From 6c4c15cf710cae0bb7af2ff79fb768bb4347a54c Mon Sep 17 00:00:00 2001
From: Dan Scott <dscott@laurentian.ca>
Date: Tue, 5 Feb 2013 12:25:24 -0500
Subject: [PATCH] TPAC: Google Books preview loader

Refinements should include checking more than just the first ISBN for
embeddability and passing more identifiers to the preview loader.
Roughly equivalent to what JSPAC had though.

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Ben Shum <bshum@biblio.org>
---
 Open-ILS/src/templates/opac/parts/acjs.tt2         | 96 ++++++++++++++++++++++
 Open-ILS/src/templates/opac/parts/config.tt2       |  5 ++
 .../tpac_google_books_preview.txt                  | 12 +++
 3 files changed, 113 insertions(+)
 create mode 100644 docs/RELEASE_NOTES_NEXT/tpac_google_books_preview.txt

diff --git a/Open-ILS/src/templates/opac/parts/acjs.tt2 b/Open-ILS/src/templates/opac/parts/acjs.tt2
index fe15569e22..33ab4b75c8 100644
--- a/Open-ILS/src/templates/opac/parts/acjs.tt2
+++ b/Open-ILS/src/templates/opac/parts/acjs.tt2
@@ -52,4 +52,100 @@
         END; # IF ident
     %]
 </script>
+[%- IF ctx.google_books_preview -%]
+<script type="text/javascript">
+var GBisbns = Array();
+
+/**
+ *
+ * @param {DOM object} isbn The form element containing the input parameters "isbns"
+ */
+function searchForGBPreview( isbn ) {
+  dojo.require("dojo.io.script");
+  dojo.io.script.get({"url": "https://www.google.com/jsapi"});
+  dojo.io.script.get({"url": "https://www.googleapis.com/books/v1/volumes", "content": { "q": "isbn:" + isbn, "callback": "GBPreviewCallback"}});
+}
+
+/**
+ * This function is the call-back function for the JSON scripts which 
+ * executes a Google book search response.
+ *
+ * @param {JSON} GBPBookInfo is the JSON object pulled from the Google books service.
+ */
+function GBPreviewCallback(GBPBookInfo) {
+  if (GBPBookInfo.totalItems < 1) return;
+
+  var accessInfo = GBPBookInfo.items[0].accessInfo;
+  if ( !accessInfo ) {
+    return;
+  }
+
+  if ( accessInfo.embeddable ) {
+    /* Add a button below the book cover image to load the preview. */
+    var GBPBadge = document.createElement( 'img' );
+    GBPBadge.id = 'gbpbadge';
+    GBPBadge.src = 'https://www.google.com/intl/[% ctx.locale.substr(0,2) %]/googlebooks/images/gbs_preview_button1.gif';
+    GBPBadge.title = dojo.byId('rdetail_title').innerHTML;
+    GBPBadge.style.border = 0;
+    GBPBadge.style.margin = '0.5em 0 0 0';
+    GBPBadgelink = document.createElement('a');
+    GBPBadgelink.href = 'javascript:GBDisplayPreview();';
+    GBPBadgelink.appendChild( GBPBadge );
+    dojo.byId('rdetail_title_div').appendChild( GBPBadgelink );
+  }
+}
+
+/**
+ *  This is called when the user clicks on the 'Preview' link.  We assume
+ *  a preview is available from Google if this link was made visible.
+ */
+function GBDisplayPreview() {
+  var GBPreviewPane = document.createElement('div');
+  GBPreviewPane.id = 'rdetail_preview_div';
+  GBPreviewPane.style.height = '800px';
+  GBPreviewPane.style.width = '600px';
+  GBPreviewPane.style.display = 'block';
+  var GBClear = document.createElement('div');
+  GBClear.style.padding = '1em';
+  dojo.byId('canvas_main').insertBefore(GBPreviewPane, dojo.byId('rdetail_record_details'));
+  dojo.byId('canvas_main').insertBefore(GBClear, dojo.byId('rdetail_record_details'));
+  if (GBPreviewPane.getAttribute('loaded') == null || GBPreviewPane.getAttribute('loaded') == "false" ) {
+     google.load("books", "0", {"callback" : GBPViewerLoadCallback, "language": "[% ctx.locale.substr(0,2) %]"} );
+     GBPreviewPane.setAttribute('loaded', 'true');
+  }
+}
+
+function GBPViewerLoadCallback() {
+  var GBPViewer = new google.books.DefaultViewer(dojo.byId('rdetail_preview_div'));
+  GBPViewer.load('ISBN:' + GBisbns[0]);
+  GBPViewer.resize();
+  dojo.byId('gbpbadge').style.display = 'none';
+}
 
+dojo.addOnLoad(function() {
+  var spans = dojo.query('li.rdetail_isbns span.rdetail_value');
+  for (var i = 0; i < spans.length; i++) {
+    var prop = spans[i].getAttribute('itemprop');
+    if (!prop) {
+      continue;
+    }
+    var isbn = spans[i].textContent || spans[i].innerText;
+    if (!isbn) {
+      continue;
+    }
+    isbn = isbn.toString().replace(/^\s+/,"");
+    var idx = isbn.indexOf(" ");
+    if (idx > -1) {
+      isbn = isbn.substring(0, idx);
+    }
+    isbn = isbn.toString().replace(/-/g,"");
+    if (!isbn) {
+      continue;
+    }
+    GBisbns.push(isbn);
+  }
+
+  searchForGBPreview(GBisbns[0]);
+});
+</script>
+[%- END %]
diff --git a/Open-ILS/src/templates/opac/parts/config.tt2 b/Open-ILS/src/templates/opac/parts/config.tt2
index b0fee8f9a3..e334975330 100644
--- a/Open-ILS/src/templates/opac/parts/config.tt2
+++ b/Open-ILS/src/templates/opac/parts/config.tt2
@@ -128,4 +128,9 @@ search.basic_config = {
     none_label => l("All Formats"),
 };
 
+##############################################################################
+# Show Google Book Previews
+# Set to 1 or 'true' to enable
+ctx.google_books_preview = 0;
+
 %]
diff --git a/docs/RELEASE_NOTES_NEXT/tpac_google_books_preview.txt b/docs/RELEASE_NOTES_NEXT/tpac_google_books_preview.txt
new file mode 100644
index 0000000000..c56582572c
--- /dev/null
+++ b/docs/RELEASE_NOTES_NEXT/tpac_google_books_preview.txt
@@ -0,0 +1,12 @@
+TPAC: Google Books preview
+==========================
+
+Setting `ctx.google_books_preview` to `1` in the TPAC `config.tt2`
+configuration file will cause the TPAC to check to see, as part of the record
+details view, if Google Books has an online preview available. If it does,
+then a preview button will be displayed in the book cover image location.
+If the user then clicks the preview button, the preview will load below the
+title of the book in the record details page.
+
+By default, this functionality is disabled to protect the privacy of users
+who might not want to share their browsing behaviour with Google.
-- 
2.11.0