implemented basic client-global caching mechanisms

process/DataCaching_lib/DataCaching_lib.aod

+<?xml version="1.0" encoding="UTF-8"?>
+<process xmlns="http://www.adito.de/2018/ao/Model" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" VERSION="1.2.1" xsi:schemaLocation="http://www.adito.de/2018/ao/Model adito://models/xsd/process/1.2.1">
+  <name>DataCaching_lib</name>
+  <majorModelMode>DISTRIBUTED</majorModelMode>
+  <process>%aditoprj%/process/DataCaching_lib/process.js</process>
+  <variants>
+    <element>LIBRARY</element>
+  </variants>
+</process>

process/DataCaching_lib/process.js

+import("system.vars");
+
+
+function CachedData(pIdentifiyingName, pKeepPerLanguage)
+{
+    this.identifyingName = pIdentifiyingName;
+    this.keepPerLanguage = pKeepPerLanguage;
+    
+    this.runningOnServer = vars.getString("$sys.isserver") == "true";
+    if (this.runningOnServer)
+        this.locale = vars.get("$sys.serverlocale");
+    else
+        this.locale = (this.keepPerLanguage ? vars.get("$sys.clientlocale") : "_anyLanguage_");
+}
+
+CachedData.make = function(pIdentifiyingName, pKeepPerLanguage, pDataCallbackFunction)
+{
+    return (new CachedData(pIdentifiyingName, pKeepPerLanguage)).load(pDataCallbackFunction);
+}
+
+CachedData.prototype.load = function(pDataCallbackFunction)
+{
+    //currently it's not possible to cache the data within the serer-context, so inestead the Data-function is called everytime
+    if (this.runningOnServer)
+        return pDataCallbackFunction.call(this, this.keepPerLanguage, this.locale);
+    else
+    {
+        var varname = this.getVariableName();
+        var data;
+        if (vars.exists(varname))
+        {
+            data = vars.get(varname);
+            if (data != null)
+                return data;
+        }
+        
+        data = pDataCallbackFunction.call(this, this.keepPerLanguage, this.locale);
+        vars.set(varname, data);
+        this._register();
+        return data;
+    }
+};
+
+CachedData.prototype.unload = function()
+{
+    var varname = this.getVariableName();
+    vars.set(varname, null);
+    this._unregister();
+}
+
+CachedData.prototype.getVariableName = function()
+{
+    var PREFIX = "$global.CachedData.";        
+    var res = PREFIX + this.identifyingName + "." + this.locale;
+    return res;
+}
+
+CachedData.getRegistryName = function()
+{
+    return "$global.CachedDataRegistry";
+}
+
+CachedData.getRegistry = function()
+{
+    var registryVarname = CachedData.getRegistryName();
+    if (vars.exists(registryVarname))
+        return vars.get(registryVarname);
+    else
+        return {};
+}
+
+CachedData.prototype._register = function()
+{
+    var registry = CachedData.getRegistry();
+    if (registry[this.getVariableName()] != undefined)
+        throw new Error("Already registered. cannot register the same object twice");//TODO: message
+    else
+        registry[this.getVariableName()] = {keepPerLanguage: this.keepPerLanguage};
+    vars.set(CachedData.getRegistryName(), registry);
+};
+
+CachedData.prototype._unregister = function()
+{
+    var registry = CachedData.getRegistry();
+   if (registry[this.getVariableName()] == undefined)
+        throw new Error("Item not found. cannot unregister");//TODO: message
+    else
+        delete registry[this.getVariableName()];
+    vars.set(CachedData.getRegistryName(), registry);
+};