Документация по Yii 2 Framework

echo \Yii::$app->urlManager->createUrl(['site/page', 'id' => 'about']);
// /index.php/site/page/id/about/
echo \Yii::$app->urlManager->createUrl(['date-time/fast-forward', 'id' => 105])
// /index.php?r=date-time/fast-forward&id=105
echo \Yii::$app->urlManager->createAbsoluteUrl('blog/post/index');
// http://www.example.com/index.php/blog/post/index/

<?php
return [
    // ...
    'components' => [
        'urlManager' => [
            'enablePrettyUrl' => true,
            'showScriptName' => false,
            'enableStrictParsing' => true,
            'suffix' => '.html',
            'rules' => [
                '<action:(login|logout|about)>' => 'site/<action>',
 
                // ...
 
                ['class' => 'app\components\CarUrlRule', 'connectionID' => 'db', ...],
            ],  
        ],
    ],
];

echo Url::toRoute([''], $schema = false); // currently active route
echo Url::toRoute(['view', 'id' => 'contact'], $schema = false); // same controller, different action
echo Url::toRoute(['post/index'], $schema = false); // same module, different controller and action
echo Url::toRoute(['/site/index'], $schema = false); // absolute route no matter what controller is making this call
echo Url::toRoute(['post/read', 'id' => 100, '#' => 'title'], $schema = false)

echo Url::toRoute('', $schema = false); // currently active route
echo Url::toRoute('post/index', $schema = false); // same module, different controller and action
echo Url::toRoute('/site/index', $schema = false); // absolute route no matter what controller is making this call

echo Url::to('', $schema = false); // currently active route
echo Url::to('post/index', $schema = false); // same module, different controller and action
echo Url::to('/site/index', $schema = false); // absolute route no matter what controller is making this call

echo Url::to('@web', $schema = false);
echo Url::canonical(); // get canonical URL for the curent page
echo Url::home(); // get home URL
echo Url::remember(); // save URL to be used later
echo Url::previous(); // get previously saved URL

• $schema = true - Абсолютный адрес
• $schema = 'https' - Указание на испоользование шифрованного протокола

Синоним для yii\helpers\Url::toRoute

echo Url::to([''], $schema = false); // currently active route
echo Url::to(['view', 'id' => 'contact'], $schema = false); // same controller, different action
echo Url::to(['post/index'], $schema = false); // same module, different controller and action
echo Url::to(['/site/index'], $schema = false); // absolute route no matter what controller is making this call
echo Url::to(['post/read', 'id' => 100, '#' => 'title'], $schema = false)

Примеры использоватия можно глянуть в тестах https://github.com/yiisoft/yii2/blob/master/tests/unit/framework/helpers/UrlTest.php

echo Html::url(['']); // currently active route
echo Html::url(['view', 'id' => 'contact']); // same controller, different action
echo Html::url(['post/index']); // same module, different controller and action
echo Html::url(['/site/index']); // absolute route no matter what controller is making this call
echo Html::url(['post/read', 'id' => 100, '#' => 'title'])

echo Html::url(''); // currently active route
echo Html::url('post/index'); // same module, different controller and action
echo Html::url('/site/index'); // absolute route no matter what controller is making this call

вместо старых методов нада использовать yii\helpers\Url::to

Примеры использоватия можно глянуть в тестах https://github.com/yiisoft/yii2/blob/master/tests/unit/framework/helpers/UrlTest.php

echo $this->createUrl([''], $schema = null); // currently active route
echo $this->createUrl(['view', 'id' => 'contact'], $schema = null); // same controller, different action
echo $this->createUrl(['post/index'], $schema = null); // same module, different controller and action
echo $this->createUrl(['/site/index'], $schema = null); // absolute route no matter what controller is making this call
echo $this->createUrl(['post/read', 'id' => 100, '#' => 'title'], $schema = null)

echo $this->createUrl('', $schema = null); // currently active route
echo $this->createUrl('post/index', $schema = null); // same module, different controller and action
echo $this->createUrl('/site/index', $schema = null); // absolute route no matter what controller is making this call

Усли $this - это yii\web\Controller

echo $this->createAbsoluteUrl([''], $schema = null); // currently active route
echo $this->createAbsoluteUrl(['view', 'id' => 'contact'], $schema = null); // same controller, different action
echo $this->createAbsoluteUrl(['post/index'], $schema = null); // same module, different controller and action
echo $this->createAbsoluteUrl(['/site/index'], $schema = null); // absolute route no matter what controller is making this call
echo $this->createAbsoluteUrl(['post/read', 'id' => 100, '#' => 'title'], $schema = null)

вместо старых методов надо использовать yii\helpers::toRoute

Усли $this - это yii\web\Controller

echo $this->createAbsoluteUrl('', $schema = null); // currently active route
echo $this->createAbsoluteUrl('post/index', $schema = null); // same module, different controller and action
echo $this->createAbsoluteUrl('/site/index', $schema = null); // absolute route no matter what controller is making this call

вместо старых методов надо использовать yii\helpers::toRoute

Yii::$app->request->get();
Yii::$app->request->getQueryParams();
Yii::$app->request->getQueryParam('File');
Yii::$app->request->get('File');

Yii::$app->request->post();
Yii::$app->request->getBodyParams();
Yii::$app->request->getBodyParam('File');
Yii::$app->request->post('File');

$this->registerCssFile();

$this->registerJsFile();

В примере производится вставка JS кода из assets c применением переменной в скрипте JS_FABRIC_CAR_URL

$this = Yii::$app->view;

<?php 
$this->registerJs('var JS_FABRIC_CAR_URL = "' . Html::url(['/core/ajax/fabric-car']) . '";', View::POS_HEAD, 'js-fabric-car-url');
$publish = Yii::$app->assetManager->publish(Yii::getAlias('@app/modules/core/assets/js'));
$this->registerJsFile($publish[1] . '/block-select-car.js', [yii\web\JqueryAsset::className()], ['position'=>View::POS_END]);
?> 

'components' => [
    'assetManager' => [
        'class' => 'yii\web\AssetManager',
        'forceCopy' => true,          
    ],
],

• forceCopy - Включает постоянное обновление асетов

Добавление csrfToken в Ajax запрос (Yii2)

$js_global_variables = '
$.ajaxSetup({
        data: ' . \yii\helpers\Json::encode([
            \yii::$app->request->csrfParam => \yii::$app->request->csrfToken,
        ]) . '
    });' . PHP_EOL;
$this->registerJs($js_global_variables, yii\web\View::POS_HEAD, 'js_global_variables');

или через header

$js_global_variables = '
$.ajaxPrefilter(function( options ) {
    if ( !options.beforeSend) {
        options.beforeSend = function (xhr) { 
            xhr.setRequestHeader("HTTP_X_CSRF_TOKEN", ' . \yii::$app->request->csrfToken .');
        }
    }
});' . PHP_EOL;
$this->registerJs($js_global_variables, yii\web\View::POS_HEAD, 'js_global_variables');

или через JQuery

      $.ajax({
        url: 'http://site?controller/action',
        type: 'post',
        data: {payload: payload, _csrf: yii.getCsrfToken()},        
        dataType: 'json',
      }).success(function(response) {
      });