Merge pull request #468 from cweider/minify-simplify

Minify Simplification

9 files changed, 408 insertions, 260 deletions

diff --git a/node/server.js b/node/server.js
index f254c2ca..8b0ab2f5 100644
--- a/node/server.js
+++ b/node/server.js
@@ -31,6 +31,8 @@ var async = require('async');
 var express = require('express');
 var path = require('path');
 var minify = require('./utils/Minify');
+var CachingMiddleware = require('./utils/caching_middleware');
+var Yajsml = require('yajsml');
 var formidable = require('formidable');
 var apiHandler;
 var exportHandler;
@@ -61,8 +63,7 @@ console.log("Report bugs at https://github.com/Pita/etherpad-lite/issues")
 
 var serverName = "Etherpad-Lite " + version + " (http://j.mp/ep-lite)";
 
-//cache 6 hours
-exports.maxAge = 1000*60*60*6;
+exports.maxAge = settings.maxAge;
 
 //set loglevel
 log4js.setGlobalLogLevel(settings.loglevel);
@@ -141,21 +142,26 @@ async.waterfall([
       gracefulShutdown();
     });
     
-    //serve static files
-    app.get('/static/js/require-kernel.js', function (req, res, next) {
-      res.header("Content-Type","application/javascript; charset: utf-8");
-      res.write(minify.requireDefinition());
-      res.end();
-    });
-    app.get('/static/*', function(req, res)
-    { 
-      var filePath = path.normalize(__dirname + "/.." +
-                                    req.url.replace(/\.\./g, '').split("?")[0]);
-      res.sendfile(filePath, { maxAge: exports.maxAge });
+    // Cache both minified and static.
+    var assetCache = new CachingMiddleware;
+    app.all('/(minified|static)/*', assetCache.handle);
+
+    // Minify will serve static files compressed (minify enabled). It also has
+    // file-specific hacks for ace/require-kernel/etc.
+    app.all('/static/:filename(*)', minify.minify);
+
+    // Setup middleware that will package JavaScript files served by minify for
+    // CommonJS loader on the client-side.
+    var jsServer = new (Yajsml.Server)({
+      rootPath: 'minified/'
+    , rootURI: 'http://' + settings.ip + ":" + settings.port + '/static/js/'
     });
-    
-    //serve minified files
-    app.get('/minified/:filename', minify.minifyJS);
+    var StaticAssociator = Yajsml.associators.StaticAssociator;
+    var associations =
+      Yajsml.associators.associationsForSimpleMapping(minify.tar);
+    var associator = new StaticAssociator(associations);
+    jsServer.setAssociator(associator);
+    app.use(jsServer);
     
     //checks for padAccess
     function hasPadAccess(req, res, callback)
diff --git a/node/utils/Minify.js b/node/utils/Minify.js
index 859ee07a..3d61eeb8 100644
--- a/node/utils/Minify.js
+++ b/node/utils/Minify.js
@@ -27,301 +27,259 @@ var cleanCSS = require('clean-css');
 var jsp = require("uglify-js").parser;
 var pro = require("uglify-js").uglify;
 var path = require('path');
-var Buffer = require('buffer').Buffer;
-var zlib = require('zlib');
 var RequireKernel = require('require-kernel');
 var server = require('../server');
-var os = require('os');
 
-var ROOT_DIR = path.normalize(__dirname + "/../" );
-var JS_DIR = ROOT_DIR + '../static/js/';
-var CSS_DIR = ROOT_DIR + '../static/css/';
-var CACHE_DIR = ROOT_DIR + '../var/';
+var ROOT_DIR = path.normalize(__dirname + "/../../static/");
 var TAR_PATH = path.join(__dirname, 'tar.json');
 var tar = JSON.parse(fs.readFileSync(TAR_PATH, 'utf8'));
 
