CodeBlanks Logo Icon CodeBlanks
Login Register

Adding packages with require

PHP course · Advanced · Lesson 36/92

Learn to add a new package with composer require and version constraints.

composer require and version constraints

The composer require monolog/monolog command adds a new package to your project. A version constraint follows the package name; for example composer require monolog/monolog:^3.5 installs 3.5 and any later 3.x version.

The ^ sign is called caret, the ~ sign is called tilde. These two are the most common version constraints and decide which sub-versions of a package are accepted.

The tilde ~ constraint

The tilde ~ sign resembles caret but gives a narrower range. The ~1.2 constraint accepts 1.2 and any later 1.x; just like ^1.2. The difference shows up at the patch level.

~1.2.3 accepts only 1.2.x versions; ^1.2.3 accepts all 1.x.x. So tilde pins the patch version, caret keeps the major version.

Exercise Version constraint resolver

Write a parseConstraint(string $c): string function. If the constraint starts with ^ return "caret", with ~ return "tilde", if it is * return "any", otherwise return "exact". Call four constraints (^3.5, ~7.8, *, 3.0.0) in turn and print in the form monolog/monolog: ^3.5 -> caret.

Show example solution 
string { if (strpos($c, "^") === 0) { return "caret"; } if (strpos($c, "~") === 0) { return "tilde"; } if ($c === "*") { return "any"; } return "exact"; }. Define $deps = ["monolog/monolog" => "^3.5", "guzzlehttp/guzzle" => "~7.8", "symfony/console" => "*", "psr/log" => "3.0.0"];. Print with foreach ($deps as $pkg => $ver) { echo $pkg . ": " . $ver . " -> " . parseConstraint($ver) . "\n"; }.
Example solution:
<?php
function parseConstraint(string $c): string {
    if (strpos($c, "^") === 0) { return "caret"; }
    if (strpos($c, "~") === 0) { return "tilde"; }
    if ($c === "*") { return "any"; }
    return "exact";
}
$deps = ["monolog/monolog" => "^3.5", "guzzlehttp/guzzle" => "~7.8", "symfony/console" => "*", "psr/log" => "3.0.0"];
foreach ($deps as $pkg => $ver) {
    echo $pkg . ": " . $ver . " -> " . parseConstraint($ver) . "\n";
}

Test yourself

  1. What does the ^3.5 constraint accept?

    • Only 3.5.0
    • 3.5 and any later 3.x
    • 4.x and later
    • All versions older than 3.5
    Show answer

    3.5 and any later 3.x — Correct. ^3.5 (caret) accepts 3.5 and any later 3.x.

  2. Complete the caret constraint

    <?php
// Version constraint: 7.8 and any later 7.x
$cfg = ["ver" => "____7.8"];
echo $cfg["ver"] . "\n";
    Show answer 
    <?php
// Version constraint: 7.8 and any later 7.x
$cfg = ["ver" => "^7.8"];
echo $cfg["ver"] . "\n";

  3. Match the version constraints

    ^1.2.3
    Accepts 1.x.x
    ~1.2.3
    Accepts 1.2.x
    1.2.3
    Only 1.2.3
    *
    Any version

All lessons in Advanced

1 PDO basics

  1. What is PDO?
  2. Connecting with PDO
  3. Running queries with query()
  4. Single row with fetch()
  5. All rows with fetchAll()
  6. Fetch mode constants
  7. Summary - PDO basics

2 Prepared statements

  1. Prepared statements with prepare()
  2. Running with execute()
  3. Binding parameters with bindParam()
  4. Binding values with bindValue()
  5. SQL injection and prevention
  6. Named placeholders
  7. Summary - Prepared statements

3 CRUD operations

  1. Inserting records with INSERT
  2. Reading records with SELECT
  3. Updating records with UPDATE
  4. Deleting records with DELETE
  5. Affected rows with rowCount()
  6. Transaction management
  7. Summary - CRUD operations

4 Project: Blog with PDO

  1. Project: Blog with PDO
  2. Database structure
  3. Adding and listing posts
  4. Editing and deleting posts
  5. Project final - Blog with PDO

5 Namespaces

  1. Defining namespaces
  2. Importing with use
  3. Aliases
  4. Global namespace
  5. Multi-level namespaces
  6. PSR-4 autoloading
  7. Summary - Namespaces

6 Composer

  1. What is Composer?
  2. The composer.json file
  3. Adding packages with require
  4. Autoload (PSR-4)
  5. Installing packages from Packagist
  6. composer update and install
  7. Summary - Composer

7 Regex

  1. Matching with preg_match()
  2. Replacing with preg_replace()
  3. All matches with preg_match_all()
  4. Character classes
  5. Quantifiers
  6. Capture groups
  7. Summary - Regex

8 JSON and API

  1. Encoding with json_encode()
  2. Parsing with json_decode()
  3. JSON error handling
  4. Content-Type with header()
  5. REST API basics
  6. HTTP methods
  7. Summary - JSON and API

9 Project: REST API

  1. Project: REST API
  2. Routing structure
  3. CRUD endpoints
  4. JSON response format
  5. Project final - REST API

10 Security

  1. Hashing with password_hash()
  2. Verifying with password_verify()
  3. SQL injection prevention
  4. XSS prevention
  5. CSRF token generation
  6. Security headers
  7. Summary - Security

11 Middleware

  1. The middleware pattern
  2. Request/Response cycle
  3. Middleware chain
  4. Auth middleware
  5. Logging middleware
  6. PSR-15 basics
  7. Summary - Middleware

12 Testing basics

  1. What is PHPUnit?
  2. Writing your first test
  3. Assertions
  4. Test layout (AAA)
  5. Test doubles (mock, stub)
  6. setUp and tearDown
  7. Summary - Testing basics

13 Design patterns

  1. The Singleton pattern
  2. The Factory pattern
  3. The Observer pattern
  4. The Strategy pattern
  5. The Decorator pattern
  6. The Adapter pattern
  7. Summary - Design patterns

14 Advanced final

  1. Challenge - PDO and API
  2. Challenge - Security app
  3. Challenge - Design patterns
  4. Challenge - Writing tests
  5. Challenge - Mini framework