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Posted to users@wicket.apache.org by "Brown, Berlin [GCG-PFS]" <Be...@Primerica.com> on 2010/06/15 21:11:35 UTC
Newbie question anti-patterns and wicket, constructor component
building
I am sorry, am just getting used to Wicket but I notice a lot of use of
calling a lot of code in the constructor. Does it really matter? I
mention it because this kind of style makes it difficult to test code
because code in the constructor may fail and the object won't be
created.
Should I just create a method and call that method in the constructor?
Re: Newbie question anti-patterns and wicket, constructor component
building
Posted by Jeremy Thomerson <je...@wickettraining.com>.
>
>
> Well, the second version uses constructer injection. Some frameworks
> prefer that approach.
>
> But, I see your point.
>
You should not be calling a service or dao directly in your constructor,
regardless of whether you are using dependency injection or not. This is
bad. That's what models are for. Load data in models - not while
constructing an object.
--
Jeremy Thomerson
http://www.wickettraining.com
Re: Newbie question anti-patterns and wicket, constructor component
building
Posted by Jeremy Thomerson <je...@wickettraining.com>.
>
>
> Well, the second version uses constructer injection. Some frameworks
> prefer that approach.
>
> But, I see your point.
>
You should not be calling a service or dao directly in your constructor,
regardless of whether you are using dependency injection or not. This is
bad. That's what models are for. Load data in models - not while
constructing an object.
--
Jeremy Thomerson
http://www.wickettraining.com
RE: Newbie question anti-patterns and wicket, constructor
component building
Posted by "Brown, Berlin [GCG-PFS]" <Be...@Primerica.com>.
-----Original Message-----
From: Jeremy Thomerson [mailto:jeremy@wickettraining.com]
Sent: Tuesday, June 15, 2010 3:25 PM
To: users@wicket.apache.org
Subject: Re: Newbie question anti-patterns and wicket, constructor
component building
On Tue, Jun 15, 2010 at 2:11 PM, Brown, Berlin [GCG-PFS] <
Berlin.Brown@primerica.com> wrote:
> I am sorry, am just getting used to Wicket but I notice a lot of use
> of calling a lot of code in the constructor. Does it really matter?
> I mention it because this kind of style makes it difficult to test
> code because code in the constructor may fail and the object won't be
> created.
>
> Should I just create a method and call that method in the constructor?
>
The constructor is supposed to construct the object. In Wicket, this
also
(typically) means constructing the component hierarchy. So, your
constructor should be doing things like add(new FooPanel("foo", new
SomeModel())); It should NOT be doing things like:
List<Foo> foos = SomeDao.loadAll();
new FooPanel("foo", foos);
That's the kind of code I see newbs putting in their constructor all the
time - and it should NOT be there.
--
Jeremy Thomerson
http://www.wickettraining.com
-----
Well, the second version uses constructer injection. Some frameworks
prefer that approach.
But, I see your point.
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Re: Newbie question anti-patterns and wicket, constructor component
building
Posted by Jeremy Thomerson <je...@wickettraining.com>.
On Tue, Jun 15, 2010 at 2:11 PM, Brown, Berlin [GCG-PFS] <
Berlin.Brown@primerica.com> wrote:
> I am sorry, am just getting used to Wicket but I notice a lot of use of
> calling a lot of code in the constructor. Does it really matter? I
> mention it because this kind of style makes it difficult to test code
> because code in the constructor may fail and the object won't be
> created.
>
> Should I just create a method and call that method in the constructor?
>
The constructor is supposed to construct the object. In Wicket, this also
(typically) means constructing the component hierarchy. So, your
constructor should be doing things like add(new FooPanel("foo", new
SomeModel())); It should NOT be doing things like:
List<Foo> foos = SomeDao.loadAll();
new FooPanel("foo", foos);
That's the kind of code I see newbs putting in their constructor all the
time - and it should NOT be there.
--
Jeremy Thomerson
http://www.wickettraining.com