Unanswered: [GXT3.0][ Does gxt3.0 contain the class of Registry
after updating gxt to version 3.0, the code show the error class of Registry not found which is located in the package com.extjs.gxt.ui.client at version2. Does gxt3.0 contain the class of Registry? if didnt,what will replace it ?
this is a pretty critical question. why doesn't any one answer it?
what is the substitute in Gxt 3 for replacing the Registry class?
The 2.x Registry class is essentially a global, untyped map with string keys. This can be very handy for storing singletons, but one can very easily reproduce the exact same functionality as simply as just copying the concept and making your own. Not including headers and imports, the file only has about 50 lines of code - which includes whitespace, javadocs, and method declarations.
In 3.x, we've removed Registry, the 2.x event model, and the ModelData itself - these all encouraged a style of programming that makes it very hard for developers to write consistently typed code - a change in the inheritance in one part of the app can cause runtime ClassCastException errors in another.
Instead of the Registry, consider some kind of way to describe common instances, or how to obtain new objects across your app. One such way is through dependency injection (also known as inversion of control, or IoC). This can be done with the help of a tool like Gin, or can also be manually managed using something like the ClientFactory DI pattern used in many GWT examples.
Some additional resources of DI/ClientFactory/Gin that you might find useful:
https://developers.google.com/web-to...itiesAndPlaces (Specifically read the section on ClientFactory, but the whole article, as well as the two links on MVP, can be useful as some possible approaches for app design. These are all just some possible proposals though - none are considered to be the One True GWT Way.)