LP#1685840: Dojoless Google Books Preview as external script

Rather than including the JavaScript inline in each page, load the
JavaScript as a regular external JavaScript file so that browsers
can take advantage of caching, reduce network bandwidth, and reduce the
amount of TT2 processing required. Every little bit helps.

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Ben Shum <ben@evergreener.net>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>

diff --git a/Open-ILS/src/templates/opac/parts/ac_google_books.tt2 b/Open-ILS/src/templates/opac/parts/ac_google_books.tt2
deleted file mode 100644 (file)
index 22f6963..0000000
--- a/Open-ILS/src/templates/opac/parts/ac_google_books.tt2
+++ /dev/null
@@ -1,164 +0,0 @@
-<script>
-;(function () {
-  var GBisbns = [];
-  var GBPBadgelink;
-  var GBPreviewLink = '';
-  var GBPreviewShowing = false;
-  var lang = 'en';
-  if (document.documentElement.lang) {
-    lang = document.documentElement.lang.substr(0,2) || 'en';
-  }
-  var head = document.getElementsByTagName('head')[0];
-
-/**
- * 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) {
-      GBPreviewLink = GBPBookInfo.items[0].volumeInfo.previewLink;
-      if (!GBPreviewLink) {
-        return;
-      }
-      if (document.location.protocol === 'https:') {
-        GBPreviewLink = GBPreviewLink.replace(/^http:/, 'https:');
-      }
-      var gbsrc = '//www.google.com/books/jsapi.js';
-      if (!head.querySelector('script[src="' + gbsrc + '"]')) {
-        var GBjsapi = document.createElement('script');
-        GBjsapi.src = gbsrc;
-        head.appendChild(GBjsapi);
-      }
-    /* 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/' + lang + '/googlebooks/images/gbs_preview_button1.gif';
-      GBPBadge.title = document.getElementById('rdetail_title').innerHTML;
-      GBPBadge.style.border = 0;
-      GBPBadge.style.margin = '0.5em 0 0 0';
-      GBPBadgelink = document.createElement('a');
-      GBPBadgelink.id = 'gbpbadge_link';
-      GBPBadgelink.addEventListener('click', GBDisplayPreview);
-      GBPBadgelink.appendChild(GBPBadge);
-      document.getElementById('rdetail_title_div').appendChild(GBPBadgelink);
-      document.getElementById('gbp_extra').style.display = 'block';
-    }
-  }
-
-  function GBPViewerLoadCallback () {
-    var GBPViewer = new google.books.DefaultViewer(document.getElementById('rdetail_preview_div'));
-    GBPViewer.load(GBPreviewLink);
-    GBPViewer.resize();
-    GBPBadgelink = document.getElementById('gbpbadge_link');
-    GBPBadgelink.removeEventListener('click', GBDisplayPreview);
-    GBPBadgelink.addEventListener('click', GBShowHidePreview);
-  }
-
-/**
- *  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.getElementById('rdetail_preview_div');
-    if (GBPreviewPane === null || typeof GBPreviewPane.loaded === 'undefined' || GBPreviewPane.loaded === 'false') {
-      GBPreviewPane = document.createElement('div');
-      GBPreviewPane.id = 'rdetail_preview_div';
-      GBPreviewPane.style.height = document.documentElement.clientHeight + 'px';
-      GBPreviewPane.style.width = document.documentElement.clientWidth + 'px';
-      GBPreviewPane.style.display = 'block';
-      var GBClear = document.createElement('div');
-      GBClear.style.padding = '1em';
-      document.getElementById('gbp_extra_container').appendChild(GBPreviewPane);
-      document.getElementById('gbp_extra_container').appendChild(GBClear);
-      google.books.load({'language': lang});
-      window.setTimeout(GBPViewerLoadCallback, 750);
-      var extras = document.getElementById('gbp_extra_links').getElementsByTagName('a');
-      for (var i = 0; i < extras.length; i++) {
-        extras[i].addEventListener('click', GBShowHidePreview);
-      }
-      GBPreviewPane.loaded = 'true';
-    }
-    GBShowHidePreview();
-    document.location.hash = '#gbp_extra';
-  }
-
-  function GBShowHidePreview () {
-    if (!GBPreviewShowing) {
-      document.getElementById('gbp_extra_container').style.display = 'inherit';
-      document.getElementById('gbp_arrow_link').style.display = 'none';
-      document.getElementById('gbp_arrow_down_link').style.display = 'inline';
-      GBPreviewShowing = true;
-      document.location.hash = '#gbp_extra';
-    } else { // button can open, but shouldn't close
-      document.getElementById('gbp_extra_container').style.display = 'none';
-      document.getElementById('gbp_arrow_link').style.display = 'inline';
-      document.getElementById('gbp_arrow_down_link').style.display = 'none';
-      GBPreviewShowing = false;
-      document.location.hash = 'rdetail_title';
-    }
-  }
-
-  function GBLoader () {
-    var spans = document.body.querySelectorAll('li.rdetail_isbns span.rdetail_value');
-    for (var i = 0; i < spans.length; i++) {
-      var prop = spans[i].getAttribute('property');
-      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);
-    }
-
-    if (GBisbns.length) {
-      var req = new window.XMLHttpRequest();
-      var qisbn = encodeURIComponent('isbn:' + GBisbns[0]);
-      req.open('GET', 'https://www.googleapis.com/books/v1/volumes?q=' + qisbn + '&prettyPrint=false');
-      if (req.responseType && (req.responseType = 'json')) {
-        req.onload = function (evt) {
-          var result = req.response;
-          if (result) {
-            GBPreviewCallback(result);
-          }
-        }
-      } else {
-      // IE 10/11
-        req.onload = function (evt) {
-          var result = JSON.parse(req.responseText);
-          if (result) {
-            GBPreviewCallback(result);
-          }
-        }
-      }
-      req.send();
-    }
-  };
-
-  // Skips IE9
-  if (window.addEventListener && !window.XDomainRequest) {
-    window.addEventListener('load', GBLoader, false);
-  }
-})()
-</script>

diff --git a/Open-ILS/src/templates/opac/parts/js.tt2 b/Open-ILS/src/templates/opac/parts/js.tt2
index 1deac91..f7fc737 100644 (file)
--- a/Open-ILS/src/templates/opac/parts/js.tt2
+++ b/Open-ILS/src/templates/opac/parts/js.tt2
@@ -59,7 +59,9 @@
     IF CGI.https; url = url.replace('^http:', 'https:'); END; %]
 <script type='text/javascript' id='EIT' src='[% url %]'></script>
 [%- END %]
-[% INCLUDE "opac/parts/ac_google_books.tt2" IF ctx.page == 'record' AND ctx.google_books_preview %]
+[%- IF ctx.page == 'record' AND ctx.google_books_preview %]
+<script src='[% ctx.media_prefix %]/js/ui/default/opac/ac_google_books.js' async defer></script>
+[%- END %]
 [%- IF want_dojo; -%]
 <script type="text/javascript">
      var djConfig = {

diff --git a/Open-ILS/web/js/ui/default/opac/ac_google_books.js b/Open-ILS/web/js/ui/default/opac/ac_google_books.js
new file mode 100644 (file)
index 0000000..6c9aa00
--- /dev/null
+++ b/Open-ILS/web/js/ui/default/opac/ac_google_books.js
@@ -0,0 +1,162 @@
+;(function () {
+  var GBisbns = [];
+  var GBPBadgelink;
+  var GBPreviewLink = '';
+  var GBPreviewShowing = false;
+  var lang = 'en';
+  if (document.documentElement.lang) {
+    lang = document.documentElement.lang.substr(0,2) || 'en';
+  }
+  var head = document.getElementsByTagName('head')[0];
+
+/**
+ * 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) {
+      GBPreviewLink = GBPBookInfo.items[0].volumeInfo.previewLink;
+      if (!GBPreviewLink) {
+        return;
+      }
+      if (document.location.protocol === 'https:') {
+        GBPreviewLink = GBPreviewLink.replace(/^http:/, 'https:');
+      }
+      var gbsrc = '//www.google.com/books/jsapi.js';
+      if (!head.querySelector('script[src="' + gbsrc + '"]')) {
+        var GBjsapi = document.createElement('script');
+        GBjsapi.src = gbsrc;
+        head.appendChild(GBjsapi);
+      }
+    /* 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/' + lang + '/googlebooks/images/gbs_preview_button1.gif';
+      GBPBadge.title = document.getElementById('rdetail_title').innerHTML;
+      GBPBadge.style.border = 0;
+      GBPBadge.style.margin = '0.5em 0 0 0';
+      GBPBadgelink = document.createElement('a');
+      GBPBadgelink.id = 'gbpbadge_link';
+      GBPBadgelink.addEventListener('click', GBDisplayPreview);
+      GBPBadgelink.appendChild(GBPBadge);
+      document.getElementById('rdetail_title_div').appendChild(GBPBadgelink);
+      document.getElementById('gbp_extra').style.display = 'block';
+    }
+  }
+
+  function GBPViewerLoadCallback () {
+    var GBPViewer = new google.books.DefaultViewer(document.getElementById('rdetail_preview_div'));
+    GBPViewer.load(GBPreviewLink);
+    GBPViewer.resize();
+    GBPBadgelink = document.getElementById('gbpbadge_link');
+    GBPBadgelink.removeEventListener('click', GBDisplayPreview);
+    GBPBadgelink.addEventListener('click', GBShowHidePreview);
+  }
+
+/**
+ *  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.getElementById('rdetail_preview_div');
+    if (GBPreviewPane === null || typeof GBPreviewPane.loaded === 'undefined' || GBPreviewPane.loaded === 'false') {
+      GBPreviewPane = document.createElement('div');
+      GBPreviewPane.id = 'rdetail_preview_div';
+      GBPreviewPane.style.height = document.documentElement.clientHeight + 'px';
+      GBPreviewPane.style.width = document.documentElement.clientWidth + 'px';
+      GBPreviewPane.style.display = 'block';
+      var GBClear = document.createElement('div');
+      GBClear.style.padding = '1em';
+      document.getElementById('gbp_extra_container').appendChild(GBPreviewPane);
+      document.getElementById('gbp_extra_container').appendChild(GBClear);
+      google.books.load({'language': lang});
+      window.setTimeout(GBPViewerLoadCallback, 750);
+      var extras = document.getElementById('gbp_extra_links').getElementsByTagName('a');
+      for (var i = 0; i < extras.length; i++) {
+        extras[i].addEventListener('click', GBShowHidePreview);
+      }
+      GBPreviewPane.loaded = 'true';
+    }
+    GBShowHidePreview();
+    document.location.hash = '#gbp_extra';
+  }
+
+  function GBShowHidePreview () {
+    if (!GBPreviewShowing) {
+      document.getElementById('gbp_extra_container').style.display = 'inherit';
+      document.getElementById('gbp_arrow_link').style.display = 'none';
+      document.getElementById('gbp_arrow_down_link').style.display = 'inline';
+      GBPreviewShowing = true;
+      document.location.hash = '#gbp_extra';
+    } else { // button can open, but shouldn't close
+      document.getElementById('gbp_extra_container').style.display = 'none';
+      document.getElementById('gbp_arrow_link').style.display = 'inline';
+      document.getElementById('gbp_arrow_down_link').style.display = 'none';
+      GBPreviewShowing = false;
+      document.location.hash = 'rdetail_title';
+    }
+  }
+
+  function GBLoader () {
+    var spans = document.body.querySelectorAll('li.rdetail_isbns span.rdetail_value');
+    for (var i = 0; i < spans.length; i++) {
+      var prop = spans[i].getAttribute('property');
+      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);
+    }
+
+    if (GBisbns.length) {
+      var req = new window.XMLHttpRequest();
+      var qisbn = encodeURIComponent('isbn:' + GBisbns[0]);
+      req.open('GET', 'https://www.googleapis.com/books/v1/volumes?q=' + qisbn + '&prettyPrint=false');
+      if (req.responseType && (req.responseType = 'json')) {
+        req.onload = function (evt) {
+          var result = req.response;
+          if (result) {
+            GBPreviewCallback(result);
+          }
+        }
+      } else {
+      // IE 10/11
+        req.onload = function (evt) {
+          var result = JSON.parse(req.responseText);
+          if (result) {
+            GBPreviewCallback(result);
+          }
+        }
+      }
+      req.send();
+    }
+  };
+
+  // Skips IE9
+  if (window.addEventListener && !window.XDomainRequest) {
+    window.addEventListener('load', GBLoader, false);
+  }
+})()