观察者：包含的观察者
下列是包含的观察者：
Observer_Self
While not exactly good practice, in some cases it's probably cleanest to just have the event method with your model. That's where the Observer_Self comes in, it checks if you model has a method named after the event and prefixed with _event_. For example for the after_save event you need to add a public method _event_after_save() to your model so it can have the observer call on the model itself.
// 只添加观察者
protected static $_observers = array('Orm\\Observer_Self');
// But if you only observe some events you can optimize by only adding those
protected static $_observers = array('Orm\\Observer_Self' => array(
'events' => array('after_save', 'before_insert')
));Observer_CreatedAt
This observer acts only upon before_insert and expects your model to have a created_at property which will be set to the Unix timestamp when saving for the first time.
// 只添加观察者
protected static $_observers = array('Orm\\Observer_CreatedAt');
// Adding it with config:
// - only needs to run on before_insert
// - use mysql timestamp (uses UNIX timestamp by default)
// - use just "created" instead of "created_at"
protected static $_observers = array(
'Orm\\Observer_CreatedAt' => array(
'events' => array('before_insert'),
'mysql_timestamp' => true,
'property' => 'created',
'overwrite' => true,
),
);If you want to be able to set the created_at timestamp in your code, set the 'overwrite' property to false. This will cause the observer to keep the value you have set manually.
Observer_UpdatedAt
This observer acts only upon before_save or before_update and expects your model to have a updated_at property which will be set to the Unix timestamp when saving (also during the first time).
当你使用 before_save，updatedAt 行在 insert 和 update 时都会被更新。 当你使用 before_update，updatedAt 行只在 update 时会被更新。
// 别使用它，这会让它执行两次！
protected static $_observers = array('Orm\\Observer_UpdatedAt');
// Adding it with config:
// - only needs to run on before_save
// - use mysql timestamp (uses UNIX timestamp by default)
// - use just "updated" instead of "updated_at"
protected static $_observers = array(
'Orm\\Observer_UpdatedAt' => array(
'events' => array('before_save'),
'mysql_timestamp' => true,
'property' => 'updated',
'relations' => array(
'my_relation',
),
),
);By default the timestamp will not be updated if a child object has changed. This behaviour can be changed by adding the names of the relations to the optional relations property.
For example, if you have a Model_Blog that has many Model_Posts, with the slug observer applied to the blog, then update a post through the blog's relations the blog's updated_at will not be triggered.
$blog->post[0]->title = 'foobar';
$blog->save();
With the post relation specified in the relations property the updated at observer will update the timestamp in the blog if the post is edited.
If a relation is not loaded then it will be ignored by the updated at observer.
Observer_Validation
This observer can act on before_insert and/or before_update, or on before_save. Do not use both before_save and one of the others, that would cause your rules to be called twice. It is used to prevent the model from saving if validation rules fail. It uses the Fieldset class and can also generate the form for you.
The primary key(s) are not added to Validation nor to the Form as they're not editable and will be auto-increment most of the time. In cases where you set it upon creation and need validation you'll need to add the field manually.
The observer can be loaded as follows:
// 只添加观察者，并定义需要的事件
protected static $_observers = array('Orm\\Observer_Validation' => array(
'events' => array('before_save')
));不要定义该观察者而没带事件类型，因为这会导致它被呼叫两次！
Validation rules should be defined in your model in $_properties. This is demonstrated in Creating Models. After you have added the Validation Observer, the Orm\ValidationFailed exception will be thrown when the model's data fails to validate before save. As such, you must try/catch your calls to the save function of a model.
