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Posted to users@wicket.apache.org by Arjun Dhar <dh...@yahoo.com> on 2016/02/18 07:21:09 UTC

Use a Factory to create a Panel (Yay or Nay)?

Hi,
I have a bunch of Admin panels but i want to be able to override them. The
issue is the pages obviously use "add(new SomeAdminPanel(....))"; 

To overcome this I was thinking or writing a Factory, that via can create
the desired instance of the Panel and pass it to the Page. The factory
internally can use Spring to make this highly configurable.

however, I came across
https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12
(Do not use factories for components)

... can anyone validate if I should let that stop me from doing what I
intend? Maybe Panels are an exception to this rule?! 

thanks

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Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Patrick Davids <pa...@nubologic.com>.
 > I have at times used factories and then found that they made some 
simply things more complicated

I agree... you will loose the feature to sub-class and override 
onConfigure() or onBeforeRender() of your components.

And what I also encountered using factories, when having sub-classed 
model-objects and you want to choose as specific component depending on 
the model-objects subclass, you run into the "unpack on construction 
time" issue, which is also not that good.

And if you want to use shared models for your components and forward 
your model to your via factory constructed component, you will get type 
safety warnings.

e.g. factoryMethod(IModel<Person> personModel){

	if(personModel.getObject() instanceof Employee){
		return new EmployeePanel((IModel<Employee>)personModel);//type safety 
warning
	}else{
		...
	}

}

All this points are somehow "code smells" to me and from the experience 
of the last years I more and more agree with the "bad practice" not to 
use factories for components.

But I never used Spring / SpringFactories... maybe you wont run into the 
described issues... not sure here.

best regards
Patrick


Am 18.02.2016 um 10:12 schrieb Urbani, Edmund:
> Hello,
>
> I have at times used factories and then found that they made some simply
> things more complicated. Eg. I could no longer simply override
> isEnabled() or isVisible() methods to suit the page I was added the
> component to. So I try to avoid factories for Wicket components now
> unless I see a real advantage.
>
> Kind regards,
>   Edmund
>
> On 02/18/2016 09:53 AM, Sven Meier wrote:
>> Hi,
>>
>> I wouldn't use a factory for each and every component (e.g. label).
>> But any sufficiently large Wicket project will benefit from separating
>> it into separate parts which very light interdependencies only: a
>> plugin-based architecture.
>>
>> If you're using Spring factories, you just have to take care that no
>> references to Spring beans leak into the components - something you
>> have easily with inner classes (as in the example listing 15 in the
>> Wicket guide).
>>
>> Have fun
>> Sven
>>
>>
>> On 18.02.2016 09:01, Martin Grigorov wrote:
>>> Hi,
>>>
>>> I don't share the option in the guide.
>>> Using factories when needed is perfectly fine.
>>> Apache Isis uses factories to provide custom UI for almost any part
>>> of the
>>> Wicket viewer.
>>> BrixCMS also uses factories to create tiles.
>>>
>>> Martin Grigorov
>>> Wicket Training and Consulting
>>> https://twitter.com/mtgrigorov
>>>
>>> On Thu, Feb 18, 2016 at 7:21 AM, Arjun Dhar <dh...@yahoo.com> wrote:
>>>
>>>> Hi,
>>>> I have a bunch of Admin panels but i want to be able to override
>>>> them. The
>>>> issue is the pages obviously use "add(new SomeAdminPanel(....))";
>>>>
>>>> To overcome this I was thinking or writing a Factory, that via can
>>>> create
>>>> the desired instance of the Panel and pass it to the Page. The factory
>>>> internally can use Spring to make this highly configurable.
>>>>
>>>> however, I came across
>>>>
>>>> https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12
>>>>
>>>> (Do not use factories for components)
>>>>
>>>> ... can anyone validate if I should let that stop me from doing what I
>>>> intend? Maybe Panels are an exception to this rule?!
>>>>
>>>> thanks
>>>>
>>>> -----
>>>> Software documentation is like sex: when it is good, it is very, very
>>>> good; and when it is bad, it is still better than nothing!
>>>> --
>>>> View this message in context:
>>>> http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622.html
>>>>
>>>> Sent from the Users forum mailing list archive at Nabble.com.
>>>>
>>>> ---------------------------------------------------------------------
>>>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>>>> For additional commands, e-mail: users-help@wicket.apache.org
>>>>
>>>>
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>
>
> --
>
> Mit freundlichen Grüßen
> Edmund Urbani
> Liland IT Team
>
> Email: <ma...@lilandit.com>Edmund.Urbani@Lilandit.com
>
> Liland IT GmbH ...does IT better
> Tel: +43 463 220111
> Fax: +43 463 220111-33
> Tel(GER): +49 221 65028588
>
> Find us at Facebook http://facebook.com/Lilandit
> http://green-badges.com
> http://iventcloud.com
> http://Lilandit.com
>
> <http://www.LilandIT.com> <http://www.LilandIT.com>
>
> Copyright © 2016, Liland IT GmbH
>
> Diese Mail enthaelt vertrauliche und/oder rechtlich geschuetzte
> Informationen.
> Wenn Sie nicht der richtige Adressat sind oder diese Email irrtuemlich
> erhalten haben, informieren Sie bitte sofort den Absender und vernichten
> Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe
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> This email may contain confidential and/or privileged information.
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> error) please notify the sender immediately and destroy this email. Any
> unauthorised copying, disclosure or distribution of the material in this
> email is strictly forbidden.
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Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Sven Meier <sv...@meiers.net>.
Hi,

