Yii v2 snippet guide

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  1. Intro
  2. Prerequisities
  3. Yii demo app + GitLab
  4. User management + DB creation + login via DB
  5. i18n translations
  6. Switching languages + session + dropdown in the top menu
  7. Access rights

Intro

Hi all!

This snippet guide continues in my series of simple Yii tutorials. Previous two contain basic info about MVC concept so read them as well, but they are meant for Yii v1. I started with them cca 8 years ago:

... and today I am beginning with Yii 2 so I will also gather my snippets and publish them here so we all can quickly setup the yii-basic-demo just by copying and pasting. This is my goal - to show how-to without long descriptions.

... technologies should not require users to study them deeply in order to run basic functionalities. Ordinary things should be copied and pasted so that one is happy that it works and thus motivated to study more ...

I have 4 years of experiences with Yii 1, but I havent used it for almost 5 years so many things in Yii 2 are new for me again. Plus I was suprised that the Yii 2 demo application does not contain some basic functionalities (like login via DB, translations etc) which must be implemented in the most of web projects so I will focus on them. Plus I will talk about GitLab.

If you find any problems in my snippets, let me know, please.

Prerequisities

Skip this paragraph if you know how to run your Yii demo project...

I work with Win10 + XAMPP Server so I will expect this configuration. Do not forget to start the server and enable Apache + MySQL in the dialog. Then test that following 2 URLs work for you

You should also download the Yii basic demo application and place it into the htdocs folder. In my case it is here:

  • C:\xampp\htdocs

And your index.php should be here:

  • C:\xampp\htdocs\basic\web\index.php

If you set thing correcly up, following URL will open your demo application. Now it will probably throw an exception:

The Exception is removed by enterinng any text into attribute 'cookieValidationKey' in file:

  • C:\xampp\htdocs\basic\config\web.php

Dont forget to connect Yii to the DB. It is done in file:

  • C:\xampp\htdocs\basic\config\db.php

... but it should work out-of-the-box if you use DB name "yii2basic" which is also used in examples below ...

Yii demo app + GitLab

Once I know more about GitLab I will add some info ... for example automatical copying from GitLab to your target web space.

Once you download and run the basic app, I recommend to push it into GitLab. You will probably need a SSH certificate which can be generated like this using PuTTYgen. When I work with Git I use TortoiseGIT which integrates all git functionalities into the context menu in Windows File Explorer.

First go to GitLab web and create a new project. Then you might need to fight a bit, because the process of connecting your PC to GIT seems to be quite complicated. At least for me.

Once things work, just create an empty folder, right click it and select Git Clone. Enter your git path, best is this format:

When cloned, copy the content of the "basic" folder into the new empty git-folder and push everything except for folder "vendor". (It contains 75MB and 7000 files so you dont want to have it in GIT)

Then you can start to modify you project, for example based on this "tutorial".

User management + DB creation + login via DB

To create DB with users, use following command. I recommend charset utf8_unicode_ci (or utf8mb4_unicode_ci) as it allows you to use more international characters.

CREATE DATABASE IF NOT EXISTS `yii2basic` DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;

CREATE TABLE IF NOT EXISTS `user` (
  `id` INT NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(45) NOT NULL,
  `password` VARCHAR(60) NOT NULL,
  `email`    VARCHAR(60) NOT NULL,
  `authKey`  VARCHAR(60),
  PRIMARY KEY (`id`))
ENGINE = InnoDB;

INSERT INTO `user` (`id`, `username`, `password`, `email`, `authKey`) VALUES (NULL, 'user01', '0497fe4d674fe37194a6fcb08913e596ef6a307f', 'user01@gmail.com', NULL);

If you must use MyISAM instead of InnoDB, just change the word InnoDB into MYISAM.

Then use GII to generate model. The GII URL will probably be

  • http://localhost/basic/web/index.php?r=gii.
  • When creating the model, check this checkbox: Enable I18N ... we will need i18n later
  • Enter table name "user" and model name "User"
  • Do not create CRUD now, first replace the new User model with the code below.

