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<?php
/* Function to return current page/post/cat/etc specific title in header - outside wp loop */
function header_title() {
	if (!is_home()) {
		if (is_category()) { $category = get_category( get_query_var( 'cat' ) ); 
			$current_header_title = $category->cat_name; }
		elseif (is_single() || is_page() ) { $current_header_title = the_title(); }
		elseif (is_tag()) { $current_header_title = single_tag_title(); }
		elseif (is_day()) { $current_header_title = "Archive for "; the_time('F jS, Y'); }
		elseif (is_month()) { $current_header_title = "Archive for "; the_time('F, Y'); }
		elseif (is_year()) { $current_header_title = "Archive for "; the_time('Y'); }
		elseif (is_author()) { $current_header_title = "Author Archive"; }
		elseif (isset($_GET['paged']) && !empty($_GET['paged'])) { $current_header_title = "Blog Archives"; }
		elseif (is_search()) { $current_header_title = "Search Results for '" . get_search_query() ."'"; }
	}
	return $current_header_title;
}
?>

get_header() - Includes the header.php template file from your current theme's directory.

wp_link_pages() - Displays page-links for paginated posts (Next page & Previous Page)

edit_post_link() - display link to edit current post from dashboard

Registering Navigation Menu: 
<?php
// This registers wp_nav_menu() in two locations.
	register_nav_menus( array(
		'primary'   => __( 'Top primary menu', 'twentyfourteen' ),
		'secondary' => __( 'Secondary menu in left sidebar', 'twentyfourteen' ),
	) );
?>

get_template_part()
Load a template part (other than header, sidebar, footer) into a template. Makes it easy for a theme to reuse sections of code and an easy way for child themes to replace sections of their parent theme. 
<?php get_template_part( $slug, $name ); ?>
<?php get_template_part( 'loop', 'index' ); // Loads (loop-index.php) ?>
<?php get_template_part( 'nav' );  // Navigation bar (nav.php) ?>
Important Link: https://codex.wordpress.org/Function_Reference/get_template_part
	
Enabling Support for Post Thumbnails:
Themes have to declare their support for post thumbnails (Featured Image) before the interface for assigning these images will appear on the Edit Post and Edit Page screens.
<?php add_theme_support( 'post-thumbnails' );  ?>

set_post_thumbnail_size() - Set the default Featured Image (formerly Post Thumbnail) dimensions. To register additional image sizes for Featured Images use: add_image_size(). 
 <?php set_post_thumbnail_size( $width, $height, $crop ); ?> 
 
 Register a new image size:
<?php add_image_size( 'custom-size', 220, 180, true ); // 220 pixels wide by 180 pixels tall, hard crop mode ?>

Registering a Dynamic WordPress Sidebar:
Registering a sidebar or multiple sidebar is fairly simple stuff. Most common approach is to add the register_sidebar( $args ); function with widgets_init() action hook in your theme functions.php file.

This will create a sidebar named "Main Sidebar":
<?php
	register_sidebar( array(
        'name' => __( 'Main Sidebar', 'theme-slug' ),
        'id' => 'sidebar-1',
        'description' => __( 'Widgets in this area will be shown on all posts and pages.', 'theme-slug' ),
    ) );
?>

Displaying Dynamic Sidebars:
The dynamic_sidebar() function takes a single parameter of $index, which can either be the sidebar’s id or name argument that you have set while registering sidebar.
<?php dynamic_sidebar( 'sidebar-1' ); ?>

<?php
/* more functions here */

?>

<?php
/* 	Starts: To allow shortcodes in sidebar widgets */
add_filter('widget_text', 'do_shortcode');
/* 	Ends: To allow shortcodes in sidebar widgets */


/**
 * Starts: Register widgetized areas for left and sidebar as per Trsy design requirement
 * Using <Div> as a container rather than default <li> 
 */
function Trsy_widgets_init() {
	// Trsy Left Widget Area
	register_sidebar( array(
		'name'          => __( 'Trsy Left Widget Area - Default', 'coraline' ),
		'id'            => 'Trsy-left-area-1',
		'description'   => __( 'The Trsy left widget area', 'coraline' ),
		'before_widget' => '<div id="%1$s" class="widget-container %2$s">',
		'after_widget'  => '</div>',
		'before_title'  => '<h3 class="widget-title">',
		'after_title'   => '</h3>',
	) );
	// Trsy Right Widget Area
	register_sidebar( array(
		'name'          => __( 'Trsy Right Widget Area - Default', 'coraline' ),
		'id'            => 'Trsy-right-area-1',
		'description'   => __( 'The Trsy right widget area', 'coraline' ),
		'before_widget' => '<div id="%1$s" class="widget-container %2$s">',
		'after_widget'  => '</div>',
		'before_title'  => '<h3 class="widget-title">',
		'after_title'   => '</h3>',
	) );
}

add_action( 'widgets_init', 'Trsy_widgets_init' );
/** Ends: Register widgetized areas for left and sidebar as per Trsy design requirement */
?>

