Kotchasan Framework Documentation

Kotchasan Framework Documentation

Kotchasan\View

EN 06 Feb 2026 06:21

Kotchasan\View

View is the class responsible for managing the presentation layer in the MVC pattern, handling HTML generation and template management.

Table of Contents

  1. Overview
  2. Installation and Setup
  3. Core Methods
  4. Usage Examples
  5. Best Practices
  6. Common Mistakes
  7. Related Classes

Overview

The View class is a crucial component of the Kotchasan Framework that handles:

  • Template Management: Manages HTML templates and content replacement using regex patterns
  • Asset Management: Manages CSS, JavaScript files, and meta tags
  • Content Rendering: Creates complete HTML output from templates
  • Header Management: Controls HTTP headers and responses
  • Script Integration: Adds JavaScript files and inline scripts

When to use:

  • When generating HTML pages in MVC controller
  • When building email templates
  • When creating dynamic content with template placeholders
  • When managing page assets (CSS/JS) programmatically

Installation and Setup

Requirements

  • PHP 7.4 or higher
  • Kot chasan Framework
  • HTML template files (.html)

Basic Setup

use Kotchasan\View;

// Create view instance
$view = View::create();

The View class automatically initializes with these default values in templates:

  • /{WEBTITLE}/ - Site title from configuration
  • /{WEBDESCRIPTION}/ - Site description from configuration
  • /{WEBURL}/ - Website base URL
  • /{SKIN}/ - Current template/skin path

Core Methods

create()

Creates a new View instance (Factory method).

Signature:

public static function create(): static

Returns: View instance

Example:

$view = View::create();

setContents()

Sets content placeholders for template replacement.

Signature:

public function setContents(array $array): void

Parameters:

  • $array (array) - Key-value pairs where keys are patterns (e.g., '/{NAME}/') and values are replacement strings

Example:

$view->setContents([
    '/{TITLE}/' => 'Page Title',
    '/{CONTENT}/' => 'Page content here',
    '/{COPYRIGHT}/' => '© 2024 My Website'
]);

setContentsAfter()

Sets content to be replaced AFTER the template is rendered. Useful for final modifications.

Signature:

public function setContentsAfter(array $array): void

Parameters:

  • $array (array) - Key-value pairs for post-rendering replacement

Example:

$view->setContentsAfter([
    '/{FINAL_SCRIPT}/' => '<script>console.log("Page loaded");</script>'
]);

addCSS()

Adds a CSS file link to the HTML head.

Signature:

public function addCSS(string $url): void

Parameters:

  • $url (string) - URL or path to the CSS file

Example:

$view->addCSS('/css/bootstrap.min.css');
$view->addCSS('/css/custom.css');

Generated HTML:

<link rel="stylesheet" href="/css/bootstrap.min.css">
<link rel="stylesheet" href="/css/custom.css">

addJavascript()

Adds a JavaScript file to the HTML head.

Signature:

public function addJavascript(string $url): void

Parameters:

  • $url (string) - URL or path to the JavaScript file

Example:

$view->addJavascript('/js/jquery.min.js');
$view->addJavascript('/js/app.js');

Generated HTML:

<script src="/js/jquery.min.js"></script>
<script src="/js/app.js"></script>

addScript()

Adds inline JavaScript code to be inserted in the head section.

Signature:

public function addScript(string $script): void

Parameters:

  • $script (string) - JavaScript code (without <script> tags)

Example:

$view->addScript('
    $(document).ready(function() {
        console.log("Page ready");
    });
');

Generated HTML:

<script>
    $(document).ready(function() {
        console.log("Page ready");
    });
</script>

setHeaders ()

Sets HTTP headers for the response.

Signature:

public function setHeaders(array $array): void

Parameters:

  • $array (array) - Key-value pairs of header names and values

Example:

$view->setHeaders([
    'Content-Type' => 'text/html; charset=utf-8',
    'X-Frame-Options' => 'DENY',
    'X-Content-Type-Options' => 'nosniff'
]);

setMetas()

Adds custom meta tags to the HTML head.

