add more helper functions

Functions to retrieve term image ID, URL, fallback image ID, URL, and
function to display term/fallback image as post thumbnail on archives.

includes/helper-functions.php

@@ -15,7 +15,7 @@
  *
  * @since  2.1.0
  */
-function display_featured_image_genesis_get_term_image() {
+function display_featured_image_genesis_get_term_image_id() {
 	$taxonomies = get_taxonomies();
 	$args       = array( 'orderby' => 'count', 'order' => 'DESC' );
 	$terms      = wp_get_object_terms( get_the_ID(), $taxonomies, $args );
@@ -33,3 +33,86 @@ function display_featured_image_genesis_get_term_image() {
 	return $image_id;
 
 }
+
+/**
+ * Helper function to get the term image URL.
+ * @param  string $size image size
+ * @return url       URL associated with the term image
+ *
+ * @since  2.1.0
+ */
+function display_featured_image_genesis_get_term_image_url( $size='displayfeaturedimage_backstretch' ) {
+
+	$image_id  = display_featured_image_genesis_get_term_image_id();
+
+	$image_url = wp_get_attachment_image_src( $image_id, $size );
+
+	return $image_url[0];
+
+}
+
+/**
+ * Helper function to get the default image ID.
+ * @return ID ID associated with the fallback/default image
+ *
+ * @since  2.1.0
+ */
+function display_featured_image_genesis_get_default_image_id() {
+
+	$item     = Display_Featured_Image_Genesis_Common::get_image_variables();
+
+	$image_id = Display_Featured_Image_Genesis_Common::get_image_id( $item->fallback );
+
+	return $image_id;
+
+}
+
+/**
+ * Helper function to get the default image URL.
+ * @param  image size $size image size to retrieve
+ * @return URL       URL associated with the term image
+ *
+ * @since  2.1.0
+ */
+function display_featured_image_genesis_get_default_image_url( $size='displayfeaturedimage_backstretch' ) {
+
+	$image_id  = display_featured_image_genesis_get_default_image_id();
+
+	$image_url = wp_get_attachment_image_src( $image_id, $size );
+
+	return $image_url[0];
+
+}
+
+/**
+ * Add term/default image to blog/archive pages.
+ * @return image If a post doesn't have its own thumbnail, you can use this function to add one to archive pages.
+ *
+ * @since  2.1.0
+ */
+function display_featured_image_genesis_add_archive_thumbnails() {
+
+	if ( ! is_home() && ! is_archive() && ! is_page_template( 'page_blog.php' ) ) {
+		return;
+	}
+
+	if ( has_post_thumbnail() ) {
+		return;
+	}
+
+	$size      = genesis_get_option( 'image_size' );
+	$image_url = display_featured_image_genesis_get_term_image_url( $size );
+	if ( empty( $image_url ) ) {
+		$image_url = display_featured_image_genesis_get_default_image_url( $size );
+	}
+
+	if ( empty( $image_url ) ) {
+		return;
+	}
+
+	$permalink = get_the_permalink();
+	$alignment = genesis_get_option( 'image_alignment' );
+	$image     = '<a href="' . esc_url( $permalink ) . '"><img src="' . esc_url( $image_url ) . '" class="' . $alignment . '" /></a>';
+	echo $image;
+
+}