WordPress首个插件问题求助：后台表单隐藏与短码功能修复

Got it, let's sort out those two problems with your WordPress plugin right away. Here's the step-by-step solution with modified code:

Problem 1: Hide Upload Form from Admin Menu #

The current test_init function outputs the upload form directly when you click the admin menu. We'll replace that form with a simple message telling users to use the shortcode on the frontend instead.

Problem 2: Make Shortcode Display Upload Form #

Right now your shortcode just returns "Hello World!"—we'll update it to render the upload form, and also ensure the file upload handling works from the frontend.

Modified Full Code #

<?php
/*
Plugin Name: Zach First Plugin
Description: Plugin to create a menu in WP
Author: Zach
Version: 0.1
*/

// Call function to create an Admin menu element
add_action('admin_menu', 'test_plugin_setup_menu');
function test_plugin_setup_menu(){
    add_menu_page( 
        'Zach Plugin Page', 
        'Zach Plugin', 
        'manage_options', 
        'test-plugin', 
        'test_init' 
    );
}

// Admin menu page content (no upload form here anymore)
function test_init(){
    ?>
    <h1>Zach First Plugin</h1>
    <p>Use the <code>[pdf]</code> shortcode on any post or page to access the file upload form on the frontend.</p>
    <?php
}

// Handle file uploads (moved to init hook so it works on frontend too)
add_action('init', 'test_handle_post');
function test_handle_post(){
    // Only process if it's a POST request and the file is set
    if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['test_upload_pdf'])){
        // Check user capability to upload files
        if(!current_user_can('upload_files')){
            wp_die('You do not have permission to upload files.');
        }

        $pdf = $_FILES['test_upload_pdf'];
        // Use WordPress media upload function
        $uploaded = media_handle_upload('test_upload_pdf', 0);
        
        // Error checking
        if(is_wp_error($uploaded)){
            echo "<p style='color:red;'>Error uploading file: " . $uploaded->get_error_message() . "</p>";
        }else{
            echo "<p style='color:green;'>File upload successful! <a href='" . wp_get_attachment_url($uploaded) . "' target='_blank'>View File</a></p>";
        }
    }
}

// Shortcode to display upload form on frontend
add_shortcode("pdf", "test_process_shortcode");
function test_process_shortcode(){
    // Check if user has permission to upload
    if(!current_user_can('upload_files')){
        return "<p>You do not have permission to upload files.</p>";
    }

    ob_start(); // Start output buffering to capture HTML
    ?>
    <h2>Upload a PDF File</h2>
    <!-- Upload form with proper enctype -->
    <form method="post" enctype="multipart/form-data">
        <input type='file' id='test_upload_pdf' name='test_upload_pdf' accept='application/pdf' required></input>
        <?php submit_button('Upload PDF') ?>
    </form>
    <?php
    return ob_get_clean(); // Return the captured HTML
}
?>

Key Changes Explained #

• Admin Menu Cleanup: The test_init function now only shows a header and instructions instead of the upload form.
• Upload Handling Hook: Moved test_handle_post to the init hook so it triggers both on admin and frontend requests (critical for processing frontend form submissions).
• Shortcode Form: Updated test_process_shortcode to render the upload form using output buffering (better practice for generating HTML in shortcodes). Also added:
  • Permission check to ensure only users with upload rights can see the form.
  • accept='application/pdf' to restrict uploads to PDF files.
  • required attribute to enforce file selection before submission.
  • Success/error messages with styling for better user feedback.

These changes will:

1. Remove the upload form from your admin menu page
2. Make the [pdf] shortcode display the upload form on frontend posts/pages
3. Ensure file uploads work correctly from the frontend with proper error handling

内容的提问来源于stack exchange，提问作者TSCAmerica.com