Load updated Web UI files after server upgrade

Issue:
* There was no caching policy specified.
* -> Browsers use their own default policy.
* -> After upgrade, some Web UI files might have been actualized some not.
* -> With schema change may result into weird bugs in Web UI

Solution considerations:

1. Detect server version change and hard-reload at runtime
Detection is easy. Problem is the reload. Obvious candidate 'window.location.reload(true)' works in Firefox but not in Chrome because expected behavior when parameter is used is not in standard and therefore Chromium/WebKit authors did not implement it.

2. Application Cache
HTML 5 technology which lets web apps to run offline. Besides weird issues with event handlers which I encountered, this would be an ideal candidate. Simple change of manifest file would lead to reload of all files (requires reload of page to used the new files).

Showstopper was usage with untrusted certificate. If user did not add exception for the cert or its CA and would visit the page for a second time, all AJAX calls would fail.

3. Set Expires to now() for everything
Web UI rarely changes so this is an overkill. Setting it to different value is not a solution either. We can't predict when the upgrade will happen and when new Web UI will be needed.

Solution:
* Implemented a mini loader which loads basic resources. Dojo loader takes action after Dojo is loaded.
* The loader adds a version parameter (?v=__NUM_VERSION__) to all requests.
* Version is defined in the loader. It's set to current in `make version-update`.
* All static pages use this loader to fetch their resources.
* Version is also passed to dojo loader as cache-bust for the same effect.
* Expire header was set to 'access time plus 1 year' for /ui folder. Exceptions are HTML files and loader (set to immediate expiration).

Possible issues:
* Images are cached but not requested with version param.
  * Images with version and without are considered different
  * -> We would have to attach version to all URIs - in CSS and in JS. But we should avoid changing jQuery UI CSS.
  * Proposed solution is to change image name when changing image. Image change is done rarely.
* Version is set by build and therefore updated just on server update. It might cause trouble with different update schedule of plugins.
  * No action taken to address this issue yet.
  * We might leave it on plugin devs (own .conf in /etc/httpd/conf.d/)
  * or set expires to now for all plugins
* running `make version-update` is required in order to use static version of UI for testing

https://fedorahosted.org/freeipa/ticket/3798

14 files changed, 243 insertions, 105 deletions

diff --git a/.gitignore b/.gitignore
index 5252dad1b..96c151a19 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,10 +54,10 @@ install/missing
 install/stamp-h1
 install/po/test.po
 install/po/test_locale/xh_ZA/LC_MESSAGES/ipa.mo
-install/ui/test/results
 install/ui/release
 install/ui/src/dojo
 install/ui/src/build
+install/ui/src/libs/loader.js
 install/ui/src/plugins
 ipa-client/COPYING
 ipa-client/ChangeLog
diff --git a/Makefile b/Makefile
index 428f19b1a..0664ddd8e 100644
--- a/Makefile
+++ b/Makefile
@@ -116,13 +116,14 @@ version-update: release-update
 		freeipa.spec.in > freeipa.spec
 	sed -e s/__VERSION__/$(IPA_VERSION)/ version.m4.in \
 		> version.m4
-
 	sed -e s/__VERSION__/$(IPA_VERSION)/ ipapython/setup.py.in \
 		> ipapython/setup.py
 	sed -e s/__VERSION__/$(IPA_VERSION)/ ipapython/version.py.in \
 		> ipapython/version.py
 	sed -e s/__VERSION__/$(IPA_VERSION)/ ipatests/setup.py.in \
 		> ipatests/setup.py
+	sed -e s/__NUM_VERSION__/$(IPA_NUM_VERSION)/ install/ui/src/libs/loader.js.in \
+		> install/ui/src/libs/loader.js
 	perl -pi -e "s:__NUM_VERSION__:$(IPA_NUM_VERSION):" ipapython/version.py
 	perl -pi -e "s:__API_VERSION__:$(IPA_API_VERSION_MAJOR).$(IPA_API_VERSION_MINOR):" ipapython/version.py
 	touch -r ipapython/version.py.in ipapython/version.py
diff --git a/install/conf/ipa.conf b/install/conf/ipa.conf
index 1a33f6287..f185f5146 100644
--- a/install/conf/ipa.conf
+++ b/install/conf/ipa.conf
@@ -1,5 +1,5 @@
 #
-# VERSION 13 - DO NOT REMOVE THIS LINE
+# VERSION 14 - DO NOT REMOVE THIS LINE
 #
 # This file may be overwritten on upgrades.
 #
@@ -114,6 +114,8 @@ Alias /ipa/config "/usr/share/ipa/html"
   AllowOverride None
   Satisfy Any
   Allow from all
+  ExpiresActive On
+  ExpiresDefault "access plus 0 seconds"
 </Directory>
 