  • Note that there already is a model named User in the demo app. You will not need it if you want to use login-via-DB so feel free to check the overwrite-checkbox in GII. The newly created User model will now be usable only for table operations, not for login. But we will enhance it, see te snippet below.
  • The new model will only have 3 methods: tableName(), rules(), attributeLabels()
  • In order to use the DB for login, we need to implement IdentityInterface which requires 5 new methods. But as I do not need all those methods, in some of them I have commented out their body in the example below.
  • Plus we add 2 methods because of the default LoginForm

The final model should look like this:

<?php

namespace app\models;

use Yii;

class User extends \yii\db\ActiveRecord implements \yii\web\IdentityInterface {

    // When user detail is being edited we will only modify attribute password_new
    // Why? We dont want to load password-hash from DB and display it to the user
    // We only want him to see empty field and if it is filled in, password is changed on background
    public $password_new;
    public $password_new_repeat;

    // Use this scenario in UserController->actionCreate() right after: $model = new User() like this:
    // $model->scenario = User::SCENARIO_CREATE;
    // This will force the user to enter the password when new user is created
    // When user is edited, new password is not needed
    const SCENARIO_CREATE = "user-create";

    // ----- Default 3 model-methods by GII:

    public static function tableName() {
        return 'user';
    }

    public function rules() {
        return [
            [['username', 'email'], 'required'],
            [['password_new_repeat', 'password_new'], 'required', "on" => self::SCENARIO_CREATE],
            [['username', 'email'], 'string', 'max' => 45],
            ['email', 'email'],
            [['password', 'authKey'], 'string', 'max' => 60],
            [['password', 'password_new_repeat', 'password_new'], 'safe'],
            ['password_new_repeat', 'compare', 'operator' => '==', 'compareAttribute' => 'password_new'],
            ['password_new_repeat', 'setPasswordWhenChanged'],
        ];
    }

    public function attributeLabels() {
        return [
            'id' => Yii::t('app', 'ID'),
            'username' => Yii::t('app', 'Username'),
            'password' => Yii::t('app', 'Password'),
            'password_new' => Yii::t('app', 'New password'),
            'password_new_repeat' => Yii::t('app', 'Repeat new password'),
            'authKey' => Yii::t('app', 'Auth Key'),
            'email' => Yii::t('app', 'Email'),
        ];
    }

    // ----- Password validator

    public function setPasswordWhenChanged($attribute_name, $params) {

        if (trim($this->password_new_repeat) === "") {
            return true;
        }

        if ($this->password_new_repeat === $this->password_new) {
            $this->password = sha1($this->password_new_repeat);
        }

        return true;
    }

    // ----- IdentityInterface methods:

    public static function findIdentity($id) {
        return static::findOne($id);
    }

    public static function findIdentityByAccessToken($token, $type = null) {
        return static::findOne(['access_token' => $token]);
    }

    public function getId() {
        return $this->id;
    }

    public function getAuthKey() {
        return $this->authKey;
    }

    public function validateAuthKey($authKey) {
        return $this->authKey === $authKey;
    }

    // ----- Because of default LoginForm:

    public static function findByUsername($username) {
        return static::findOne(['username' => $username]);
    }

    public function validatePassword($password) {
        return $this->password === sha1($password);
    }

}

Now you can also create CRUD = Create Read Update Delete = views and controller. On the GII page enter following values:

  • Model Class = app\models\User
  • Search Model Class = app\models\UserSearch
  • Controller Class = app\controllers\UserController
  • View Path can be empty or you can set: views\user
  • Again enable i18n

And then you can edit users on this URL: http://localhost/basic/web/index.php?r=user ... but it is not all. You have to modify the view-files so that correct input fields are displayed!

Open folder views\user and do following:

  • _form.php - rename input password to password_new then duplicate it and rename to password_new_repeat. Remove authKey.
  • _search.php - remove password and authKey.
  • index.php - remove password and authKey.
  • view.php - remove password and authKey.

Plus do not forget to use the new scenario in UserController->actionCreate() like this:

public function actionCreate()
{
  $model = new User();
  $model->scenario = User::SCENARIO_CREATE; // the new scenario!
  // ...

i18n translations

Translations are fairly simple, but I probably didnt read manuals carefully so it took me some time.

First create following folders and file.

  • "C:\xampp\htdocs\basic\messages\cs-CZ\app.php"

(Note that cs-CZ is for Czech Lanuage. For German you should use de-DE etc. Use any other language if you want.)