Signature:

public function setMetas(array $array): void

Parameters:

  • $array (array) - Key-value pairs where values are complete meta tag HTML

Example:

$view->setMetas([
    'description' => '<meta name="description" content="Website description">',
    'keywords' => '<meta name="keywords" content="keyword1, keyword2">',
    'og:title' => '<meta property="og:title" content="Page Title">'
]);

renderHTML()

Renders the final HTML output by processing the template with all set content.

Signature:

public function renderHTML(?string $template = null): string

Parameters:

  • $template (string|null) - Template content or null to use 'index.html' from Template::load()

Returns: string - The rendered HTML

Example:

// Use default template (index.html)
$html = $view->renderHTML();

// Use custom template content
$template = '<html><head>{/TITLE/}</head><body>{/CONTENT/}</body></html>';
$html = $view->renderHTML($template);

output()

Sends HTTP headers and outputs the content to the browser.

Signature:

public function output(string $content): void

Parameters:

  • $content (string) - The content to output

Example:

$html = $view->renderHTML();
$view->output($html);

back()

Creates a URL for navigation, preserving query string parameters from current request.

Signature:

public static function back(array|string $f): string

Parameters:

  • $f (array|string) - Query string or parameter modifications

Returns: string - Modified URL

Note: Requires active HTTP request context (Request object must be initialized)

Example:

// In a controller with active request
$backUrl = View::back('module=home&action=index');
// Returns: current URL with modified/added parameters

array_value()

Safely retrieves a value from an array with a default fallback.

Signature:

public static function array_value(array $array, string $key, mixed $default = ''): mixed

Parameters:

  • $array (array) - The source array
  • $key (string) - The key to retrieve
  • $default (mixed) - Default value if key doesn't exist (default: '')

Returns: mixed - The value or default

Example:

$data = ['name' => 'John', 'age' => 30];

$name = View::array_value($data, 'name', 'Anonymous'); // Returns: 'John'
$city = View::array_value($data, 'city', 'Unknown');   // Returns: 'Unknown'

object_value()

Safely retrieves a property value from an object with a default fallback.

Signature:

public static function object_value(object $source, string $key, mixed $default = ''): mixed

Parameters:

  • $source (object) - The source object
  • $key (string) - The property name to retrieve
  • $default (mixed) - Default value if property doesn't exist (default: '')

Returns: mixed - The property value or default

Example:

$user = (object)['name' => 'Jane', 'email' => 'jane@example.com'];

$name = View::object_value($user, 'name', 'Anonymous');  // Returns: 'Jane'
$phone = View::object_value($user, 'phone', 'N/A');      // Returns: 'N/A'

Usage Examples

1. Basic Page Rendering

use Kotchasan\View;

class HomeController
{
    public function index()
    {
        // Create view
        $view = View::create();

        // Set page content
        $view->setContents([
            '/{TITLE}/' => 'Welcome to Our Website',
            '/{HEADING}/' => 'Welcome!',
            '/{CONTENT}/' => 'This is the homepage content.',
            '/{YEAR}/' => date('Y')
        ]);

        // Add CSS
        $view->addCSS('/css/style.css');

        // Add JavaScript
        $view->addJavascript('/js/main.js');

        // Render and output
        $html = $view->renderHTML();
        $view->output($html);
    }
}

2. Product Detail Page

use Kotchasan\View;

class ProductController
{
    public function show($id)
    {
        // Fetch product data
        $product = $this->getProduct($id);

        // Create view
        $view = View::create();

        // Set content
        $view->setContents([
            '/{TITLE}/' => $product->name . ' - Our Store',
            '/{PRODUCT_NAME}/' => htmlspecialchars($product->name),
            '/{PRODUCT_PRICE}/' => number_format($product->price, 2),
            '/{PRODUCT_DESCRIPTION}/' => nl2br(htmlspecialchars($product->description)),
            '/{PRODUCT_IMAGE}/' => '<img src="'.$product->image.'" alt="'.htmlspecialchars($product->name).'">'
        ]);

