# Uri\_helper

This utility library offers a set of functions for managing **URLs**, **handling redirects**, **sanitizing input**, **generating slugs**, and **processing request URIs** in web applications.

## Nginx in `Uri_helper`

Since `Uri_helper` provides functions for handling request URIs and generating structured URLs, proper Nginx configuration is required to **remove `index.php` from URLs** and allow `request_uri()` to function correctly.

### **Pretty URLs**

```nginx
location / {
    try_files $uri $uri/ /index.php?$query_string;
}
```

* If the requested URL matches a file or directory, it serves it directly.
* Otherwise, the request is rewritten to `index.php`, ensuring `request_uri()` processes a **clean and structured URL**.

This ensures URLs like:

`https://phpfast.net/products?page=2` remain structured without unnecessary slashes or `index.php` in the URL.

### **Handling Redirects Efficiently**

The `redirect()` function in `Uri_helper` uses PHP’s `header('Location: ...')` method for redirection. However, on Nginx, it is possible to leverage **server-level redirection for efficiency**.

**Optimizing Redirects in Nginx**\
Instead of handling all redirects in PHP, you can configure **Nginx to process common redirects** like forcing HTTPS or redirecting old URLs:

```nginx
server {
    listen 80;
    server_name phpfast.net;
    return 301 https://$server_name$request_uri;
}
```

* Redirects HTTP to HTTPS without relying on PHP.
* Reduces the need for `redirect()` calls in the application, **improving performance**.

### Supporting Clean Request URIs

The `request_uri()` function in `Uri_helper` ensures clean URL formatting, **removing unnecessary slashes** and normalizing paths. However, Nginx needs to pass the correct `$_SERVER['REQUEST_URI']` to PHP.

**Ensure Correct Request URI Handling in Nginx**

```nginx
fastcgi_param REQUEST_URI $request_uri;
```

* Ensures `request_uri()` receives the correct request path.
* Prevents duplicate slashes (`//`) in URLs from being processed incorrectly.

Example Usage with `request_uri()` in PHP:

```php
echo request_uri('https://phpfast.net//user/info');
// Output: user/info
```

Without proper configuration, Nginx may pass incorrect paths, **leading to unexpected results** in `request_uri()`.

## Functions in Uri\_helper

### `request_uri()`

* Retrieves **the clean request URI** from `$_SERVER['REQUEST_URI']`.
* **Removes extra slashes** and normalizes the path.
* **Redirects if necessary** to enforce a clean URL structure.

Example:

```php
echo request_uri('https://phpfast.net/user/info/');
// Output: user/info/

echo request_uri('https://phpfast.net/user//info//');
// Output: user/info/

echo request_uri('https://phpfast.net/user/info?page=3');
// Output: user/info/

echo request_uri('https://phpfast.net/');
// Output: empty
```

### `base_url()` 

* **Generates the base URL** for the application.
* **Retrieves the `app_url` from the config file** if not already stored in `$base_url`.
* **Trims extra slashes and handles query strings**, ensuring a **clean and structured URL**.

```php
echo base_url('products?page=2');
// Output: https://phpfast.net/products?page=2
```

### `redirect()`

* **Redirects the user** to another URL using the `header()` function.
* `exit();` ensures that no further code is executed after redirection.

Example:

```php
redirect('https://phpfast.net/dashboard');
```

### `sanitize_url()`

* **Sanitizes URLs** by removing invalid characters.
* Uses `FILTER_SANITIZE_URL`, a built-in PHP filter.

Example:

```php
echo sanitize_url('https://phpfast.net/<script>alert(1)</script>');
// Output: https://phpfast.net/ AND alert(1)
```

### `url_slug()`

* **Converts UTF-8 strings into SEO-friendly slugs**.
* **Removes special characters**, spaces, and accents (e.g., `Đ` → `D`).
* **Replaces spaces with a delimiter (`-` by default)**.

Example:

```php
echo url_slug('New Products in 2025!');
// Output: new-products-in-2025
```

<table data-header-hidden><thead><tr><th width="295"></th><th></th></tr></thead><tbody><tr><td><strong>Function</strong></td><td><strong>Purpose</strong></td></tr><tr><td><code>base_url()</code></td><td>Generates the base URL of the application.</td></tr><tr><td><code>redirect()</code></td><td>Redirects to another URL.</td></tr><tr><td><code>sanitize_url()</code></td><td>Cleans a URL from invalid characters.</td></tr><tr><td><code>url_slug()</code></td><td>Converts a UTF-8 string into a slug.</td></tr><tr><td><code>request_uri()</code></td><td>Retrieves the clean request URI.</td></tr></tbody></table>


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