Plugin Page showing Warning: call_user_func_array() expects parameter 1 - php

Question

I am making a plugin and when i add a page for managing_option the page is showing me
Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘myplugin_options_page’ not found or invalid function name in D:\xampp\htdocs\connect\wp-includes\class-wp-hook.php on line 286
Please find below the code i am using for the plugin
Main Page
<?php
/*
Plugin Name: Name
URI: https://example.com/
Description: abc
Author: Pratik Purohit
License: GPLv2 or later
*/
function myplugin_register_settings() {
add_option( ‘myplugin_option_name’, ‘This is my option value.’);
register_setting( ‘myplugin_options_group’, ‘myplugin_option_name’, ‘myplugin_callback’ );
}
add_action( ‘admin_init’, ‘myplugin_register_settings’ );
function myplugin_register_options_page() {
add_options_page(‘Page Title’, ‘Plugin Menu’, ‘manage_options’, ‘myplugin’, ‘myplugin_options_page’);
}
add_action(‘admin_menu’, ‘myplugin_register_options_page’);
Managing page
<?php function myplugin_options_page()
{
?>
<div>
<?php screen_icon(); ?>
<h2>My Plugin Page Title</h2>
<form method=”post” action=”options.php”>
<?php settings_fields( ‘myplugin_options_group’ ); ?>
<h3>This is my option</h3>
<p>Some text here.</p>
<table>
<tr valign=”top”>
<th scope=”row”><label for=”myplugin_option_name”>Label</label></th>
<td><input type=”text” id=”myplugin_option_name” name=”myplugin_option_name” value=”<?php echo get_option(‘myplugin_option_name’); ?>” /></td>
</tr>
</table>
<?php submit_button(); ?>
</form>
</div>
<?php
} ?>

Answer 1

You need to put your myplugin_options_page function before this line..
add_options_page(‘Page Title’, ‘Plugin Menu’, ‘manage_options’, ‘myplugin’, ‘myplugin_options_page’);
.. because Wordpress is trying to callback your function using the call_user_func_array PHP function, and throws an error because the function has not been found.
If you've defined the myplugin_options_page function in another file, you should add a require (doc) to your main page in order to include your function before the execution of the add_options_page().