 
@@ -135,6 +137,11 @@ Alias /ipa/ui "/usr/share/ipa/ui"
   AllowOverride None
   Satisfy Any
   Allow from all
+  ExpiresActive On
+  ExpiresDefault "access plus 1 year"
+  <FilesMatch "(index.html|loader.js|login.html|reset_password.html)">
+        ExpiresDefault "access plus 0 seconds"
+  </FilesMatch>
 </Directory>
 
 #  Simple wsgi scripts required by ui
diff --git a/install/html/browserconfig.html b/install/html/browserconfig.html
index a7784f75b..d867a1941 100644
--- a/install/html/browserconfig.html
+++ b/install/html/browserconfig.html
@@ -3,16 +3,25 @@
 <head>
     <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
-
-    <link rel="stylesheet" type="text/css" href="../ui/jquery-ui.css" />
-    <link rel="stylesheet" type="text/css" href="../ui/ipa.css" />
-    <link rel="stylesheet" type="text/css" href="ipa_error.css" />
-
-    <script type="text/javascript" src="../ui/js/libs/jquery.js"></script>
-    <script type="text/javascript" src="../ui/js/libs/jquery-ui.js"></script>
-    <script type="text/javascript" src="krb.js"></script>
-    <script type="text/javascript" src="ffconfig.js"></script>
-    <script type="text/javascript"  src="ffconfig_page.js"></script>
+    <script type="text/javascript" src="../ui/js/libs/loader.js"></script>
+    <script type="text/javascript">
+        (function() {
+            var styles = [
+                '../ui/jquery-ui.css',
+                '../ui/ipa.css',
+                'ipa_error.css'
+            ];
+            var scripts = [
+                '../ui/js/libs/jquery.js',
+                '../ui/js/libs/jquery-ui.js',
+                'krb.js',
+                'ffconfig.js',
+                'ffconfig_page.js'
+            ];
+            ipa_loader.scripts(scripts);
+            ipa_loader.styles(styles);
+        })();
+    </script>
 </head>
 
 <body class="info-page">
diff --git a/install/html/ssbrowser.html b/install/html/ssbrowser.html
index 72fd573cf..896cabcec 100644
--- a/install/html/ssbrowser.html
+++ b/install/html/ssbrowser.html
@@ -3,30 +3,41 @@
 <head>
 <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
-
-    <link rel="stylesheet" type="text/css" href="../ui/jquery-ui.css" />
-    <link rel="stylesheet" type="text/css" href="../ui/ipa.css" />
-    <link rel="stylesheet" type="text/css" href="ipa_error.css" />
-
-    <script type="text/javascript" src="../ui/js/libs/jquery.js"></script>
-    <script type="text/javascript" src="krb.js"></script>
+    <script type="text/javascript" src="../ui/js/libs/loader.js"></script>
     <script type="text/javascript">
-        $(document).ready(function() {
-            var domain = '.' + (IPA_DOMAIN || 'example.com');
-            $('.example-domain').text(domain);
+        (function() {
+            function loaded() {
+                $(document).ready(function() {
+                    var domain = '.' + (IPA_DOMAIN || 'example.com');
+                    $('.example-domain').text(domain);
 
