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Programming__WebObjects-Web Applications-Development-Examples-Login

Version 2.1 by smmccraw on 2007/07/08 09:45

Simple Login

Here is a little example on how to redirect a request to a "login" page if necessary:

  public void appendToResponse(WOResponse aResponse, WOContext aContext)
  {
    String aPageName = LoginPage.pageWithContext( aContext );
 
    if ( ( aPageName !=_null_)_&&_(_this.name().equals(_aPageName_)_==_false_)_)
{
WOComponent aComponent_=_this.pageWithName(_aPageName_);

this.currentSession().setPage(_aPageName_);
aContext._setPageComponent(_aComponent_);
aContext._setCurrentComponent(_aComponent_);
aComponent.appendToResponse(_aResponse,_aContext);

return;
}

this.currentSession().setPage(_this.name()_);
super.appendToResponse(_aResponse,_aContext);
}

WOContext.setPageComponent()andWOContext.setCurrentComponent()areundocumentedmethods,butarerequiredinordertoupdatetheWOContextwiththecurrentpageandcomponentinformation.

TheLoginPageclass(notshown)willdecideifaloginisnecessaryornot.

AvoidingSessionTimeoutsatLogin

Agoodloginshouldnottimeoutwhennouserisloggedin.Thiscanbeaproblemifyourapplicationusesasessioninthepagegeneration.

FortunatelyApplehasprovideduswithawayofdoingthiscorrectly:"DirectAction";.YoushouldimplementyourloginpageasaDirectActionandbeverycarefulnottocreatea"lazy"sessionotherwiseyouwillhaveworkedfornothing.WOcreateasessionwhenyoucallcertainmethodssoyouhavetobecareful.Usethis.context().hasSession()tocheckthateverythingisOK.Aftersuccessfulloginyoucreateasessionbycallingthis.session()inyourcomponentandstoretheuserinit;youareinbusiness.

Onlogoutyoudestroythesessionandreturnthedirectactionpagethatwaytheuserhasanewloginscreeninsteadofanemptyscreen.Theeasiestwayofgeneratingaloginpageonlogoutistoreturnaredirectpage(302)tothemainURLoftheapplicationitistransparenttotheuseranddoesexactlywhatyouneed.

Youwillfindthecodesamplethereafter.IplaceitintheApplicationandwhenIwanttologoutIjustcallhandleLogoutwiththecontext.

private_WOResponse_responseForPageWithName(String_aPageName,_WOContext_aContext)_{
if_(_aPageName_!= null ) {
        WOResponse aResponse = new WOResponse();
        String adaptorPrefix = aContext.request().adaptorPrefix();
        String applicationName = aContext.request().applicationName();
        String anURL = adaptorPrefix + "/" + applicationName + ".woa";
        aResponse.setHeader(anURL, "Location");
        aResponse.setHeader("text/html", "content-type");
        aResponse.setHeader("0","content-length");
        aResponse.setStatus(302);
        return aResponse;
    }
    return null;
  }
 
  public WOResponse handleLogout(WOContext aContext) {
    WOResponse aResponse = this.responseForPageWithName("Login", aContext);
    if ( ! aContext.session().isTerminating() ) {
        ((Session)aContext.session()).setUser(null);
        aContext.session().terminate();
    }
    return aResponse;
  }

Category:WebObjects