--- Bob Lee <[EMAIL PROTECTED]> wrote:
>
>
> My point still holds true--Pico requires more code
> than Guice.
Structly speaking using pico in a webapp requires no
code at all (except of course container configuration
in xml or whatever else)
>
> And annotation introduces explicit dependency to
> > framework - kind of uncool.
>
>
> It's a tradeoff--I'll take easier maintainability
> and more concise code.
Well, as said before there is no code related to pico
at all. ( in classes being injected )
What is with third party libraries, which do not know
anything about guice? It is really easy to inject
velocity engine with pico ( for example to compose
email message ):
( taken from my webapp, application scope )
-----------%<-------------
<!--
properties for velocity engine for mail system
-->
<implementation key="renderProperties"
class="org.picocontainer.gems.util.ConstructableProperties">
<constant>
<string>render.properties</string>
</constant>
</implementation>
<!--
velocity engine
-->
<implementation
class="org.apache.velocity.app.VelocityEngine">
<dependency key="renderProperties"/>
</implementation>
-----------%<-------------
( well, I need little more verbose explicit
configuration because I have more than one properties
object )
Now every object which likes to use velocity engine
just gets it.
And velocity remains the same vanilla velocity coming
out of maven repository at apache.
If I understood you correctly, in guice there will be
need to write some adapter / factory. Who got more
code?
> If I choose to not to provide such constructor -
> > then container can not instantiate this component
> -
> > there will be an ugly telling you to provide
> > dependency.
>
>
> When does Pico give you this error? Guice gives you
> a pretty message at
> startup as opposed to runtime. It even points you to
> the class and place
> where you bound it.
At container verification. AFAIR this happens before
container in question is "started" - also pretty soon.
It also tells what is missing ( and depending on WW
setup this even comes on the page )
> ------------%<---------------
> > <!--
> > security and user management components
> > -->
> >
> > <implementation key="securitySession"
> >
>
class="org.nanocontainer.persistence.hibernate.FailoverSessionDelegator">
> > <dependency key="userSessionFactory"/>
> > </implementation>
> >
> > <implementation key="securityLifecycle"
> >
>
class="org.nanocontainer.persistence.hibernate.SessionLifecycle">
> > <dependency key="securitySession"/>
> > </implementation>
> >
> >
> > <!--
> > user manager
> > -->
> > <implementation key="userManager"
> >
> class="de.jtec.user.hibernate.HibernateUserManager">
> > <dependency key="securitySession"/>
> > <dependency key="hasher"/>
> > </implementation>
> >
> > --------------%<----------------
>
>
> It's difficult to say exactly because the example is
> slightly incomplete,
> but the equivalent of this in Guice is:
Well, this was request scope ( as hibernate session is
best opened in view ;) ). In aplication scope you will
need something like this:
-------------%<------------------
<!-- hibernate configuration & session factory
for jtec-user -->
<implementation key="userDbConfig"
class="org.nanocontainer.persistence.hibernate.ConstructableConfiguration">
<constant>
<string>/jtec-user-hibernate.cfg.xml</string>
</constant>
</implementation>
<implementation key="userSessionFactory"
class="org.nanocontainer.persistence.hibernate.SessionFactoryDelegator">
<dependency key="userDbConfig"/>
</implementation>
----------------%<--------------
Again, explicit dependencies and keys are provided
to avoid ambiguity as there are more hibernate
domains.
> bind(Session.class)
> .annotatedWith(Secure.class)
> .to(FailoverSessionDelegator.class);
>
> Then apply "@Inject @Secure" wherever you want a
> secure Session. You can
> obviously reuse the @Secure annotation elsewhere,
> too.
Correct me if I'm wrong ( due to lack of complete
undertanging of guice ), but this means that you
need to tell explicitely that org.hibernate.Session
would be represented by FailoverSessionDelegator
class?
What if I like to use another session impl in the same
container?
You do not have to specify this with pico - your
constructor states it need Session , container looks
for implementation of session. If there is one than
one available - ambiguity shall be resolved by means
of explicit mapping ( no difference with guice? )
> Now any WW2/S2 action wishing to have reference to
> > UserManager needs to declare it as constructor
> > parameter.
>
>
> Guice's Struts 2 plugin injects interceptors and
> results, too.
>
> Guice also supports scoping using annotations. For
> example, you can apply
> @SessionScoped to an action and it will be stored in
> the session.
Scoping is another issue. Guice users depend on your
wisdom to provide them with annotations. If those
annotations are to be applied on some framework (
say, my menu framework for example ), then there is a
leak of concepts - I have to decide component scope
in a project which has nothing to do with web
application ( but will be used for it ). What if I
need different scope?
There could be also way more scopes than usual
suspects (application /session/request )?
( Look at nanocontainer chains - every directory in
webapp can be own scope, this helps to hide
somponents from each other. I also use those nested
scopes to control access to parts of website:
--------------%<-----------------
<container>
<implementation
class="de.jtec.security.LoginChecker"/>
<!-- activate contact entry we are at home -->
<implementation
class="de.jtec.menu.util.EntryActivator">
<dependency key="siteMenu"/>
<dependency key="entryLocator"/>
<constant>
<string>menu.dashboard</string>
</constant>
</implementation>
</container>
--------------%<-----------------
( No request will be served beyond directory
assotiated with container unless there is valid user
login.
This automatically secures all actions mapped in
corresponding package at virtually no cost. Also
activates certain menu entry )
This is also good for wizard-like applications,
providing DAO-Classes for parts of website where they
are really needed, or to check for some precondition
like "to be able to use actions from this package you
should have selected something before:
-------------%<-----------------
<container>
<!-- require open account -->
<implementation
class="de.kesselweb.mydiablo.data.edit.AccountChecker"/>
</container>
-----------%<--------------
This small component would require that account was
seslected for edit before, otherwise it will force
redirect to appropriate page.
> PS: is project space on code.google.com available
> only
> > for employees or also for mere mortals?
>
>
> Google Code is open to anyone!
who got gmail ;) looks like product marketing by
blackmail ;)
> Bob
Konstantin
----[ Konstantin Pribluda http://www.pribluda.de ]----------------
Still using XDoclet 1.x? XDoclet 2 is released and of production quality.
check it out: http://xdoclet.codehaus.org
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