More extensive example functionality/scaffolding is shown below:
class Controller_Articles extends Controller
{
public function action_create()
{
$view = View::forge('articles/create');
if (Input::param() != array())
{
try
{
$article = Model_Article::forge();
$article->name = Input::param('name');
$article->url = Input::param('url');
$article->save();
Response::redirect('articles');
}
catch (Orm\ValidationFailed $e)
{
$view->set('errors', $e->getMessage(), false);
}
}
return Response::forge($view);
}
public function action_edit($id = false)
{
if ( ! ($article = Model_Article::find($id))
{
throw new HttpNotFoundException();
}
$view = View::forge('articles/edit');
if (Input::param() != array())
{
try
{
$article->name = Input::param('name');
$article->url = Input::param('url');
$article->save();
Response::redirect('articles');
}
catch (Orm\ValidationFailed $e)
{
$view->set('errors', $e->getMessage(), false);
}
}
return Response::forge($view);
}
public function action_delete($id = null)
{
if ( ! ($article = Model_Article::find($id))
{
throw new HttpNotFoundException();
}
else
{
$article->delete();
}
Response::redirect('articles');
}
}By default, the HTML representation is passed as message to the ValidationFailed exception object, ready for display in your view. There are however cases where you would like to have access to the individual error messages, for example because you're in a RESTful API call, and you want to return the messages as JSON:
class Controller_Articles extends Controller_Rest
{
public function action_create()
{
$view = View::forge('articles/create');
if (Input::param() != array())
{
try
{
$article = Model_Article::forge();
$article->name = Input::param('name');
$article->url = Input::param('url');
$article->save();
Response::redirect('articles');
}
catch (Orm\ValidationFailed $e)
{
$errors = array();
foreach ($e->get_fieldset()->validation()->error() as $error)
{
$errors = array(
'field' => $error->field, // the field that caused the error
'value' => $error->value, // the value that is in error
'message' => trim($error->get_message(false, '\t', '\t')), // the error message
'rule' => $error->rule, // the rule that failed
'params' => $error->params, // any parameters passed to the rule
);
}
return $errors;
}
}
return Response::forge($view);
}
}As this uses the Fieldset class to perform validation, it can also create forms for a model. In the following example, the create and edit forms are defined in a common view however you can just as easily define it in the model and obtain an instance of it in the view using Fieldset::instance().
// use an instance of Model_Article to create the form, you can also pass the classname
$fieldset = Fieldset::forge()->add_model($article);
// Populate the form with values from the model instance
// passing true will also make it use POST/PUT to repopulate after failed save
$fieldset->populate($article, true);
// The fieldset will be build as HTML when cast to string
echo $fieldset;Observer_Typing
This is for 2 things: type enforcement for input and type casting for output from the DB. That means that when you're saving the Typing observer will try to cast the input value to the expected type and throw an exception when it can't. And when you're retrieving DB data, normally it would all be strings (even integers and floats) but with the typing observer those will be cast to their scalar type.
In addition to the above the Typing observer also adds support for serialized & json fields. Both should be string type fields ("text" preferably) but will have their value encoded for saving (using serialize() or json_encode()) and decoded when retrieving from the DB (using unserialize() or json_decode()).
The Observer_Typing isn't meant as an alternative to validation, don't try to use it as such. Neither are the exceptions thrown by this observer meant to be read by the visitor of your site, they're meant to help you debug your code.
// 只添加观察者
protected static $_observers = array('Orm\\Observer_Typing');
// But adding it just for these specific events is enough
protected static $_observers = array('Orm\\Observer_Typing' => array(
'events' => array('before_save', 'after_save', 'after_load')
));For this observer to work you must have your the $_properties static variable set in your model, or not set at all using detection with DB::list_columns() (MySQL only!). When configuring it yourself the following settings are available:
| 变数 | 有效输入 | 描述 |
|---|---|---|
| data_type | varchar、int、integer、tinyint、smallint、mediumint、bigint、float、double、decimal[:d]、 text、tinytext、mediumtext、longtext、enum、set、bool、boolean、serialize、json、 time_unix、time_mysql | The SQL data type, Required to have the typing observer used on a field. |
| null | 布林 | Whether null is allowed as a value, default true |
| character_maximum_length | 整数 | The maximum number of characters allowed for a string data type (varchar, text) |
| min | 整数 | 整数的最小值 |
| max | 整数 | 整数的最大值 |
| options | 阵列 | Array of valid string values for set or enum data type Note: currently the options themselves cannot contain comma's. |
In case of data_type "decimal", you can suffix the type with the number of decimals required. If defined, the value returned is a string, formatted with the defined number of decimal digits, and taking the current defined locale into account.
Observer_Slug
This observer creates a url safe slug (unique by default) for your model. It works only upon before_insert and expects your model to have a title (to create the slug) and a slug (to save it) property.
// 只添加观察者
protected static $_observers = array('Orm\\Observer_Slug');
// 带设定
protected static $_observers = array(
'Orm\\Observer_Slug' => array(
'events' => array('before_insert'),
'source' => 'title', // property used to base the slug on, may also be array of properties
'property' => 'slug', // property to set the slug on when empty
'separator' => '-', // property to set the separator
'unique' => true, // property to require uniqueness or not
),
);
protected static $_observers = array('Orm\\Observer_Slug' => array('before_insert'));The Observer creates the slug from the title using Inflector::friendly_title() and adds an index, if the slug already exists.
In case of the overwrite property is false, you can assign a slug manually, which won't be overwritten by the Observer. Upon before_update the slug gets overwritten with the generated one from the title field (no matter overwrite property is false or not), but only in case the slug itself is not changed.