Example settings page for featuring a specific post somewhere for client sites

example-settings.php

<?php
/*
 * Sample settings page
 * forked from Tom McFarlin's more extensive example https://github.com/tommcfarlin/WordPress-Settings-Sandbox/
 *
 * @author Brian Krogsgard
 */

/**
 * This function introduces the theme options into a top-level 
 * 'Infomedia' menu.
 */
function infomedia_settings_theme_menu() {
	
	add_menu_page(
		'Infomedia Settings',					// The value used to populate the browser's title bar when the menu page is active
		'Infomedia Settings',					// The text of the menu in the administrator's sidebar
		'manage_options',					// What roles are able to access the menu
		'infomedia_menu',				// The ID used to bind submenu items to this menu 
		'infomedia_display'				// The callback function used to render this menu
	);

} // end infomedia_settings_theme_menu
add_action( 'admin_menu', 'infomedia_settings_theme_menu' );

/**
 * Renders a simple page to display for the theme menu defined above.
 */
function infomedia_display() {
?>
	<!-- Create a header in the default WordPress 'wrap' container -->
	<div class="wrap">
	
		<div id="icon-themes" class="icon32"></div>
		<h2>Infomedia Options</h2>
		<?php settings_errors(); ?>
		
		<form method="post" action="options.php">
			<?php

				settings_fields( 'infomedia_inputs' );
				do_settings_sections( 'infomedia_inputs' );

				submit_button();

			?>
		</form>
		
	</div><!-- /.wrap -->
<?php
} // end infomedia_display

/* ------------------------------------------------------------------------ *
 * Setting Registration
 * ------------------------------------------------------------------------ */ 


/**
 * Initializes the theme's input example by registering the Sections,
 * Fields, and Settings. This particular group of options is used to demonstration
 * validation and sanitization.
 *
 * This function is registered with the 'admin_init' hook.
 */ 
function infomedia_initialize_inputs() {

	if( false == get_option( 'infomedia_inputs' ) ) {	
		add_option( 'infomedia_inputs' );
	} // end if

	add_settings_section(
		'inputs_section',
		'Infomedia custom options',
		'infomedia_inputs_callback',
		'infomedia_inputs'
	);
	
	add_settings_field(
		'Feature Physician',
		'Feature Physician',
		'infomedia_feature_post_callback',
		'infomedia_inputs',
		'inputs_section'
	);
		
	register_setting(
		'infomedia_inputs',
		'infomedia_inputs',
		'infomedia_validate_inputs'
	);
	

} // end infomedia_initialize_inputs
add_action( 'admin_init', 'infomedia_initialize_inputs' );

/* ------------------------------------------------------------------------ *
 * Section Callbacks
 * ------------------------------------------------------------------------ */ 



/**
 * This function provides a simple description for the Input Examples page.
 *
 * It's called from the 'infomedia_intialize_inputs_options' function by being passed as a parameter
 * in the add_settings_section function.
 */
function infomedia_inputs_callback() {
	echo '<p>Choose custom options.</p>';
} // end infomedia_general_options_callback

/* ------------------------------------------------------------------------ *
 * Field Callbacks
 * ------------------------------------------------------------------------ */ 


function infomedia_feature_post_callback() {

	$options = get_option( 'infomedia_inputs' );
	
		$args = array (
					'post_type'				=>	'post',
					'no_found_rows'			=>	true,
					'posts_per_page' 			=>	-1,
					'update_post_term_cache'	=>	false,
					'update_post_meta_cache'	=>	false,
					'orderby'				=>	'menu_order',
					'order'				=>	'ASC'							
					);
					

		
		$krogsquery = new WP_Query ( $args );
		
		$html = '<select id="feature_post" name="infomedia_inputs[feature_post]">';
		
				while( $krogsquery->have_posts() ) : $krogsquery->the_post(); 

				$html .= '<option value="' . get_the_ID() . '"' . selected( $options['feature_post'], get_the_ID(), false) . '>' . get_the_title() . '</option>';
	

			endwhile; 
			
			wp_reset_postdata();  // reset query 
			
		$html .= '</select>';

	
	echo $html;
	
}


/* ------------------------------------------------------------------------ *
 * Setting Callbacks
 * ------------------------------------------------------------------------ */ 

function infomedia_validate_inputs( $input ) {

	// Create our array for storing the validated options
	$output = array();
	
	// Loop through each of the incoming options
	foreach( $input as $key => $value ) {
		
		// Check to see if the current option has a value. If so, process it.
		if( isset( $input[$key] ) ) {
		
			// Strip all HTML and PHP tags and properly handle quoted strings
			$output[$key] = strip_tags( stripslashes( $input[ $key ] ) );
			
		} // end if
		
	} // end foreach
	
	// Return the array processing any additional functions filtered by this action
	return apply_filters( 'infomedia_validate_inputs', $output, $input );

} // end infomedia_validate_inputs