-            if ($.browser.mozilla) {
-                var ff_config = $("#configurefirefox");
-                var obj = $('<object/>', {
-                    type: 'text/html',
-                    'class': 'browser-config'
+                    if ($.browser.mozilla) {
+                        var ff_config = $("#configurefirefox");
+                        var obj = $('<object/>', {
+                            type: 'text/html',
+                            'class': 'browser-config'
+                        });
+                        obj.prop('data', 'jar:/ipa/errors/configure.jar!/preferences.html');
+                        obj.appendTo(ff_config);
+                        ff_config.show();
+                    }
                 });
-                obj.prop('data', 'jar:/ipa/errors/configure.jar!/preferences.html');
-                obj.appendTo(ff_config);
-                ff_config.show();
             }
-        });
+
+            var styles = [
+                '../ui/jquery-ui.css',
+                '../ui/ipa.css',
+                'ipa_error.css'
+            ];
+            var scripts = [
+                '../ui/js/libs/jquery.js',
+                'krb.js'
+            ];
+            ipa_loader.scripts(scripts, loaded);
+            ipa_loader.styles(styles);
+        })();
     </script>
+
 </head>
 
 <body class="info-page">
diff --git a/install/html/unauthorized.html b/install/html/unauthorized.html
index 0fac88b98..5c5ed7e98 100644
--- a/install/html/unauthorized.html
+++ b/install/html/unauthorized.html
@@ -3,12 +3,16 @@
 <head>
     <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
-
-    <script type="text/javascript" src="../ui/js/libs/jquery.js"></script>
-
-    <link rel="stylesheet" type="text/css" href="../ui/jquery-ui.css" />
-    <link rel="stylesheet" type="text/css" href="../ui/ipa.css" />
-    <link rel="stylesheet" type="text/css" href="ipa_error.css" />
+    <script type="text/javascript" src="../ui/js/libs/loader.js"></script>
+    <script type="text/javascript">
+        (function() {
+            var styles = [
+                '../ui/ipa.css',
+                'ipa_error.css'
+            ];
+            ipa_loader.styles(styles);
+        })();
+    </script>
 </head>
 
 <body class="info-page">
diff --git a/install/ui/Makefile.am b/install/ui/Makefile.am
index 77aab17a6..94bedace3 100644
--- a/install/ui/Makefile.am
+++ b/install/ui/Makefile.am
@@ -10,7 +10,6 @@ SUBDIRS =  				\
 
 appdir = $(IPA_DATA_DIR)/ui
 app_DATA =				\
-	config.js			\
 	favicon.ico			\
 	index.html 			\
 	jquery-ui.css			\
diff --git a/install/ui/config.js b/install/ui/config.js
deleted file mode 100644
index e984676f3..000000000
--- a/install/ui/config.js
+++ /dev/null
@@ -1,39 +0,0 @@
-/*  Authors:
- *    Petr Vobornik <pvoborni@redhat.com>
- *
- * Copyright (C) 2012 Red Hat
- * see file 'COPYING' for use and warranty information
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-var dojoConfig= {
-    baseUrl: "js",
-    has: {
-        'dojo-firebug': false,
-        'dojo-debug-messages': true
-    },
-    parseOnLoad: false,
-    async: true,
-    packages: [
-        {
-            name:'dojo',
-            location:'dojo'
-        },
-        {
-            name: 'freeipa',
-            location: 'freeipa'
-        }
-    ]
-};
\ No newline at end of file
diff --git a/install/ui/index.html b/install/ui/index.html
index 75ff82997..4be834076 100644
--- a/install/ui/index.html
+++ b/install/ui/index.html
@@ -1,32 +1,62 @@
 <!DOCTYPE html>
 <html>
 <head>
-<meta charset="utf-8">
+    <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
 
