I am developing a plugin which uses options API.

I defined a class that uses a function to sanitize the inputs, but when I submit the options form, It displays errors and info twice.

And also I didn't succeed at displaying the error messages.

What is the proper way to display the successful and error messages on validation of options form?

Thank you.

    $this->plugin_slug, // option_group
    $this->plugin_slug, // option_name, for name property of tags
    [$this, 'process_inputs'] // sanitize_callback

public function process_inputs( $input ){
    // sanitize functions:
    // sanitize_email(), sanitize_file_name(), sanitize_html_class(), sanitize_key(), sanitize_meta(), sanitize_mime_type(),
    // sanitize_option(), sanitize_sql_orderby(), sanitize_text_field(), sanitize_textarea_field(), sanitize_title(),
    // sanitize_title_for_query(), sanitize_title_with_dashes(), sanitize_user()
    $options = [];
    if( isset( $input['frontend-font'] ) and $input['frontend-font'] == true ) {
        $options['frontend-font'] = true;
        $options['frontend-font'] = false;
    if( isset( $input['backend-font'] ) and $input['backend-font'] == true ){
        $options['backend-font'] = true;
        $options['backend-font'] = false;

    // add error/update messages
    // check if the user have submitted the settings
    // wordpress will add the "settings-updated" $_GET parameter to the url
    if ( isset( $_GET['settings-updated'] ) ) {
        // add settings saved message with the class of "updated"*/
            'persianfont_messages', // Slug title of setting
            'wporg_message', // Slug-name , Used as part of 'id' attribute in HTML output.
            __( 'settings saved.', 'persianfont' ), // message text, will be shown inside styled <div> and <p> tags
            'error' // Message type, controls HTML class. Accepts 'error' or 'updated'.

    return $options;

 * Settings page display callback.
function settings_page_content() {
    // check user capabilities
    if ( ! current_user_can( 'manage_options' ) ) { return; }

    //var_dump( wp_load_alloptions() ); // print all options

    // show error/update messages
    settings_errors( 'persianfont_messages' );
    <div class="wrap">
        <h1 class="wp-heading-inline"><?php echo esc_html($this->page_title); ?></h1>
        <form method="post" action="options.php">
            settings_fields( $this->plugin_slug ); // This prints out all hidden setting fields
            do_settings_sections( $this->plugin_slug );

2 Answers 2


If you are use add_menu_page() or add_submenu_page() to add setting pages,Try add this function in your code:

  • I currently added that Aug 17, 2017 at 19:20
  • is it ok?if not,do you mind past the complete code?
    – Amos Lee
    Aug 17, 2017 at 21:50
  • I added another function too Aug 18, 2017 at 6:15

No need to add settings_errors beside the form
WordPress do that when need
So remove the line :

settings_errors( 'persianfont_messages' );
  • Be aware the settings_error is automatically added ONLY in the "Settings" menu. If your page is in "Tools" or any other menu, you need to add it manually. Apr 10, 2021 at 21:00

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