The idea behind is that in the code ther are used only English texts and if you want to change from English to some other language this file will be used.

Now go to file config/web.php, find section "components" and paste this code:

    'components' => [
        'i18n' => [
          'translations' => [
            '*' => [
              'class' => 'yii\i18n\PhpMessageSource',
              'basePath' => '@app/messages',
              'sourceLanguage' => 'en-US',
              'fileMap' => [
                'app' => 'app.php'
              ],
            ],
          ],
        ], // end of 'i18n'

        // ... other configurations

    ], // end of 'components'
    

Explanation of the asterisk * can be found in article https://www.yiiframework.com/doc/guide/2.0/en/tutorial-i18n

You surely saw that in views and models there are texts saved like this:

Yii::t('app', 'New password'),

It means that this text belongs to category "app" and its English version (and also its ID) is "New password". So this ID will be searched in the file you just created. In my case it was the Czech file:

  • "C:\xampp\htdocs\basic\messages\cs-CZ\app.php"

Therefore open the file and paste there following code:

<?php
return [
    'New password' => 'Nové heslo',
];
?>

Now you can open the page for adding a new user and you will see than so far nothing changed :-)

We must change the language ... For now let's do it in a primitive and permanent way again in file config/web.php

$config = [
    // use your language
    // also accessible via Yii::$app->language
    'language' => 'cs-CZ',
    
    // This attribute is not necessary.
    // en-US is default value
    'sourceLanguage' => 'en-US',
    
    // ... other configs

Switching languages + session + dropdown in the top menu

First lets add to file config/params.php attributes with list of supported languages:

<?php
return [
    // ...
    'allowedLanguages' => [
        'en-US' => "English",
        'cs-CZ' => "Česky",
    ],
    'langSwitchUrl' => '/site/set-lang',
];

This list can be displayed in the main menu. Edit file:

  • C:\xampp\htdocs\basic\views\layouts\main.php

And above the Nav::widget add few rows:

    $listOfLanguages = [];
    $langSwitchUrl = Yii::$app->params["langSwitchUrl"];
    foreach (Yii::$app->params["allowedLanguages"] as $langId => $langName) {
        $listOfLanguages[] = ['label' => Yii::t('app', $langName), 'url' => [$langSwitchUrl, 'langID' => $langId]];
    }

and then add one item into Nav::widge

    echo Nav::widget([
        // ...
        'items' => [
            // ...
            ['label' => Yii::t('app', 'Language'),'items' => $listOfLanguages],
            // ...

Now in the top-right corner you can see a new drop-down-list with list of 2 languages. If one is selected, action "site/setLang" is used so we have to create it in SiteController.

Note that this approach will always redirect user to the new action and his work will be lost. Nevertheless this approach is very simple so I am using it in small projects. More complex projects may require an ajax call when language is changed and then updating texts using javascript so reload is not needed and user's work is preserved. But I expect that when someone opens the web, he/she sets the language immediately and then there is no need for further changes.

The setLang action looks like this:

    public function actionSetLang($langID = "") {
        $allowedLanguages = Yii::$app->params["allowedLanguages"];
        $langID = trim($langID);
        if ($langID !== "" && array_key_exists($langID, $allowedLanguages)) {
            Yii::$app->session->set('langID', $langID);
        }
        return $this->redirect(['site/index']);
    }

As you can see when the language is changed, redirection to site/index happens. Also mind that we are not modifying the attribute from config/web.php using Yii::$app->language, but we are saving the value into the session. The reason is that PHP deletes memory after every click, only session is kept.

We then can use the langID-value in other controllers using new method beforeAction:

    public function beforeAction($action) {

        if (!parent::beforeAction($action)) {
            return false;
        }

        Yii::$app->language = Yii::$app->session->get('langID');

        return true;
    }

.. or you can create one parent-controller named for example BaseController. All other controllers will extend it.

<?php

namespace app\controllers;

use Yii;
use yii\web\Controller;

class BaseController extends Controller {

    public function beforeAction($action) {

        if (!parent::beforeAction($action)) {
            return false;
        }

        Yii::$app->language = Yii::$app->session->get('langID');

        return true;
    }

}

As you can see in the snippet above, other controllers must contain row "use app\controllers\BaseController" + "extends BaseController"

Access rights

... text ...