-
-    <link rel="stylesheet" type="text/css" href="jquery-ui.css" />
-    <link rel="stylesheet" type="text/css" href="ipa.css" />
-    <!--ie only stylesheet -->
     <!--[if IE]>
-    <link rel="stylesheet" type="text/css" href="ie.css" />
+    <meta id="ie-detector">
     <![endif]-->
-    <link rel="icon" type="image/ico" href="favicon.ico">
 
-    <script type="text/javascript" src="js/libs/json2.js"></script>
-    <script type="text/javascript" src="js/libs/jquery.js"></script>
-    <script type="text/javascript" src="js/libs/jquery-ui.js"></script>
-    <script type="text/javascript" src="js/libs/jquery.ordered-map.js"></script>
-    <script type="text/javascript" src="js/libs/browser.js"></script>
+    <script type="text/javascript" src="js/libs/loader.js"></script>
+    <script type="text/javascript">
+
+        var dojoConfig = {
+            baseUrl: "js",
+            has: {
+                'dojo-firebug': false,
+                'dojo-debug-messages': true
+            },
+            parseOnLoad: false,
+            async: true,
+            packages: [
+                {
+                    name:'dojo',
+                    location:'dojo'
+                },
+                {
+                    name: 'freeipa',
+                    location: 'freeipa'
+                }
+            ],
+            cacheBust: ipa_loader.num_version || ""
+        };
 
+        (function() {
+            var ie = !!document.getElementById('ie-detector');
+            var styles = ['jquery-ui.css', 'ipa.css'];
+            if (ie) styles.push('ie.css');
+            var icons = ['favicon.ico'];
+            var scripts = [
+                'js/libs/json2.js',
+                'js/libs/jquery.js',
+                'js/libs/jquery-ui.js',
+                'js/libs/jquery.ordered-map.js',
+                'js/libs/browser.js',
+                'js/dojo/dojo.js'
+            ];
+            ipa_loader.scripts(scripts, function() {
+                require(['freeipa/app'], function(app){ app.run(); });
+            });
+            ipa_loader.styles(styles);
+            ipa_loader.icons(icons);
 
-    <script type="text/javascript" src="config.js"></script>
-    <script type="text/javascript" src="js/dojo/dojo.js"></script>
-    <script type="text/javascript">
-        require(['freeipa/app'], function(app){ app.run(); });
+        })();
     </script>
 </head>
 
-<body></body>
+<body>
+    <noscript>This application requires JavaScript enabled.</noscript>
+</body>
 
 </html>
\ No newline at end of file
diff --git a/install/ui/jsl.conf b/install/ui/jsl.conf
index e9e3ecc5e..7c3be5864 100644
--- a/install/ui/jsl.conf
+++ b/install/ui/jsl.conf
@@ -120,6 +120,7 @@
 +define jQuery
 +define define
 +define require
++define ipa_loader
 
 ### Files
 # Specify which files to lint
@@ -128,6 +129,7 @@
 # or "+process Folder\Path\*.htm".
 #
 
++process index.html
 +process src/libs/browser.js
 +process src/libs/jquery.ordered-map.js
 +process src/freeipa/*.js
diff --git a/install/ui/login.html b/install/ui/login.html
index 5545e8834..f3a0dd37b 100644
--- a/install/ui/login.html
+++ b/install/ui/login.html
@@ -3,11 +3,16 @@
 <head>
     <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
-
-    <link rel="stylesheet" type="text/css" href="ipa.css" />
-
-    <script type="text/javascript" src="js/libs/jquery.js"></script>
-    <script type="text/javascript" src="login.js"></script>
+    <script type="text/javascript" src="js/libs/loader.js"></script>
+    <script type="text/javascript">
+        (function() {
+            ipa_loader.styles(['ipa.css']);
+            ipa_loader.scripts([
+                'js/libs/jquery.js',
+                'login.js'
+            ]);
+        })();
+    </script>
 </head>
 