+// Rewrite tar to include modules with no extensions and proper rooted paths.
+exports.tar = {};
+for (var key in tar) {
+  exports.tar['/' + key] =
+    tar[key].map(function (p) {return '/' + p}).concat(
+      tar[key].map(function (p) {return '/' + p.replace(/\.js$/, '')})
+    );
+}
+
 /**
  * creates the minifed javascript for the given minified name
  * @param req the Express request
  * @param res the Express response
  */
-exports.minifyJS = function(req, res, next)
+exports.minify = function(req, res, next)
 {
-  var jsFilename = req.params['filename'];
-  
-  //choose the js files we need
-  var jsFiles = undefined;
-  if (Object.prototype.hasOwnProperty.call(tar, jsFilename)) {
-    jsFiles = tar[jsFilename];
-    _handle(req, res, jsFilename, jsFiles)
+  var filename = req.params['filename'];
+
+  // No relative paths, especially if they may go up the file hierarchy.
+  filename = path.normalize(path.join(ROOT_DIR, filename));
+  if (filename.indexOf(ROOT_DIR) == 0) {
+    filename = filename.slice(ROOT_DIR.length);
   } else {
-    // Not in tar list, but try anyways, if it fails, pass to `next`.
-    jsFiles = [jsFilename];
-    fs.stat(JS_DIR + jsFilename, function (error, stats) {
-      if (error || !stats.isFile()) {
-        next();
-      } else {
-        _handle(req, res, jsFilename, jsFiles);
-      }
-    });
+    res.writeHead(404, {});
+    res.end();
+    return; 
   }
-}
 
-function _handle(req, res, jsFilename, jsFiles) {
-  res.header("Content-Type","text/javascript");
-  
-  //minifying is enabled
-  if(settings.minify)
-  {
-    var result = undefined;
-    var latestModification = 0;
-    
-    async.series([
-      //find out the highest modification date
-      function(callback)
-      {        
-        var folders2check = [CSS_DIR, JS_DIR];
-        
-        //go trough this two folders
-        async.forEach(folders2check, function(path, callback)
-        {
-          //read the files in the folder
-          fs.readdir(path, function(err, files)
-          {
-            if(ERR(err, callback)) return;
-            
-            //we wanna check the directory itself for changes too
-            files.push(".");
-            
-            //go trough all files in this folder
-            async.forEach(files, function(filename, callback) 
-            {
-              //get the stat data of this file
-              fs.stat(path + "/" + filename, function(err, stats)
-              {
-                if(ERR(err, callback)) return;
-              
-                //get the modification time
-                var modificationTime = stats.mtime.getTime();
-              
-                //compare the modification time to the highest found
-                if(modificationTime > latestModification)
-                {
-                  latestModification = modificationTime;
-                }
-                
-                callback();
-              });
-            }, callback);
-          });
-        }, callback);
-      },
-      function(callback)
-      {
-        //check the modification time of the minified js
-        fs.stat(CACHE_DIR + "/minified_" + jsFilename, function(err, stats)
-        {
-          if(err && err.code != "ENOENT")
-          {
-            ERR(err, callback);
-            return;
-          }
-        
-          //there is no minfied file or there new changes since this file was generated, so continue generating this file
-          if((err && err.code == "ENOENT") || stats.mtime.getTime() < latestModification)
-          {
-            callback();
-          }
-          //the minified file is still up to date, stop minifying
-          else
-          {
-            callback("stop");
-          }
-        });
-      }, 
-      //load all js files
-      function (callback)
-      {
-        var values = [];
-        tarCode(
-          jsFiles
-        , function (content) {values.push(content)}
-        , function (err) {
-          if(ERR(err)) return;
+  // What content type should this be?
+  // TODO: This should use a MIME module.
+  var contentType;
+  if (filename.match(/\.js$/)) {
+    contentType = "text/javascript";
+  } else if (filename.match(/\.css$/)) {
+    contentType = "text/css";
+  } else if (filename.match(/\.html$/)) {
+    contentType = "text/html";
+  } else if (filename.match(/\.txt$/)) {
+    contentType = "text/plain";
+  } else if (filename.match(/\.png$/)) {
+    contentType = "image/png";
+  } else if (filename.match(/\.gif$/)) {
+    contentType = "image/gif";
+  } else if (filename.match(/\.ico$/)) {
+    contentType = "image/x-icon";
+  } else {
+    contentType = "application/octet-stream";
+  }
 