read here:

http://wicketinaction.com/2011/11/implement-wicket-component-visibility-changes-properly/

Sven


On 21.02.2016 12:40, Peter Henderson wrote:
> On Thu, Feb 18, 2016 at 9:15 AM, Martin Grigorov <mg...@apache.org>
> wrote:
>
>> On Thu, Feb 18, 2016 at 10:12 AM, Urbani, Edmund <
>> edmund.urbani@lilandit.com
>>> wrote:
>>> Hello,
>>>
>>> I have at times used factories and then found that they made some simply
>>> things more complicated. Eg. I could no longer simply override
>> isEnabled()
>>> or isVisible() methods to suit the page I was
>>>
>> Overriding isVisible/isEnabled() is a bad idea anyway!
>> Use onConfigure() + setVisible/setEnabled instead.
>>
>
> Oh dear, I override isVisible/isEnabled quite a lot.
> Why is it considered a bad idea?
>


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Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Peter Henderson <pe...@starjar.com>.
On Thu, Feb 18, 2016 at 9:15 AM, Martin Grigorov <mg...@apache.org>
wrote:

> On Thu, Feb 18, 2016 at 10:12 AM, Urbani, Edmund <
> edmund.urbani@lilandit.com
> > wrote:
>
> > Hello,
> >
> > I have at times used factories and then found that they made some simply
> > things more complicated. Eg. I could no longer simply override
> isEnabled()
> > or isVisible() methods to suit the page I was
> >
>
> Overriding isVisible/isEnabled() is a bad idea anyway!
> Use onConfigure() + setVisible/setEnabled instead.
>


Oh dear, I override isVisible/isEnabled quite a lot.
Why is it considered a bad idea?

Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Martin Grigorov <mg...@apache.org>.
On Thu, Feb 18, 2016 at 10:12 AM, Urbani, Edmund <edmund.urbani@lilandit.com
> wrote:

> Hello,
>
> I have at times used factories and then found that they made some simply
> things more complicated. Eg. I could no longer simply override isEnabled()
> or isVisible() methods to suit the page I was
>

Overriding isVisible/isEnabled() is a bad idea anyway!
Use onConfigure() + setVisible/setEnabled instead.


