From d7ef743766389a85111f9061cce17687ba5326a1 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 3dbb5f988e..2af92b9645 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