Yii2 Helpers & Utility Classes

Introduction

Yii2 provides a set of helper classes to simplify common programming tasks such as string manipulation, URL generation, HTML rendering, array operations, and more. These helper classes are static, meaning they can be used directly without instantiating an object.

In this tutorial, we will explore some of the most commonly used helper classes in Yii2 and how they can make development easier and more efficient.

1. Overview of Yii2 Helpers

Yii2 helpers are organized into different classes, each handling a specific type of operation. Some of the most useful ones include:

• ArrayHelper: Simplifies array manipulation.
• Html: Assists in generating HTML elements.
• Url: Helps in creating URLs.
• StringHelper: Provides methods for string manipulation.
• FileHelper: Assists in file operations.
• BaseJson: Encodes and decodes JSON data.
• Security: Handles cryptographic operations.

Each of these helpers is part of the yii\helpers namespace and can be used anywhere in a Yii2 application.

2. Working with Yii2 Helper Classes

2.1 Using ArrayHelper

The ArrayHelper class provides various methods to manipulate arrays easily.

Extracting Values from an Array

use yii\helpers\ArrayHelper;

$users = [
    ['id' => 1, 'name' => 'Rahul'],
    ['id' => 2, 'name' => 'Ankit'],
];

$names = ArrayHelper::getColumn($users, 'name');
print_r($names); // Output: ['Rahul', 'Ankit']

Merging Arrays

$array1 = ['name' => 'Rahul', 'email' => 'rahul@example.com'];
$array2 = ['age' => 30, 'email' => rahul.singh@example.com'];

$result = ArrayHelper::merge($array1, $array2);
print_r($result);
// Output: ['name' => 'Rahul', 'email' => 'rahul.singhdoe@example.com', 'age' => 30]

2.2 Using Html Helper

The Html helper makes it easy to generate HTML elements dynamically.

Generating a Link

use yii\helpers\Html;

echo Html::a('Click Here', ['site/index'], ['class' => 'btn btn-primary']);

Creating a Form Input

echo Html::input('text', 'username', '', ['class' => 'form-control']);

2.3 Using Url Helper

The Url helper assists in generating URLs dynamically.

Creating a URL for a Controller Action

use yii\helpers\Url;

echo Url::to(['site/contact']); // Output: /index.php?r=site/contact

Creating an Absolute URL

echo Url::to(['site/contact'], true); // Output: http://example.com/index.php?r=site/contact

Using Url::toRoute() for Modules

If you are working with modules, Url::toRoute() is useful for generating route-based URLs.

$url = Url::toRoute(['/admin/user/view', 'id' => 1]);
echo $url; // Output: /admin/user/view?id=1

2.4 Using StringHelper

The StringHelper class provides various string manipulation functions.

Truncating a String

use yii\helpers\StringHelper;

$text = 'This is a long sentence that needs truncation.';
echo StringHelper::truncate($text, 20);
// Output: 'This is a long ...'

Checking If a String Starts with a Certain Word

if (StringHelper::startsWith('Hello Yii2', 'Hello')) {
    echo 'String starts with Hello';
}

2.5 Using FileHelper

The FileHelper class helps in handling file operations.

Getting File Extension

use yii\helpers\FileHelper;

$extension = FileHelper::getExtension('/path/to/file.txt');
echo $extension; // Output: 'txt'

Creating a Directory

FileHelper::createDirectory('/path/to/new/folder');

2.6 Using BaseJson

The BaseJson class is useful for encoding and decoding JSON data.

Encoding an Array to JSON

use yii\helpers\BaseJson;

$data = ['name' => 'Rahul', 'age' => 30];
echo BaseJson::encode($data);
// Output: {"name":"Rahul","age":30}

Decoding JSON to an Array

$json = '{"name":"Rahul","age":30}';
$data = BaseJson::decode($json);
print_r($data);
// Output: ['name' => 'Rahul', 'age' => 30]

2.7 Using Security Helper

The Security helper class provides cryptographic functions.

Generating a Secure Hash

use yii\base\Security;

$security = new Security();
hash = $security->generatePasswordHash('mypassword');
echo $hash;

Verifying a Password Hash

$isValid = $security->validatePassword('mypassword', $hash);
if ($isValid) {
    echo 'Password is valid';
}

Conclusion

Yii2 helpers are powerful tools that simplify many common development tasks. By using these helpers, developers can write cleaner, more efficient code. Whether you're dealing with arrays, generating HTML, working with files, or handling security operations, Yii2 helpers provide a structured and efficient way to handle these tasks.