> added the component to. So I try to avoid factories for Wicket components
> now unless I see a real advantage.
>
> Kind regards,
>  Edmund
>
>
> On 02/18/2016 09:53 AM, Sven Meier wrote:
>
> Hi,
>
> I wouldn't use a factory for each and every component (e.g. label).
> But any sufficiently large Wicket project will benefit from separating it
> into separate parts which very light interdependencies only: a plugin-based
> architecture.
>
> If you're using Spring factories, you just have to take care that no
> references to Spring beans leak into the components - something you have
> easily with inner classes (as in the example listing 15 in the Wicket
> guide).
>
> Have fun
> Sven
>
>
> On 18.02.2016 09:01, Martin Grigorov wrote:
>
> Hi,
>
> I don't share the option in the guide.
> Using factories when needed is perfectly fine.
> Apache Isis uses factories to provide custom UI for almost any part of the
> Wicket viewer.
> BrixCMS also uses factories to create tiles.
>
> Martin Grigorov
> Wicket Training and Consulting
> https://twitter.com/mtgrigorov
>
> On Thu, Feb 18, 2016 at 7:21 AM, Arjun Dhar <dh...@yahoo.com>
> <dh...@yahoo.com> wrote:
>
> Hi,
> I have a bunch of Admin panels but i want to be able to override them. The
> issue is the pages obviously use "add(new SomeAdminPanel(....))";
>
> To overcome this I was thinking or writing a Factory, that via can create
> the desired instance of the Panel and pass it to the Page. The factory
> internally can use Spring to make this highly configurable.
>
> however, I came across
>
>
> https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12
> (Do not use factories for components)
>
> ... can anyone validate if I should let that stop me from doing what I
> intend? Maybe Panels are an exception to this rule?!
>
> thanks
>
> -----
> Software documentation is like sex: when it is good, it is very, very
> good; and when it is bad, it is still better than nothing!
> --
> View this message in context:
>
> http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622.html
> Sent from the Users forum mailing list archive at Nabble.com.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
>
> --
>
> Mit freundlichen Grüßen
> Edmund Urbani
> Liland IT Team
>
> Email: <Ed...@lilandit.com>Edmund.Urbani@Lilandit.com
>
> Liland IT GmbH ...does IT better
> Tel: +43 463 220111
> Fax: +43 463 220111-33
> Tel(GER): +49 221 65028588
>
> Find us at Facebook http://facebook.com/Lilandit
> http://green-badges.com
> http://iventcloud.com
> http://Lilandit.com
>
> <http://www.LilandIT.com> <http://www.LilandIT.com>
>
> Copyright © 2016, Liland IT GmbH
>
> Diese Mail enthaelt vertrauliche und/oder rechtlich geschuetzte
> Informationen.
> Wenn Sie nicht der richtige Adressat sind oder diese Email irrtuemlich
> erhalten haben, informieren Sie bitte sofort den Absender und vernichten
> Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe
> dieser Mail ist nicht gestattet.
>
> This email may contain confidential and/or privileged information.
> If you are not the intended recipient (or have received this email in
> error) please notify the sender immediately and destroy this email. Any
> unauthorised copying, disclosure or distribution of the material in this
> email is strictly forbidden.
>

Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by "Urbani, Edmund" <ed...@lilandit.com>.
Hello,

I have at times used factories and then found that they made some simply things 
more complicated. Eg. I could no longer simply override isEnabled() or 
isVisible() methods to suit the page I was added the component to. So I try to 
avoid factories for Wicket components now unless I see a real advantage.

Kind regards,
  Edmund

On 02/18/2016 09:53 AM, Sven Meier wrote:
> Hi,
>
> I wouldn't use a factory for each and every component (e.g. label).
> But any sufficiently large Wicket project will benefit from separating it into 
> separate parts which very light interdependencies only: a plugin-based 
> architecture.
>
> If you're using Spring factories, you just have to take care that no 
> references to Spring beans leak into the components - something you have 
> easily with inner classes (as in the example listing 15 in the Wicket guide).
>
> Have fun
> Sven
>
>
> On 18.02.2016 09:01, Martin Grigorov wrote:
>> Hi,
>>
>> I don't share the option in the guide.
>> Using factories when needed is perfectly fine.
>> Apache Isis uses factories to provide custom UI for almost any part of the
>> Wicket viewer.
>> BrixCMS also uses factories to create tiles.
>>
>> Martin Grigorov
>> Wicket Training and Consulting
>> https://twitter.com/mtgrigorov
>>
>> On Thu, Feb 18, 2016 at 7:21 AM, Arjun Dhar <dh...@yahoo.com> wrote:
>>
>>> Hi,
>>> I have a bunch of Admin panels but i want to be able to override them. The
>>> issue is the pages obviously use "add(new SomeAdminPanel(....))";
>>>
>>> To overcome this I was thinking or writing a Factory, that via can create
>>> the desired instance of the Panel and pass it to the Page. The factory
>>> internally can use Spring to make this highly configurable.
>>>
>>> however, I came across
>>>
>>> https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12 
>>>
>>> (Do not use factories for components)
>>>
>>> ... can anyone validate if I should let that stop me from doing what I
>>> intend? Maybe Panels are an exception to this rule?!
>>>
>>> thanks
>>>
>>> -----
>>> Software documentation is like sex: when it is good, it is very, very
>>> good; and when it is bad, it is still better than nothing!
>>> -- 
>>> View this message in context:
>>> http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622.html 
>>>
>>> Sent from the Users forum mailing list archive at Nabble.com.
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>>> For additional commands, e-mail: users-help@wicket.apache.org
>>>
>>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>


-- 

Mit freundlichen Grüßen
Edmund Urbani
Liland IT Team

Email: Edmund.Urbani@Lilandit.com <ma...@lilandit.com>

Liland IT GmbH ...does IT better
Tel: +43 463 220111
Fax: +43 463 220111-33
Tel(GER): +49 221 65028588

Find us at Facebook http://facebook.com/Lilandit
http://green-badges.com
http://iventcloud.com
http://Lilandit.com

<http://www.LilandIT.com> <http://www.LilandIT.com>

Copyright © 2016, Liland IT GmbH

Diese Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen.
Wenn Sie nicht der richtige Adressat sind oder diese Email irrtuemlich erhalten 
haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. 
Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail ist nicht 
gestattet.