-          result = values.join('');
-          callback();
-        });
-      },
-      //put all together and write it into a file
-      function(callback)
-      {
-        async.parallel([
-          //write the results plain in a file
-          function(callback)
-          {
-            fs.writeFile(CACHE_DIR + "minified_" + jsFilename, result, "utf8", callback);
-          },
-          //write the results compressed in a file
-          function(callback)
-          {
-            zlib.gzip(result, function(err, compressedResult){
-              //weird gzip bug that returns 0 instead of null if everything is ok
-              err = err === 0 ? null : err;
-            
-              if(ERR(err, callback)) return;
-              
-              fs.writeFile(CACHE_DIR + "minified_" + jsFilename + ".gz", compressedResult, callback);
-            });
-          }
-        ],callback);
+  statFile(filename, function (error, date, exists) {
+    if (date) {
+      date = new Date(date);
+      res.setHeader('last-modified', date.toUTCString());
+      res.setHeader('date', (new Date()).toUTCString());
+      if (server.maxAge) {
+        var expiresDate = new Date((new Date()).getTime()+server.maxAge*1000);
+        res.setHeader('expires', expiresDate.toUTCString());
+        res.setHeader('cache-control', 'max-age=' + server.maxAge);
       }
-    ], function(err)
-    {
-      if(err && err != "stop")
-      {
-        if(ERR(err)) return;
-      }
-      
-      //check if gzip is supported by this browser
-      var gzipSupport = req.header('Accept-Encoding', '').indexOf('gzip') != -1;
-      
-      var pathStr;
-      if(gzipSupport && os.type().indexOf("Windows") == -1)
-      {
-        pathStr = path.normalize(CACHE_DIR + "minified_" + jsFilename + ".gz");
-        res.header('Content-Encoding', 'gzip');
-      }
-      else
-      {
-        pathStr = path.normalize(CACHE_DIR + "minified_" + jsFilename );
-      }
-      
-      res.sendfile(pathStr, { maxAge: server.maxAge });
-    })
-  }
-  //minifying is disabled, so put the files together in one file
-  else
-  {
-    tarCode(
-      jsFiles
-    , function (content) {res.write(content)}
-    , function (err) {
-      if(ERR(err)) return;
+    }
+
+    if (error) {
+      res.writeHead(500, {});
       res.end();
-    });
-  }
+    } else if (!exists) {
+      res.writeHead(404, {});
+      res.end();
+    } else if (new Date(req.headers['if-modified-since']) >= date) {
+      res.writeHead(304, {});
+      res.end();
+    } else {
+      if (req.method == 'HEAD') {
+        res.header("Content-Type", contentType);
+        res.writeHead(200, {});
+        res.end();
+      } else if (req.method == 'GET') {
+        getFileCompressed(filename, contentType, function (error, content) {
+          if(ERR(error)) return;
+          res.header("Content-Type", contentType);
+          res.writeHead(200, {});
+          res.write(content);
+          res.end();
+        });
+      } else {
+        res.writeHead(405, {'allow': 'HEAD, GET'});
+        res.end();
+      }
+    }
+  });
 }
 
 // find all includes in ace.js and embed them.
 function getAceFile(callback) {
-  fs.readFile(JS_DIR + 'ace.js', "utf8", function(err, data) {
+  fs.readFile(ROOT_DIR + 'js/ace.js', "utf8", function(err, data) {
     if(ERR(err, callback)) return;
 
     // Find all includes in ace.js and embed them
-    var founds = data.match(/\$\$INCLUDE_[a-zA-Z_]+\([a-zA-Z0-9.\/_"-]+\)/gi);
+    var founds = data.match(/\$\$INCLUDE_[a-zA-Z_]+\("[^"]*"\)/gi);
     if (!settings.minify) {
       founds = [];
     }
+    // Always include the require kernel.
     founds.push('$$INCLUDE_JS("../static/js/require-kernel.js")');
 
     data += ';\n';
     data += 'Ace2Editor.EMBEDED = Ace2Editor.EMBEDED || {};\n';
 
