扩展CodeIgniter的MY_Parser，实现页眉页脚自动加载解析

To eliminate repeating header and footer parse calls in every controller, you can extend CodeIgniter's base CI_Parser class with a custom subclass that handles layout rendering automatically. Here's a straightforward implementation:

Step 1: Create the Custom Parser Class #

Make a file named MY_Parser.php in your application/core directory. This class will inherit from CI_Parser and add logic to include headers/footers by default:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class MY_Parser extends CI_Parser {

    protected $CI;

    public function __construct() {
        parent::__construct();
        $this->CI =& get_instance(); // Access the CI instance to retrieve theme settings
    }

    /**
     * Parse template with automatic header/footer inclusion
     * @param string $template Path to your main content template
     * @param array $data Data to pass to all templates
     * @param bool $return Whether to return output instead of sending to browser
     * @param bool $include_layout Toggle header/footer (default: true)
     * @return string|null
     */
    public function parse($template, $data = array(), $return = FALSE, $include_layout = TRUE) {
        $output = '';

        // Add header if layout is enabled
        if ($include_layout) {
            $header_path = $this->CI->settings['theme'] . '/header';
            $output .= parent::parse($header_path, $data, TRUE);
        }

        // Add main content template
        $output .= parent::parse($template, $data, TRUE);

        // Add footer if layout is enabled
        if ($include_layout) {
            $footer_path = $this->CI->settings['theme'] . '/footer';
            $output .= parent::parse($footer_path, $data, TRUE);
        }

        // Handle return vs direct output
        if ($return) {
            return $output;
        }

        $this->CI->output->append_output($output);
    }
}

Step 2: Simplify Controller Code #

Now you can replace your three separate parse calls with a single line—header and footer will load automatically:

// Old, repetitive code:
// $this->parser->parse($this->settings['theme'].'/header', $data);
// $this->parser->parse($this->settings['theme'].'/register', $data);
// $this->parser->parse($this->settings['theme'].'/footer', $data);

// New, clean code:
$this->parser->parse($this->settings['theme'].'/register', $data);

Step 3: Skip Layout for Specific Pages #

If you need a page without header/footer (like a modal or API response), pass false as the fourth parameter:

// No header/footer for this page
$this->parser->parse($this->settings['theme'].'/modal_content', $data, FALSE, FALSE);

Alternative: Dedicated Layout Method #

If you want to keep the original parse() method intact for non-layout templates, add a separate parse_layout() method instead:

// Inside MY_Parser.php
public function parse_layout($main_template, $data = array(), $return = FALSE) {
    $output = '';

    // Parse header
    $header_path = $this->CI->settings['theme'] . '/header';
    $output .= parent::parse($header_path, $data, TRUE);

    // Parse main content
    $output .= parent::parse($main_template, $data, TRUE);

    // Parse footer
    $footer_path = $this->CI->settings['theme'] . '/footer';
    $output .= parent::parse($footer_path, $data, TRUE);

    if ($return) {
        return $output;
    }

    $this->CI->output->append_output($output);
}

Usage in controller:

$this->parser->parse_layout($this->settings['theme'].'/register', $data);

Key Notes #

• Ensure $this->settings['theme'] is accessible via the CI instance (e.g., loaded in your base controller or as a config item).
• CodeIgniter's default subclass prefix is MY_—if you changed this in config/config.php, adjust the class name to match your custom prefix.

内容的提问来源于stack exchange，提问作者Rangka Kacang