Difference between #2 and #1 of How to extend yiic shell commands

yiic

> Note: this tutorial requires Yii 1.0.8 or later.

While `yiic shell` tool is very convenient at generating skeleton code in our
application, the generated code is not always what we want. For example, we may
want the generated code to carry specific copyright information; we may want to
use our own coding style; we may want to add more features; and so on. All these
can be accomplished easily in Yii.

In the following, we explain how to extend the `model` and `crud` commands,
which are the two most powerful `yiic shell` commands.


## Extending `model` Command

When we create our initial application code using `yiic webapp` command, we may
find there is a directory called `protected/commands/shell`. This is the place
where we shall store the extended shell command classes. 

In order to extend the `model` command, we would write a class named
`MymodelCommand` and save it as the file `MymodelCommand.php` under
`protected/commands/shell`:

~~~
[php]
Yii::import('system.cli.commands.shell.ModelCommand');

defined('MY_MODEL_TEMPLATE') or
	define('MY_MODEL_TEMPLATE',dirname(__FILE__).'/templates/model');

class MymodelCommand extends ModelCommand
{
	public $templatePath=MY_MODEL_TEMPLATE;
}
~~~

Our new command class extends from `ModelCommand` which implements the default
behavior of the `model` command. The new command mainly overrides the
`templatePath` property which specifies where the template for generating new
model class files should be located. Here, we declare it to be the constant
`MY_MODEL_TEMPLATE` which represents the directory
`protected/commands/shell/templates/model`.

Next, we would like to provide our own version of the template. 
A template is a PHP script that is executed by a shell command. The rendering
result of this PHP script is the code generated by the corresponding shell
command.

The easiest way to create a new template is to modify the one used by the
default `model` command which is located at
`framework/cli/views/shell/model/model.php`. We should copy this file to
`protected/commands/shell/templates/model` and then modify it according to our
needs.

If we edit the template file, we should see the following comments at the
beginning. Read carefull since they list variables that can be used in the
template.

~~~
[php]
<?php
/**
 * This is the template for generating a model class file.
 * The following variables are available in this template:
 * - $className: the class name
 * - $tableName: the table name
 * - $columns: a list of table column schema objects
 * - $rules: a list of validation rules (string)
 * - $labels: a list of labels (column name => label)
 * - $relations: a  list of relations (string)
 */
......
?>
~~~

We should be able to use our newly created model command now. Enter the `yiic
shell` and type `help`. We should see a list of available shell commands which
now include a new command called `mymodel`. Try using this command the same way
as using the original `model` command (e.g. `mymodel Post`). We should see that
the generated model class is using the template we just wrote.


## Extending `crud` Command

Extending the `crud` command is only a bit more complex than extending the
`model` command. We create a file named
`protected/commands/shell/MycrudCommand.php` as follows,

~~~
[php]
Yii::import('system.cli.commands.shell.CrudCommand');

defined('MY_CRUD_TEMPLATE') or 
	define('MY_CRUD_TEMPLATE',dirname(__FILE__).'/templates/crud');

class MycrudCommand extends CrudCommand
{
	public $templatePath=MY_CRUD_TEMPLATE;
	public $actions=array('insert','update','list','view','_form');
}
~~~

In the above, we state that the new template directory should be
`protected/commands/shell/templates/crud` and we want to generate five CRUD
views: `insert`, `update`, `list`, `view` and `_form`. Note that the default
`crud` command generates six views: `create`, `update`, `list`, `view`, `admin`
and `_form`.

Next, we generate the needed templates for our new CRUD command. Like before, we
would copy the existing templates from `framework/cli/views/shell/crud` to
`protected/commands/shell/templates/crud` and then modify them. According to our
new `actions` property, we need to delete `admin.php` and rename `create.php` to
be `insert.php`.

After all these are completed, we may enter `yiic shell` and execute `mycrud
Post` to generate our customized CRUD code for the `Post` model class.