On Thursday, January 24, 2013 4:12:43 PM UTC+1, Darsha Sai wrote: > > Hi Thomas, > > Thanks for your response. > > I am not using MVP . >
activities != MVP (see "debunking misconceptions" at http://tbroyer.posterous.com/gwt-21-places) > I am not using PlaceController . So I only relay on > History.addValueChangeHandler. > > What problem I am facing is ... > > In GWT have History ,HistoryImpl classes. > > HistoryImpl class have newItem() , newItemOnEvent() these two final > methods will change the $wnd.location.hash value when we click on browser > back button. > > Moreover, GWT have different HistoryImpl classes for browser specific > and contain native methods to update the $wnd.location.hash . > Like under package com.google.gwt.user.client.impl > > HistoryImpl > HistoryImplIE6 > HistoryImplMozilla > HistoryImplSafari > HistoryImplTimer > > > *For Example :* In Mozilla browser , if I click on browser back > button,control is going to HistoryImplMozilla (see below GWT > implementation in History.gwt.xml) and change the the browser URL in > "nativeUpdate" method and then control will come to > History.addValueChangeHandler (onValueChange()) at this time the browser > URL already modified and difficult to get the original URL from here. > > History.gwt.xml > > <!-- Mozilla has a slightly different history implementation than the > --> > <!-- standard case. > --> > <replace-with class="com.google.gwt.user.client.impl.HistoryImplMozilla"> > <when-type-is class="com.google.gwt.user.client.impl.HistoryImpl"/> > <any> > <when-property-is name="user.agent" value="gecko1_8"/> > <when-property-is name="user.agent" value="gecko"/> > </any> > </replace-with> > > How to show the alert message in this time ? in Alert message if user > clicks to NO button means wants to stay in same page then its difficult to > get the original URL . because original URL already modified. > > In which place is suitable for showing Alert message to the user if form > is dirty and clicks on browser back button. > You have basically two solutions: - globally; you'll have to somehow ask the "current form" whether it's dirty or not and depending on that display a confirm message - at the form level; addValueChangeHandler when the form is displayed, removeHandler when navigating away In any case, you can either live with the history token no longer representing your current "place" (see https://code.google.com/p/google-web-toolkit/issues/detail?id=6726) or track the current token and issue a History.newItem() when you want to "cancel" the navigation to "reinstall" the current token. > Its difficult to customize the HistoryImpl class for newItem() , > newItemOnEvent() these are final methods can't over ride in sub classes. If > i do that (copy entire class and done the customize) I need to customize > History ,HistoryImpl ,HistoryImplIE6,HistoryImplMozilla , HistoryImplSafari > ,HistoryImplTimer. > These are implementation details, you don't need to (and shouldn't) mess with them. -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to google-web-toolkit@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/google-web-toolkit?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
