O Guia Definitivo do Yii 1.1

array(
'posts'=>'post/list',
'post/'=>'post/read',
'post//'=>'post/read',
)
• Calling $this->createUrl('post/list') generates /index.php/posts. The first rule is
applied.
• Calling $this->createUrl('post/read',array('id'=>100)) generates /index.php/post/100.
The second rule is applied.
• Calling $this->createUrl('post/read',array('year'=>2008,'title'=>'a sample post'))
generates /index.php/post/2008/a%20sample%20post. The third rule is applied.
• Calling $this->createUrl('post/read') generates /index.php/post/read. None of the rules
is applied.
In summary, when using createUrl to generate a URL, the route and the GET parameters
passed to the method are used to decide which URL rule to be applied. If every parameter
associated with a rule can be found in the GET parameters passed to createUrl, and if the
route of the rule also matches the route parameter, the rule will be used to generate the
URL.
If the GET parameters passed to createUrl are more than those required by a rule, the
additional parameters will appear in the query string. For example, if we call $this-
>createUrl('post/read',array('id'=>100,'year'=>2008)), we would obtain /index.php/post/
100?year=2008. In order to make these additional parameters appear in the path info part,
we should append /*to the rule. Therefore, with the rule post//*, we can obtain the
URL as/index.php/post/100/year/2008.
As we mentioned, the other purpose of URL rules is to parse the requesting URLs.
Naturally, this is an inverse process of URL creation. For example, when a user requests
for /index.php/post/100, the second rule in the above example will apply, which resolves in
the route post/read and the GET parameter array('id'=>100) (accessible via $_GET).
Note: Using URL rules will degrade application performance. This is because when
parsing the request URL, CUrlManager will attempt to match it with each rule until one
can be applied. The more the number of rules, the more the performance impact.
Therefore, a high-traffic Web application should minimize its use of URL rules.
Parameterizing Routes
Starting from version 1.0.5, we may reference named parameters in the route part of a
rule. This allows a rule to be applied to multiple routes based on matching criteria. It may
also help reduce the number of rules needed for an application, and thus improve the
overall performance.
We use the following example rules to illustrate how to parameterize routes with named
parameters: