Add support for multiple fallback CDN locations

tedpedersen · Oct 3, 2011 · 762539a · 762539a
1 parent 7ccfe56
commit 762539a
Show file tree

Hide file tree

Showing 2 changed files with 32 additions and 21 deletions.
diff --git a/build.xml b/build.xml
@@ -3,8 +3,8 @@
 <project name="PIE" default="build" basedir=".">
 
     <property name="version" value="1.0beta6-SNAPSHOT" />
-    <!--<property name="default_base_url" value="http://cdnjs.cloudflare.com/ajax/libs/css3pie/${version}" />-->
-    <property name="default_base_url" value="http://lojjic.github.com/PIE/files/builds/${version}" />
+    <!-- 'http://cdnjs.cloudflare.com/ajax/libs/css3pie/${version}' -->
+    <property name="default_base_urls" value="['http://lojjic.github.com/PIE/files/builds/${version}']"/>
     <property name="build_dir" value="./build" />
     <property name="src_dir" value="./sources" />
 
@@ -94,7 +94,7 @@
         <replace file="${build_dir}/PIE_uncompressed.htc">
             <replacefilter token="$Version$" value="${version}" />
             <replacefilter token="$JSVariant$" value="_uncompressed" />
-            <replacefilter token="$DefaultBaseUrl$" value="${default_base_url}" />
+            <replacefilter token="$DefaultBaseUrls$" value="${default_base_urls}" />
         </replace>
         <replace file="${build_dir}/PIE_IE678_uncompressed.js" token="$Version$" value="${version}"/>
         <replace file="${build_dir}/PIE_IE9_uncompressed.js" token="$Version$" value="${version}"/>
@@ -125,7 +125,7 @@
         <replace file="${build_dir}/PIE.htc">
             <replacefilter token="$Version$" value="${version}" />
             <replacefilter token="$JSVariant$" value="" />
-            <replacefilter token="$DefaultBaseUrl$" value="${default_base_url}" />
+            <replacefilter token="$DefaultBaseUrls$" value="${default_base_urls}" />
         </replace>
         <replace file="${build_dir}/PIE_IE678.js" token="$Version$" value="${version}"/>
         <replace file="${build_dir}/PIE_IE9.js" token="$Version$" value="${version}"/>

diff --git a/sources/htc_script.js b/sources/htc_script.js
@@ -6,9 +6,9 @@ var el = element,
 if (!PIE && docMode < 10) {
     (function() {
         var queue = {},
-            defaultBaseUrl = '$DefaultBaseUrl$',
+            baseUrls = $DefaultBaseUrls$,
             protocol = doc.location.protocol,
-            baseUrl, script, tester, isIE6;
+            baseUrl, tester, isIE6, i = 0;
 
         // Create stub PIE object
         PIE = window[ 'PIE' ] = {
@@ -30,27 +30,38 @@ if (!PIE && docMode < 10) {
         baseUrl = doc.documentElement.currentStyle.getAttribute( ( isIE6 ? '' : '-' ) + 'pie-base-url' );
         if( baseUrl ) {
             baseUrl = baseUrl.replace(/^"|"$/g, '');
-        } else {
-            baseUrl = ( protocol === 'https:' ? protocol + defaultBaseUrl.replace( /^[^\/]*]/, '' ) : defaultBaseUrl );
+            baseUrls = [ baseUrl ];
         }
-        baseUrl += '/PIE_IE' + ( docMode < 9 ? '678' : '9' ) + '$JSVariant$.js';
 
         // Start loading JS file
-        script = doc.createElement( 'script' );
-        script.async = true;
-        script.onreadystatechange = function() {
-            var rs = script.readyState, id;
-            if ( queue && ( rs === 'complete' || rs === 'loaded' ) ) {
-                for( id in queue ) {
-                    if ( queue.hasOwnProperty( id ) ) {
-                        PIE[ 'attach' ]( queue[ id ] );
+        function tryLoading( baseUrl ) {
+            var script = doc.createElement( 'script' );
+            script.async = true;
+            script.onreadystatechange = function() {
+                var rs = script.readyState, id;
+                if ( queue && ( rs === 'complete' || rs === 'loaded' ) ) {
+                    if ( 'version' in PIE ) {
+                        for( id in queue ) {
+                            if ( queue.hasOwnProperty( id ) ) {
+                                PIE[ 'attach' ]( queue[ id ] );
+                            }
+                        }
+                        queue = 0;
+                    } else {
+                        tryLoading( baseUrls[ ++i ] );
                     }
                 }
-                queue = 0;
+            };
+
+            if ( protocol === 'https:' ) {
+                baseUrl = baseUrl.replace( /^http:/, protocol );
             }
-        };
-        script.src = baseUrl;
-        ( doc.getElementsByTagName( 'head' )[0] || doc.body ).appendChild( script );
+            script.src = baseUrl + '/PIE_IE' + ( docMode < 9 ? '678' : '9' ) + '$JSVariant$.js';
+            ( doc.getElementsByTagName( 'head' )[0] || doc.body ).appendChild( script );
+        }
+
+        tryLoading( baseUrls[ i ] );
+
     })();
 }