<?php
/* 	Starts: Popular Applications Dropdown select menu */
/* 	Creating Select Dropdown Menu of Posts using specific category (Name: Popular Applications) and
	On Select, it will take you to the Option Value URL (getting from custom field)*/
function popular_apps_dropdown( ) {
	$args = array('category_name' => 'applications', 'posts_per_page' => '-1' , 'orderby' => 'title', 'order' => 'ASC' );
	$category_posts = new WP_Query($args);
	if($category_posts->have_posts()) : ?>
		<select onchange="if (this.options[this.selectedIndex].value) window.open(this.options[this.selectedIndex].value,'_blank'); " name="applications" class="styled">
			<option selected="selected" value="">&nbsp;Select application</option>
			<?php
			  while($category_posts->have_posts()) : 
				 $category_posts->the_post();
				 $app_login_link = get_post_meta(get_the_ID(), 'app_login_link', true);
				if (!empty($app_login_link)) {
				/* List application in dropdown only if has login link */
				?>
				<option value="<?php echo $app_login_link; ?>">&nbsp;<?php the_title(); ?></option>
				<?php }
			endwhile; ?>
		</select>
	<?php else: ?>
		  Oops, there are no Apps.
	<?php endif; wp_reset_query();
}
/* Ends: Popular Applications Dropdown select menu */



/* Starts: Custom Menu select Dropdown */
/* Get nav menu items based on https://codex.wordpress.org/Function_Reference/wp_get_nav_menu_items */
function menu_dropdown_fx( $atts ) {
	extract( shortcode_atts( array(
		'title' => '',
		'name' => 'dropdown-menu',
	), $atts ) );

	ob_start();

	$menu_obj = get_term_by( 'name', $name, 'nav_menu' );
	$menu_id = $menu_obj->term_id;
	$menu = wp_get_nav_menu_object($menu_id );
	$menu_items = wp_get_nav_menu_items($menu->term_id); ?>
	<form id="menu_links_form" action="../">
	<!-- <span id="selectapplications" class="select">&nbsp;Please Select</span> -->
	<select name="select_links" class="styled">
	<option selected="selected" value="#">&nbsp;Please Select</option>
			
	<?php
	foreach ( (array) $menu_items as $key => $menu_item ) {
	    $title = $menu_item->title;
	    $url = $menu_item->url;
		echo "<option value=".$menu_item->url.">&nbsp;".$menu_item->title."</option>";
	}
	?>
	<input type="button" value="" onclick="ob=this.form.select_links;window.open(ob.options[ob.selectedIndex].value)">
	</form> 
	<?php
	$output_string=ob_get_contents();
	ob_end_clean();
	return $output_string;
}
add_shortcode( 'menu_dropdown', 'menu_dropdown_fx' );
/* Ends: Custom Menu select Dropdown */

<?php
/* Using WordPress Navigation menu as select dropdown */
/* Get the nav menu based on $menu_name (same as 'theme_location' or 'menu' arg to wp_nav_menu) */
    // This code based on wp_nav_menu's code to get Menu ID from menu slug
function nav_dropdown() {
    $menu_name = 'site-navigation-menu';

    if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $menu_name ] ) ) {
	$menu = wp_get_nav_menu_object( $locations[ $menu_name ] );

	$menu_items = wp_get_nav_menu_items($menu->term_id);

	$menu_list = '<select id="$menu_name" name="applications" class="styled">';

	foreach ( (array) $menu_items as $key => $menu_item ) {
	    $title = $menu_item->title;
	    $url = $menu_item->url;
	    // $menu_list .= '<li><a href="' . $url . '">' . $title . '</a></li>';
	    $menu_list .= '<option value="' . $url . '">' . $title . '</option>';
	}
	echo $menu_list .= '</select>';
    } else {
	echo $menu_list = '<ul><li>Menu "' . $menu_name . '" not defined.</li></ul>';
    }
    // $menu_list now ready to output
}
?>