ExtJS Loader Success Callback Source

First, loader has several important attributes.

Queue: [] holds all Master file class information, including his dependent file information, as follows: [{requires: ' Seed.view.MainGrid ' callback:callback//Loader. Require (Dependencies,function () {}); Note: All dynamically loaded file information will be placed in the queue isloading: Loading numloadedfiles: The number of completed files has been loaded n Umpendingfiles: Number of items to load seriptsloading: number of files being loaded isclassfileloaded: {} object stores all classes and whether they have been loaded

The callback method is called when the file is loaded, parsing is complete:

if  (' AddEventListener '  in script )  {                 script.onload = onLoadFn;             } else if  (' readyState '  in script)  {   // for <IE9 Compatability                 script.onreadystatechange = function ()  {                      if  ( this.readyState ==  ' Loaded '  | |  this.readyState ==  ' complete '  )  {         &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;ONLOADFN ();                     }                 };             } else {                  script.onload = onLoadFn;             }

Callback methods, which were previously involved, are as follows:

Onfileloaded: function (Classname, filepath)  {         Whether the     var loaded = isClassFileLoaded[className]; //  file has been loaded             Loader.numLoadedFiles++; //  Loaded quantity plus 1            isclassfileloaded[classname]  = true; //  tagged file has been loaded              isFileLoaded[filePath] = true;             // In FF, when we sync load something that has  had a script tag inserted, the load event may             // sometimes fire even if we  Clean it up and&nbSp;set it to null, so check if we ' Re already loaded here.             if  (!loaded)  { //  If the file has not been loaded before, then the load count minus 1                 loader.numpendingfiles--;            }             if  (loader.numpendingfiles = == 0)  { //  when the number to load is 0                 loader.refreshqueue ();           Treatment of   }            // missingclasses , slightly         }

When the number to load is 0, execute loader.refreshqueue (), as follows:

Refreshqueue: function ()  {             var ln = queue.length,                 i, item, j, requires;             // When the queue of loading classes reaches  Zero, trigger readiness            if   (!ln && ! loader.scriptsloading)  { // , recursive end condition: Load queue is empty                  return loader.triggerready (); //  Triggerready See below             }             for  (i = 0; i < ln;  i++) &NBsp { //  each object in a looping queue                  item = queue[i];                 if  (item)  {                     requires = item.requires;                     //  don ' t bother checking when the number of files loaded                      // is still less than the array length                     if  ( Requires.length > loAder.numloadedfiles)  {                         continue;                     }                     //  remove any required classes that are loaded                     for  (j = 0;  j < requires.length; )  {                         if  ( Manager.iscreated (Requires[j])  { //  If a dependency class A of item is already created, remove it from the require of item                               // Take out from the queue                              arrayerase (requires, j, 1);                         }                          else {                             j++;                          }                    }                      // if we ' Ve ended up with no required classes, call  the callback                     if  (item.requires.length === 0)  { //  When all dependent files for a class have been loaded, remove the item              from the queue            arrayerase (queue, i, 1);                          item.callback.call (Item.scope);                         loader.refreshqueue ();//  recursion                           break;                     }                 }            }             return Loader;         }

The function of the Refreshqueue () method is to keep the loop detection until all classes are loaded, executed, created, and then called the Triggerready () method, as follows:

Triggerready: function ()  {             var listener,                 refClasses = usedClasses;              if  (loader.isloading)  {                 Loader.isLoading = false;                 if  (refclasses.length !== 0)  {  //  load the path referenced with the USE keyword                      // Clone then empty the array to  eliminate potential recursive loop issue              &Nbsp;      refclasses = refclasses.slice ();                      usedclasses.length = 0;                     // this may immediately call us  back if all  ' uses '  classes                     // have been loaded                      Loader.require (Refclasses, loader.triggerready, loader);                     return Loader;                 }             }            ext.array.sort (ReadyListeners,  comparepriority);// listener sort              // this method can be called with Loader.isLoading either  true or false            //  (CAN  be called with false when all  ' uses '  classes are already  loaded)             // this may  bypass the above if condition             while  (readylisteners.length && ! loader.isloading)  { //  Call callback method    &Nbsp;            // calls to  refreshqueue may re-enter triggerready                 // so we cannot necessarily iterate  the readylisteners array                 listener = readylisteners.shift ();                 listener.fn.call (Listener.scope);             }             return loader;        }

It can be seen from this that the USE keyword relies on classes that are loaded only when other keyword-dependent classes are loaded successfully.

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ExtJS Loader Success Callback Source