-    //go trough all includes
+    // Request the contents of the included file on the server-side and write
+    // them into the file.
     async.forEach(founds, function (item, callback) {
       var filename = item.match(/"([^"]*)"/)[1];
-      var type = item.match(/INCLUDE_([A-Z]+)/)[1];
-      var shortFilename = (filename.match(/^..\/static\/js\/(.*)$/, '')||[])[1];
+      var request = require('request');
+
+      var baseURI = 'http://' + settings.ip + ":" + settings.port
 
-      //read the included files
-      if (shortFilename) {
-        if (shortFilename == 'require-kernel.js') {
-          // the kernel isn’t actually on the file system.
-          handleEmbed(null, requireDefinition());
+      request(baseURI + path.normalize(path.join('/static/', filename)), function (error, response, body) {
+        if (!error && response.statusCode == 200) {
+          data += 'Ace2Editor.EMBEDED[' + JSON.stringify(filename) + '] = '
+              + JSON.stringify(body || '') + ';\n';
         } else {
-          var contents = '';
-          tarCode(tar[shortFilename] || shortFilename
-          , function (content) {
-              contents += content;
-            }
-          , function () {
-              handleEmbed(null, contents);
+          // Silence?
+        }
+        callback();
+      });
+    }, function(error) {
+      callback(error, data);
+    });
+  });
+}
+
+// Check for the existance of the file and get the last modification date.
+function statFile(filename, callback) {
+  if (filename == 'js/ace.js') {
+    // Sometimes static assets are inlined into this file, so we have to stat
+    // everything.
+    lastModifiedDateOfEverything(function (error, date) {
+      callback(error, date, !error);
+    });
+  } else if (filename == 'js/require-kernel.js') {
+    callback(null, requireLastModified(), true);
+  } else {
+    fs.stat(ROOT_DIR + filename, function (error, stats) {
+      if (error) {
+        if (error.code == "ENOENT") {
+          // Stat the directory instead.
+          fs.stat(path.dirname(ROOT_DIR + filename), function (error, stats) {
+            if (error) {
+              if (error.code == "ENOENT") {
+                callback(null, null, false);
+              } else {
+                callback(error);
+              }
+            } else {
+              callback(null, stats.mtime.getTime(), false);
             }
-          );
+          });
+        } else {
+          callback(error);
         }
       } else {
-        fs.readFile(ROOT_DIR + filename, "utf8", handleEmbed);
+        callback(null, stats.mtime.getTime(), true);
       }
+    });
+  }
+}
+function lastModifiedDateOfEverything(callback) {
+  var folders2check = [ROOT_DIR + 'js/', ROOT_DIR + 'css/'];
+  var latestModification = 0;
+  //go trough this two folders
+  async.forEach(folders2check, function(path, callback)
+  {
+    //read the files in the folder
+    fs.readdir(path, function(err, files)
+    {
+      if(ERR(err, callback)) return;
 
-      function handleEmbed(error, data_) {
-        if (error) {
-          return; // Don't bother to include it.
-        }
-        if (settings.minify) {
-          if (type == "JS") {
-            try {
-              data_ = compressJS([data_]);
-            } catch (e) {
-              // Ignore, include uncompresseed, which will break in browser.
-            }
-          } else {
-            data_ = compressCSS([data_]);
+      //we wanna check the directory itself for changes too
+      files.push(".");
+
+      //go trough all files in this folder
+      async.forEach(files, function(filename, callback)
+      {
+        //get the stat data of this file
+        fs.stat(path + "/" + filename, function(err, stats)
+        {
+          if(ERR(err, callback)) return;
+
+          //get the modification time
+          var modificationTime = stats.mtime.getTime();
+
+          //compare the modification time to the highest found
+          if(modificationTime > latestModification)
+          {
+            latestModification = modificationTime;
           }
-        }
-        data += 'Ace2Editor.EMBEDED[' + JSON.stringify(filename) + '] = '
-            + JSON.stringify(data_) + ';\n';
-        callback();
-      }
-    }, function(error) {
-      callback(error, data);
+
+          callback();
+        });
+      }, callback);
     });
+  }, function () {
+    callback(null, latestModification);
   });
 }
 
