WordPress settings api for simple settings fields

wp-settings-api-text-fields.php

<?php

add_action( 'admin_menu', 'myplugin_register_settings_menu_page' );
add_action( 'admin_init', 'myplugin_register_settings_fields' );

function myplugin_register_settings_menu_page() {
	add_options_page( 'My plugin', 'My plugin', 'manage_options', 'myplugin-settings', 'myplugin_display_settings_menu' );
}

function myplugin_register_settings_fields() {
	add_settings_section( 'myplugin-settings-analytics', 'Google Analytics Settings', null, 'myplugin-settings' );
	
	// Tracking ID
	add_settings_field(
		'myplugin_google_analytics_tracking_id',
		'Tracking ID',
		'myplugin_setting_field_text',
		'myplugin-settings',
		'myplugin-settings-analytics',
		array(
			'option_name' => 'myplugin_google_analytics_tracking_id',
			'description' => 'Find your Tracking ID in your <a href="https://analytics.google.com/" target="_blank">Analytics</a> settings under the Property Settings tab.',
		)
	);
	
	register_setting( 'myplugin_setting_fields', 'myplugin_google_analytics_tracking_id', array( 'sanitize_callback' => 'myplugin_validate_settings' ) );
	
	// View ID
	add_settings_field(
		'myplugin_google_analytics_view_id',
		'View ID',
		'myplugin_setting_field_text',
		'myplugin-settings',
		'myplugin-settings-analytics',
		array(
			'option_name' => 'myplugin_google_analytics_view_id',
			'description' => 'Find your View ID in the Analytics admin area under View > View Settings.',
		)
	);
	
	register_setting( 'myplugin_setting_fields', 'myplugin_google_analytics_view_id', array( 'sanitize_callback' => 'myplugin_validate_settings' ) );
	
	
	// API Key
	add_settings_field(
		'myplugin_google_analytics_api_key',
		'API Key',
		'myplugin_setting_field_text',
		'myplugin-settings',
		'myplugin-settings-analytics',
		array(
			'option_name' => 'myplugin_google_analytics_api_key',
			'description' => 'For information on creating a Google Analytics API Key, <a href="https://developers.google.com/analytics/devguides/reporting/core/v4/authorization" target="_blank">click here</a>. Once you have an API key, be sure to share your Analytics account access with the service account email (see <a href="https://developers.google.com/analytics/devguides/reporting/core/v4/quickstart/service-php" target="_blank">Reporting API 4: Enable the API</a>).',
		)
	);
	
	register_setting( 'myplugin_setting_fields', 'myplugin_google_analytics_api_key', array( 'sanitize_callback' => 'myplugin_validate_settings' ) );
}

function myplugin_validate_settings( $input ) {
	// Check our textbox option field contains no HTML tags - if so strip them out
	// $input['text_string'] = wp_filter_nohtml_kses( $input['text_string'] );
	
	return $input; // return validated input
}

function myplugin_setting_field_text( $args ) {
	$option_name = isset($args['option_name']) ? $args['option_name'] : false;
	if ( !$option_name ) return;
	
	$id = isset($args['id']) ? $args['id'] : $option_name;
	
	$type = isset($args['type']) ? $args['type'] : 'text';
	
	$name = isset($args['field_name']) ? $args['field_name'] : $option_name;
	
	$value = get_option( $args['option_name'] );
	
	$atts = array(
		'id' => $id,
		'name' => $name,
		'type' => $type,
		'value' => $value,
		'size' => 60,
	);
	
	echo '<input ';
	foreach( $atts as $k => $v ) echo $k . '="' . esc_attr($v) . '" ';
	echo '/>';
	
	if ( isset($args['description']) ) {
		echo '<div class="description">', wpautop($args['description']), '</div>';
	}
}

function myplugin_display_settings_menu() {
	?>
	<div class="wrap">
		
		<h2>My Plugin Settings</h2>
		
		<form action="options.php" method="post">
			
			<?php wp_nonce_field( 'myplugin-save-settings' ); ?>
			
			<?php settings_fields( 'myplugin_setting_fields' ); ?>
			
			<?php do_settings_sections( 'myplugin-settings' ); ?>
			
			<?php submit_button(); ?>
		
		</form>
	
	</div>
	<?php
}