From c922bb20a3e3ea5f9aed6f95ec7c8ca0b70c474d Mon Sep 17 00:00:00 2001
From: Galen Charlton <gmc@esilibrary.com>
Date: Mon, 25 Nov 2013 10:05:21 -0800
Subject: [PATCH] LP#1254816: prevent cases where a Google Book preview is not
 displayed

Due to quirks in how different parts of the Google Books API
processes ISBN searches, it is possible for a Google Books Preview
badge to get displayed, but when the user tries to display the preview,
the embedded preview does not get displayed.

This patch fixes the problem by grabbing the preview link from
the GB volumes search results, which in turn can be fed into the
Embedded Viewer initialization.

An ISBN that can be used to reproduce the problem is 9781937994198.
Before the patch, the badge is displayed but not the preview; after
the patch, both badge and preview should be displayed.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>
---
 Open-ILS/src/templates/opac/parts/ac_google_books.tt2 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Open-ILS/src/templates/opac/parts/ac_google_books.tt2 b/Open-ILS/src/templates/opac/parts/ac_google_books.tt2
index cbec24f1e3..a03bfb9c5b 100644
--- a/Open-ILS/src/templates/opac/parts/ac_google_books.tt2
+++ b/Open-ILS/src/templates/opac/parts/ac_google_books.tt2
@@ -1,5 +1,6 @@
 <script type="text/javascript">
 var GBisbns = Array();
+var GBPreviewLink = '';
 var GBPreviewShowing = false;
 
 /**
@@ -27,6 +28,10 @@ function GBPreviewCallback(GBPBookInfo) {
   }
 
   if ( accessInfo.embeddable ) {
+    GPPreviewLink = GBPBookInfo.items[0].volumeInfo.previewLink;
+    if ( !GPPreviewLink) {
+        return;
+    }
     /* Add a button below the book cover image to load the preview. */
     var GBPBadge = document.createElement( 'img' );
     GBPBadge.id = 'gbpbadge';
@@ -66,7 +71,7 @@ function GBDisplayPreview(scroll_to_div) {
 
 function GBPViewerLoadCallback() {
   var GBPViewer = new google.books.DefaultViewer(dojo.byId('rdetail_preview_div'));
-  GBPViewer.load('ISBN:' + GBisbns[0]);
+  GBPViewer.load(GPPreviewLink);
   GBPViewer.resize();
   var GBPBadgelink = dojo.byId('gbpbadge_link');
   GBPBadgelink.href = 'javascript:GBShowHidePreview(true);';
-- 
2.11.0