-exports.requireDefinition = requireDefinition;
+// This should be provided by the module, but until then, just use startup
+// time.
+var _requireLastModified = new Date();
+function requireLastModified() {
+  return _requireLastModified.toUTCString();
+}
 function requireDefinition() {
   return 'var require = ' + RequireKernel.kernelSource + ';\n';
 }
 
-function tarCode(jsFiles, write, callback) {
-  write('require.define({');
-  var initialEntry = true;
-  async.forEach(jsFiles, function (filename, callback){
-    if (filename == 'ace.js') {
-      getAceFile(handleFile);
+function getFileCompressed(filename, contentType, callback) {
+  getFile(filename, function (error, content) {
+    if (error || !content) {
+      callback(error, content);
     } else {
-      fs.readFile(JS_DIR + filename, "utf8", handleFile);
-    }
-
-    function handleFile(err, data) {
-      if(ERR(err, callback)) return;
-      var srcPath = JSON.stringify('/' + filename);
-      var srcPathAbbv = JSON.stringify('/' + filename.replace(/\.js$/, ''));
-      if (!initialEntry) {
-        write('\n,');
-      } else {
-        initialEntry = false;
-      }
-      write(srcPath + ': ')
-      data = '(function (require, exports, module) {' + data + '})';
       if (settings.minify) {
-        write(compressJS([data]));
-      } else {
-        write(data);
-      }
-      if (srcPath != srcPathAbbv) {
-        write('\n,' + srcPathAbbv + ': null');
+        if (contentType == 'text/javascript') {
+          try {
+            content = compressJS([content]);
+          } catch (error) {
+            // silence
+          }
+        } else if (contentType == 'text/css') {
+          content = compressCSS([content]);
+        }
       }
-
-      callback();
+      callback(null, content);
     }
-  }, function () {
-    write('});\n');
-    callback();
   });
 }
 
+function getFile(filename, callback) {
+  if (filename == 'js/ace.js') {
+    getAceFile(callback);
+  } else if (filename == 'js/require-kernel.js') {
+    callback(undefined, requireDefinition());
+  } else {
+    fs.readFile(ROOT_DIR + filename, callback);
+  }
+}
+
 function compressJS(values)
 {
   var complete = values.join("\n");
diff --git a/node/utils/Settings.js b/node/utils/Settings.js
index efa22694..0d30fb68 100644
--- a/node/utils/Settings.js
+++ b/node/utils/Settings.js
@@ -57,6 +57,11 @@ exports.requireSession = false;
 exports.editOnly = false;
 
