add_settings_error on validating plugin options API

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.

register_setting(
    $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;
    }else{
        $options['frontend-font'] = false;
    }
    if( isset( $input['backend-font'] ) and $input['backend-font'] == true ){
        $options['backend-font'] = true;
    }else{
        $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"*/
        add_settings_error(
            '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">
			<?php
				submit_button();
				settings_fields( $this->plugin_slug ); // This prints out all hidden setting fields
				do_settings_sections( $this->plugin_slug );
				submit_button();
			?>
			</form>
		</div>
		<?php
    }

• This topic was modified 6 years, 8 months ago by ParsMizban.