        // Add product-specific assets
        $view->addCSS('/css/product.css');
        $view->addJavascript('/js/product-gallery.js');

        // Add structured data for SEO
        $view->addScript('
            var productData = {
                id: '.$product->id.',
                name: "'.addslashes($product->name).'",
                price: '.$product->price.'
            };
        ');

        return $view->renderHTML();
    }
}

3. SEO-Optimized Page

$view = View::create();

// Set page content
$view->setContents([
    '/{TITLE}/' => 'Top Products 2024 - Best Deals',
    '/{CONTENT}/' => $pageContent
]);

// Add comprehensive SEO meta tags
$view->setMetas([
    'description' => '<meta name="description" content="Find the best products with amazing deals in 2024">',
    'keywords' => '<meta name="keywords" content="products, deals, 2024, shopping">',
    'og:title' => '<meta property="og:title" content="Top Products 2024">',
    'og:description' => '<meta property="og:description" content="Find the best products">',
    'og:image' => '<meta property="og:image" content="https://example.com/image.jpg">',
    'og:url' => '<meta property="og:url" content="https://example.com/products">',
    'canonical' => '<link rel="canonical" href="https://example.com/products">'
]);

// Add security headers
$view->setHeaders([
    'X-Frame-Options' => 'SAMEORIGIN',
    'X-Content-Type-Options' => 'nosniff',
    'X-XSS-Protection' => '1; mode=block'
]);

$html = $view->renderHTML();

4. Email Template

use Kotchasan\View;

class EmailService
{
    public function sendWelcomeEmail($user)
    {
        $view = View::create();

        // Set email template content
        $view->setContents([
            '/{USER_NAME}/' => htmlspecialchars($user->name),
            '/{USER_EMAIL}/' => htmlspecialchars($user->email),
            '/{ACTIVATION_LINK}/' => $this->generateActivationLink($user),
            '/{WEBSITE_NAME}/' => 'Our Website',
            '/{WEBSITE_URL}/' => 'https://example.com',
            '/{SUPPORT_EMAIL}/' => 'support@example.com'
        ]);

        // Load email template
        $template = file_get_contents(ROOT_PATH.'templates/emails/welcome.html');
        $emailHTML = $view->renderHTML($template);

        // Send email
        mail($user->email, 'Welcome!', $emailHTML, 'Content-Type: text/html');
    }
}

5. AJAX JSON Response with HTML

use Kotchasan\View;

class CommentController
{
    public function add()
    {
        try {
            // Save comment
            $comment = $this->saveComment($_POST);

            // Generate HTML for the new comment
            $view = View::create();
            $view->setContents([
                '/{COMMENT_ID}/' => $comment->id,
                '/{AUTHOR_NAME}/' => htmlspecialchars($comment->author_name),
                '/{COMMENT_TEXT}/' => nl2br(htmlspecialchars($comment->text)),
                '/{COMMENT_DATE}/' => date('M d, Y H:i', strtotime($comment->created_at))
            ]);

            $template = file_get_contents(ROOT_PATH.'templates/comment-item.html');
            $commentHTML = $view->renderHTML($template);

            // Return JSON with HTML
            header('Content-Type: application/json');
            echo json_encode([
                'success' => true,
                'html' => $commentHTML,
                'message' => 'Comment added successfully'
            ]);

        } catch (Exception $e) {
            header('Content-Type: application/json', true, 400);
            echo json_encode([
                'success' => false,
                'message' => $e->getMessage()
            ]);
        }
    }
}

Best Practices

1. Template Organization

// Organize templates by purpose
// templates/
//   ├── layouts/
//   │   ├── main.html
//   │   └── admin.html
//   ├── pages/
//   │   ├── home.html
//   │   └── about.html
//   ├── emails/
//   │   └── welcome.html
//   └── partials/
//       ├── header.html
//       └── footer.html