 /**
+ * Max age that responses will have (affects caching layer).
+ */
+exports.maxAge = 1000*60*60*6; // 6 hours
+
+/**
  * A flag that shows if minification is enabled or not
  */
 exports.minify = true;
diff --git a/node/utils/caching_middleware.js b/node/utils/caching_middleware.js
new file mode 100644
index 00000000..809bb210
--- /dev/null
+++ b/node/utils/caching_middleware.js
@@ -0,0 +1,175 @@
+/*
+ * 2011 Peter 'Pita' Martischka (Primary Technology Ltd)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+var async = require('async');
+var Buffer = require('buffer').Buffer;
+var fs = require('fs');
+var path = require('path');
+var server = require('../server');
+var zlib = require('zlib');
+var util = require('util');
+
+var ROOT_DIR = path.normalize(__dirname + "/../");
+var CACHE_DIR = ROOT_DIR + '../var/';
+
+var responseCache = {};
+
+/*
+  This caches and compresses 200 and 404 responses to GET and HEAD requests.
+  TODO: Caching and compressing are solved problems, a middleware configuration
+  should replace this.
+*/
+
+function CachingMiddleware() {
+}
+CachingMiddleware.prototype = new function () {
+  function handle(req, res, next) {
+    if (!(req.method == "GET" || req.method == "HEAD")) {
+      return next(undefined, req, res);
+    }
+
+    var old_req = {};
+    var old_res = {};
+
+    var supportsGzip =
+        req.header('Accept-Encoding', '').indexOf('gzip') != -1;
+
+    var path = require('url').parse(req.url).path;
+    var cacheKey = (new Buffer(path)).toString('base64').replace(/[\/\+=]/g, '');
+
+    fs.stat(CACHE_DIR + 'minified_' + cacheKey, function (error, stats) {
+      var modifiedSince = (req.headers['if-modified-since']
+          && new Date(req.headers['if-modified-since']));
+      var lastModifiedCache = stats && stats.mtime;
+      if (lastModifiedCache) {
+        req.headers['if-modified-since'] = lastModifiedCache.toUTCString();
+      } else {
+        delete req.headers['if-modified-since'];
+      }
+
+      // Always issue get to downstream.
+      old_req.method = req.method;
+      req.method = 'GET';
+
+      var expirationDate = new Date(((responseCache[cacheKey] || {}).headers || {})['expires']);
+      if (expirationDate > new Date()) {
+        // Our cached version is still valid.
+        return respond();
+      }
+
+      var _headers = {};
+      old_res.setHeader = res.setHeader;
+      res.setHeader = function (key, value) {
+        _headers[key.toLowerCase()] = value;
+        old_res.setHeader.call(res, key, value);
+      };
+
+      old_res.writeHead = res.writeHead;
+      res.writeHead = function (status, headers) {
+        var lastModified = (res.getHeader('last-modified')
+            && new Date(res.getHeader('last-modified')));
+
+        res.writeHead = old_res.writeHead;
+        if (status == 200 || status == 404) {
+          // Update cache
+          var buffer = '';
+
+          Object.keys(headers).forEach(function (key) {
+            res.setHeader(key, headers[key]);
+          });
+          headers = _headers;
+          responseCache[cacheKey] = {statusCode: status, headers: headers};
+
+          old_res.write = res.write;
+          old_res.end = res.end;
+          res.write = function(data, encoding) {
+            buffer += data.toString(encoding);
+          };
+          res.end = function(data, encoding) {
+            async.parallel([
+              function (callback) {
+                var path = CACHE_DIR + 'minified_' + cacheKey;
+                fs.writeFile(path, buffer, function (error, stats) {
+                  callback();
+                });
+              }
+            , function (callback) {
+                var path = CACHE_DIR + 'minified_' + cacheKey + '.gz';
+                zlib.gzip(buffer, function(error, content) {
+                  if (error) {
+                    callback();
+                  } else {
+                    fs.writeFile(path, content, function (error, stats) {
+                      callback();
+                    });
+                  }
+                });
+              }
+            ], respond);
+          };
+        } else if (status == 304) {
+          // Nothing new changed from the cached version.
+          old_res.write = res.write;
+          old_res.end = res.end;
+          res.write = function(data, encoding) {};
+          res.end = function(data, encoding) { respond() };
+        } else {
+          res.writeHead(status, headers);
+        }
+      };
+
+      next(undefined, req, res);
+
+      // This handles read/write synchronization as well as its predecessor,
+      // which is to say, not at all.
+      // TODO: Implement locking on write or ditch caching of gzip and use
+      // existing middlewares.
+      function respond() {
+        req.method = old_req.method || req.method;
+        res.write = old_res.write || res.write;
+        res.end = old_res.end || res.end;
+
+        var headers = responseCache[cacheKey].headers;
+        var statusCode = responseCache[cacheKey].statusCode;
+
+        var pathStr = CACHE_DIR + 'minified_' + cacheKey;
+        if (supportsGzip && (headers['content-type'] || '').match(/^text\//)) {
+          pathStr = pathStr + '.gz';
+          headers['content-encoding'] = 'gzip';
+        }
+
+        var lastModified = (headers['last-modified']
+            && new Date(headers['last-modified']));
+
+        if (statusCode == 200 && lastModified <= modifiedSince) {
+          res.writeHead(304, headers);
+          res.end();
+        } else if (req.method == 'GET') {
+          var readStream = fs.createReadStream(pathStr);
+          res.writeHead(statusCode, headers);
+          util.pump(readStream, res);
+        } else {
+          res.writeHead(200, headers);
+          res.end();
+        }
+      }
+    });
+  }
+
+  this.handle = handle;
+}();
+
+module.exports = CachingMiddleware;
diff --git a/package.json b/package.json
index 27b2125a..35c3028a 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,8 @@
                         "name": "Robin Buse" }
                      ],
   "dependencies"   : {
+                      "yajsml"              : "1.1.1",
+                      "request"             : "2.9.100",
                       "require-kernel"      : "1.0.3",
                       "socket.io"           : "0.8.7",
                       "ueberDB"             : "0.1.7",
diff --git a/settings.json.template b/settings.json.template
index 7cd0e819..57bc5711 100644
--- a/settings.json.template
+++ b/settings.json.template
@@ -38,6 +38,10 @@
   /* if true, all css & js will be minified before sending to the client. This will improve the loading performance massivly, 
      but makes it impossible to debug the javascript/css */
   "minify" : true,
+
+  /* How long may clients use served javascript code? Without versioning this
+    is may cause problems during deployment. */
+  "maxAge" : 1000*60*60*6, // 6 hours
   
