One of the hidden features of the Yii URL router is that you can use regular expressions that are pretty powerful for handling strings.
- Create a new application using the Composer package manager, as described in the official guide at http://www.yiiframework.com/doc-2.0/guide-start-installation.html.
- In your
@app/controllersdirectory, createPostController.phpusing the following:<?php namespace appcontrollers; use yiihelpersHtml; use yiiwebController; class PostController extends Controller { public function actionView($alias) { return $this->renderContent(Html::tag('h2', 'Showing post with alias ' . Html::encode($alias) )); } public function actionIndex($type = 'posts', $order = 'DESC') { return $this->renderContent(Html::tag('h2', 'Showing ' . Html::encode($type) . ' ordered ' . Html::encode($order) )); } public function actionHello($name) { return $this->renderContent(Html::tag('h2', 'Hello, ' . Html::encode($name) . '!' )); } }This is our application controller that we are going to access using our custom URLs.
- Configure your application server to use clean URLs. If you are using Apache with
mod_rewriteandAllowOverrideturned on, then you should add the following lines to the.htaccessfile under your@webfolder:Options +FollowSymLinks IndexIgnore */* RewriteEngine on # if a directory or a file exists, use it directly RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d # otherwise forward it to index.php RewriteRule . index.php
We want our PostController action to accept parameters according to some specified rules and give the 404 not found HTTP response for all parameters that do not match. In addition, post/index should have an alias URL archive.
Add the following config of the urlManager component to @app/config/web.php:
'components' => [
// ..
'urlManager' => [
'enablePrettyUrl' => true,
'rules' => [
'post/<alias:[-a-z]+>' => 'post/view',
'<type:(archive|posts)>' => 'post/index',
'<type:(archive|posts)>/<order:(DESC|ASC)>' => 'post/index',
'sayhello/<name>' => 'post/hello',
]
],
// ..
],The following URLs will be successful:
http://yii-book.app/post/testhttp://yii-book.app/postshttp://yii-book.app/archivehttp://yii-book.app/posts/ASChttp://yii-book.app/sayhello
The following URLs will fail:
http://yii-book.app/archive/testhttp://yii-book.app/post/another_post
The following screenshot shows that the URL http://yii-book.app/post/test has run successfully:
The following screenshot shows that the URL http://yii-book.app/archive has run successfully too:
The following screenshot shows that the URL http://yii-book.app/archive/test did not run successfully and encountered an error:
You can use regular expressions in both the parameter definition and the rest of the rule. Let's read our rules one by one:
'post/<alias:[-a-z]+>' => 'post/view',
The alias parameter should contain one or more English letters or a dash. No other symbols are allowed.
'posts' => 'post/index', 'posts/' => 'post/index',
Both paths lead to post/index. The order parameter can only accept two values — DESC and ASC.
'sayhello/' => 'post/hello',
You should specify the name part but there are no restrictions on what characters are allowed. Note that regardless of the rule used, the developer should never assume that the input data is safe.
To learn more about regular expressions, you can use the following sources:
- http://www.php.net/manual/en/reference.pcre.pattern.syntax.php
- Mastering Regular Expressions, Jeffrey Friedl available at http://regex.info/.