Using WordPress ‘core_upgrade_preamble()’ PHP function

The core_upgrade_preamble() WordPress PHP function displays a WordPress upgrade form. This form is typically used for downloading the latest WordPress version or for upgrading automatically.

Usage

To use core_upgrade_preamble(), simply call the function. Here’s a custom example:

// Call the core_upgrade_preamble() function
core_upgrade_preamble();

This will display the WordPress upgrade form.

Parameters

The core_upgrade_preamble() function does not have any parameters.

More information

See WordPress Developer Resources: core_upgrade_preamble()

This function is part of the WordPress Core and is typically used in the WordPress admin dashboard. It is not recommended to be used directly in your theme or plugin code. Instead, WordPress updates should be handled through the admin dashboard.

Examples

Basic Usage

This is how you use core_upgrade_preamble() in its simplest form.

// Display the WordPress upgrade form
core_upgrade_preamble();

Inside a Custom Function

You can call core_upgrade_preamble() inside your custom function.

function my_custom_upgrade() {
  // Display the WordPress upgrade form
  core_upgrade_preamble();
}
my_custom_upgrade();

Conditional Upgrade Display

You can use core_upgrade_preamble() within a conditional statement to control when the upgrade form is shown.

if (current_user_can('update_core')) {
  // Only show the upgrade form to users who have the 'update_core' capability
  core_upgrade_preamble();
}

Within a Custom Page

You can create a custom page in your WordPress admin area and call core_upgrade_preamble() from there.

add_action('admin_menu', 'my_custom_page');

function my_custom_page() {
  add_menu_page('Custom Upgrade Page', 'Custom Upgrade', 'update_core', 'custom_upgrade', 'display_upgrade_form');
}

function display_upgrade_form() {
  // Display the WordPress upgrade form
  core_upgrade_preamble();
}

AJAX Request

Use core_upgrade_preamble() within an AJAX request to dynamically display the upgrade form.

add_action('wp_ajax_my_custom_upgrade', 'my_custom_upgrade_callback');

function my_custom_upgrade_callback() {
  if (current_user_can('update_core')) {
    // Only show the upgrade form to users who have the 'update_core' capability
    core_upgrade_preamble();
  }
  wp_die(); // this is required to terminate immediately and return a proper response
}

In your JavaScript file:

jQuery(document).ready(function($) {
  var data = {
    'action': 'my_custom_upgrade'
  };

  $.post(ajaxurl, data, function(response) {
    alert('Got this from the server: ' + response);
  });
});

This will send an AJAX request and display the upgrade form when the action my_custom_upgrade is called.