2. Security: Always Escape User Input

// ✅ GOOD: Escape user input
$view->setContents([
    '/{USER_NAME}/' => htmlspecialchars($userName, ENT_QUOTES, 'UTF-8'),
    '/{SAFE_HTML}/' => $trustedContent // Only for trusted content
]);

// ❌ BAD: Direct user input
$view->setContents([
    '/{USER_NAME}/' => $_POST['name'] // XSS vulnerability!
]);

3. Performance: Minimize Assets

// ✅ GOOD: Use combined/minified files
$view->addCSS('/css/combined.min.css');
$view->addJavascript('/js/combined.min.js');

// ❌ BAD: Too many individual files
$view->addCSS('/css/bootstrap.css');
$view->addCSS('/css/font-awesome.css');
$view->addCSS('/css/custom.css');
$view->addCSS('/css/responsive.css');
// ... (multiple HTTP requests)

4. Asset Versioning for Cache Busting

$version = '1.2.5'; // Update when files change
$view->addCSS('/css/app.css?v=' . $version);
$view->addJavascript('/js/app.js?v=' . $version);

5. Separate Concerns

// ✅ GOOD: Controller prepares data, View renders
class ProductController
{
    public function show($id)
    {
        // Business logic
        $product = $this->productService->getById($id);
        $relatedProducts = $this->productService->getRelated($id);

        // View rendering
        return $this->renderProductView($product, $relatedProducts);
    }

    private function renderProductView($product, $related)
    {
        $view = View::create();
        // ... set contents
        return $view->renderHTML();
    }
}

// ❌ BAD: Mixed concerns
class ProductController
{
    public function show($id)
    {
        $view = View::create();
        $product = DB::table('products')->find($id); // Business logic in view method
        $view->setContents(['/{NAME}/' => $product->name]);
        return $view->renderHTML();
    }
}

Common Mistakes

❌ Mistake 1: Not Escaping User Input

// WRONG - XSS vulnerability
$view->setContents([
    '/{COMMENT}/' => $_POST['comment']
]);

// CORRECT
$view->setContents([
    '/{COMMENT}/' => htmlspecialchars($_POST['comment'], ENT_QUOTES, 'UTF-8')
]);

❌ Mistake 2: Wrong Pattern Format

// WRONG - Missing regex delimiters
$view->setContents([
    '{TITLE}' => 'My Title'  // Won't work!
]);

// CORRECT - Use regex pattern format
$view->setContents([
    '/{TITLE}/' => 'My Title'
]);

❌ Mistake 3: Forgetting to Render

// WRONG - Nothing will be output
$view = View::create();
$view->setContents(['/{TITLE}/' => 'Test']);
// Missing: $view->renderHTML()

// CORRECT
$view = View::create();
$view->setContents(['/{TITLE}/' => 'Test']);
$html = $view->renderHTML();
$view->output($html);

❌ Mistake 4: Headers After Output

// WRONG - Headers must be set before any output
echo "Something";
$view->setHeaders(['Content-Type' => 'application/json']); // Too late!

// CORRECT - Set headers first
$view = View::create();
$view->setHeaders(['Content-Type' => 'text/html; charset=utf-8']);
$html = $view->renderHTML();
$view->output($html);
  • Template - Template loading and processing engine
  • Controller - MVC controller base class
  • Database - Database operations for dynamic content

Additional Notes

💡 Tip: The View class uses regex-based replacement. Patterns like /{NAME}/ are replaced using preg_replace(). Make sure your patterns are valid regex patterns.

⚠️ Warning: The back() method requires an active HTTP request context. It will fail if called outside of a web request (e.g., in CLI scripts).

ℹ️ Note: All CSS and JavaScript added via addCSS() and addJavascript() are automatically inserted before the closing </head> tag during renderHTML().

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