have already enabled PDO and the corresponding PDO driver. If this happens, you may try to run the
yiictool as follows,% php -c path/to/php.ini protected/yiic.php shell
path/to/php.inirepresents the correct PHP ini file.
Let's enjoy our work by browsing the following URL:
This will display a list of user entries in the
User table. Since our
table is empty, nothing will appear at the moment.
New User link on the page. We will be brought to the login
page if we have not logged in before. After logged in, we are shown with
an input form that allows us to add a new user entry. Complete the form and
click on the
Create button. If there is any input error, a nice error
prompt will be shown which prevents us from saving the input. Back to the
user list, we should see the newly added user appearing in the list.
Repeat the above steps to add more users. Notice that user list page will automatically paginate the user entries if there are too many to be displayed in one page.
If we login as an administrator using
admin/admin, we can view the user
admin page with the following URL:
This will show us a nice table of user entries. We can click on the table header cells to sort the corresponding columns. And like the user list page, the admin page also performs pagination when there are too many user entries to be displayed in one page.
All these nice features come without requiring us to write a single line of code!
User admin page
Create new user page
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