 <body class="info-page login-page">
diff --git a/install/ui/reset_password.html b/install/ui/reset_password.html
index 4dbbb7aac..560e8a5e4 100644
--- a/install/ui/reset_password.html
+++ b/install/ui/reset_password.html
@@ -3,11 +3,16 @@
 <head>
     <meta charset="utf-8">
     <title>IPA: Identity Policy Audit</title>
-
-    <link rel="stylesheet" type="text/css" href="ipa.css" />
-
-    <script type="text/javascript" src="js/libs/jquery.js"></script>
-    <script type="text/javascript" src="reset_password.js"></script>
+    <script type="text/javascript" src="js/libs/loader.js"></script>
+    <script type="text/javascript">
+        (function() {
+            ipa_loader.styles(['ipa.css']);
+            ipa_loader.scripts([
+                'js/libs/jquery.js',
+                'reset_password.js'
+            ]);
+        })();
+    </script>
 </head>
 
 <body class="info-page login-page">
diff --git a/install/ui/src/libs/Makefile.am b/install/ui/src/libs/Makefile.am
index 807b9d8d3..6991e474e 100644
--- a/install/ui/src/libs/Makefile.am
+++ b/install/ui/src/libs/Makefile.am
@@ -7,6 +7,7 @@ app_DATA =				\
 	jquery.ordered-map.js 		\
 	jquery-ui.js 			\
 	json2.js 			\
+	loader.js 			\
 	$(NULL)
 
 EXTRA_DIST =                            \
diff --git a/install/ui/src/libs/loader.js.in b/install/ui/src/libs/loader.js.in
new file mode 100644
index 000000000..134e061e7
--- /dev/null
+++ b/install/ui/src/libs/loader.js.in
@@ -0,0 +1,103 @@
+/*  Authors:
+ *    Petr Vobornik <pvoborni@redhat.com>
+ *
+ * Copyright (C) 2013 Red Hat
+ * see file 'COPYING' for use and warranty information
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+(function() {
+
+    var loader = window.ipa_loader = {
+        num_version: '__NUM_VERSION__'
+    };
+
+    var head = document.getElementsByTagName('head')[0];
+
+    function link(path, rel) {
+        rel = rel || 'stylesheet';
+        var el = document.createElement('link');
+        el.setAttribute('rel', rel);
+        el.setAttribute('type', 'text/css');
+        el.setAttribute('href', path);
+        head.appendChild(el);
+    }
+
+    function js(path, callback) {
+        var el = document.createElement('script');
+        el.setAttribute('type', 'text/javascript');
+        el.setAttribute('src', path);
+        var done = false;
+        var onload = function () {
+            if (done) return;
+            done = true;
+            callback();
+        };
+
+        // older ie
+        el.onreadystatechange = function () {
+            if (el.readyState === 'loaded' || el.readyState === 'complete') {
+                el.onreadystatechange = null;
+                onload();
+            }
+        };
+        // others
+        el.onload = onload;
+
+        head.appendChild(el);
+    }
+
+    function synchronous_download(paths, callback) {
+
+        var dl = paths.splice(0, 1)[0];
+        if (dl) {
+            js(dl, function() {
+                synchronous_download(paths, callback);
+            });
+        } else {
+            if (callback) callback();
+        }
+    }
+
+    function version_suffix() {
+        var suffix = '';
+        if (loader.num_version) {
+            suffix = '?v=' + loader.num_version;
+        }
+        return suffix;
+    }
+
+    loader.scripts = function(scripts, callback) {
+        var suffix = version_suffix();
+        var syn_code = [];
+        for (var i=0; i < scripts.length; i++) {
+            syn_code.push(scripts[i]+suffix);
+        }
+        synchronous_download(syn_code, callback);
+    };
+
+    loader.styles = function(styles) {
+        var suffix = version_suffix();
+        for (var i=0; i < styles.length; i++) {
+            link(styles[i] + suffix);
+        }
+    };
+
+    loader.icons = function(icons) {
+        var suffix = version_suffix();
+        for (var i=0; i < icons.length; i++) {
+            link(icons[i] + suffix, 'icon');
+        }
+    };
+})();
\ No newline at end of file