   /* This is the path to the Abiword executable. Setting it to null, disables abiword.
      Abiword is needed to enable the import/export of pads*/  
diff --git a/static/js/ace.js b/static/js/ace.js
index 6c7bb84e..22d4eaa6 100644
--- a/static/js/ace.js
+++ b/static/js/ace.js
@@ -166,17 +166,15 @@ function Ace2Editor()
   }
   function pushScriptsTo(buffer) {
     /* Folling is for packaging regular expression. */
-    /* $$INCLUDE_JS("../static/js/ace2_inner.js"); */
-    var ACE_SOURCE = '../static/js/ace2_inner.js';
+    /* $$INCLUDE_JS("../minified/ace2_inner.js?callback=require.define"); */
+    var ACE_SOURCE = '../minified/ace2_inner.js?callback=require.define';
     if (Ace2Editor.EMBEDED && Ace2Editor.EMBEDED[ACE_SOURCE]) {
       buffer.push('<script type="text/javascript">');
       buffer.push(Ace2Editor.EMBEDED[ACE_SOURCE]);
       buffer.push('require("/ace2_inner");');
       buffer.push('<\/script>');
     } else {
-      file = ACE_SOURCE;
-      file = file.replace(/^\.\.\/static\/js\//, '../minified/');
-      buffer.push('<script type="application/javascript" src="' + file + '"><\/script>');
+      buffer.push('<script type="application/javascript" src="' + ACE_SOURCE + '"><\/script>');
       buffer.push('<script type="text/javascript">');
       buffer.push('require("/ace2_inner");');
       buffer.push('<\/script>');
diff --git a/static/pad.html b/static/pad.html
index 6f966550..24c90970 100644
--- a/static/pad.html
+++ b/static/pad.html
@@ -291,7 +291,7 @@
 
         <script type="text/javascript" src="../static/js/require-kernel.js"></script>
         <script type="text/javascript" src="../socket.io/socket.io.js"></script>
-        <script type="text/javascript" src="../minified/pad.js"></script>
+        <script type="text/javascript" src="../minified/pad.js?callback=require.define"></script>
         <script type="text/javascript" src="../static/custom/pad.js"></script>
         <script type="text/javascript">
             var clientVars = {};
diff --git a/static/timeslider.html b/static/timeslider.html
index 579e26ef..c629857a 100644
--- a/static/timeslider.html
+++ b/static/timeslider.html
@@ -199,7 +199,7 @@
 
 <script type="text/javascript" src="../../static/js/require-kernel.js"></script>
 <script type="text/javascript" src="../../socket.io/socket.io.js"></script>
-<script type="text/javascript" src="../../minified/timeslider.js"></script>
+<script type="text/javascript" src="../../minified/timeslider.js?callback=require.define"></script>
 <script type="text/javascript" src="../../static/custom/timeslider.js"></script>
 <script type="text/javascript" >
   var clientVars = {};