This email may contain confidential and/or privileged information.
If you are not the intended recipient (or have received this email in error) 
please notify the sender immediately and destroy this email. Any unauthorised 
copying, disclosure or distribution of the material in this email is strictly 
forbidden.

Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Sven Meier <sv...@meiers.net>.
Hi,

I wouldn't use a factory for each and every component (e.g. label).
But any sufficiently large Wicket project will benefit from separating 
it into separate parts which very light interdependencies only: a 
plugin-based architecture.

If you're using Spring factories, you just have to take care that no 
references to Spring beans leak into the components - something you have 
easily with inner classes (as in the example listing 15 in the Wicket 
guide).

Have fun
Sven


On 18.02.2016 09:01, Martin Grigorov wrote:
> Hi,
>
> I don't share the option in the guide.
> Using factories when needed is perfectly fine.
> Apache Isis uses factories to provide custom UI for almost any part of the
> Wicket viewer.
> BrixCMS also uses factories to create tiles.
>
> Martin Grigorov
> Wicket Training and Consulting
> https://twitter.com/mtgrigorov
>
> On Thu, Feb 18, 2016 at 7:21 AM, Arjun Dhar <dh...@yahoo.com> wrote:
>
>> Hi,
>> I have a bunch of Admin panels but i want to be able to override them. The
>> issue is the pages obviously use "add(new SomeAdminPanel(....))";
>>
>> To overcome this I was thinking or writing a Factory, that via can create
>> the desired instance of the Panel and pass it to the Page. The factory
>> internally can use Spring to make this highly configurable.
>>
>> however, I came across
>>
>> https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12
>> (Do not use factories for components)
>>
>> ... can anyone validate if I should let that stop me from doing what I
>> intend? Maybe Panels are an exception to this rule?!
>>
>> thanks
>>
>> -----
>> Software documentation is like sex: when it is good, it is very, very
>> good; and when it is bad, it is still better than nothing!
>> --
>> View this message in context:
>> http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622.html
>> Sent from the Users forum mailing list archive at Nabble.com.
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>>


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Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Arjun Dhar <dh...@yahoo.com>.
Thanks martin for the validation. Just to add to the group discussion, when
developing a CMS (esp for E-Commerce) you do want other developers to at
some point override any default Panels in your base UI with their own
Plugin-ins. .. that was my intent.

Even if someone feels factories are not a good idea, I request an alternate.
Though, I feel it looks good as a solution and nice to have some validation.

thanks



-----
Software documentation is like sex: when it is good, it is very, very good; and when it is bad, it is still better than nothing!
--
View this message in context: http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622p4673642.html
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Re: Use a Factory to create a Panel (Yay or Nay)?

Posted by Martin Grigorov <mg...@apache.org>.
Hi,

I don't share the option in the guide.
Using factories when needed is perfectly fine.
Apache Isis uses factories to provide custom UI for almost any part of the
Wicket viewer.
BrixCMS also uses factories to create tiles.

Martin Grigorov
Wicket Training and Consulting
https://twitter.com/mtgrigorov

On Thu, Feb 18, 2016 at 7:21 AM, Arjun Dhar <dh...@yahoo.com> wrote:

> Hi,
> I have a bunch of Admin panels but i want to be able to override them. The
> issue is the pages obviously use "add(new SomeAdminPanel(....))";
>
> To overcome this I was thinking or writing a Factory, that via can create
> the desired instance of the Panel and pass it to the Page. The factory
> internally can use Spring to make this highly configurable.
>
> however, I came across
>
> https://ci.apache.org/projects/wicket/guide/6.x/guide/bestpractices.html#bestpractices_12
> (Do not use factories for components)
>
> ... can anyone validate if I should let that stop me from doing what I
> intend? Maybe Panels are an exception to this rule?!
>
> thanks
>
> -----
> Software documentation is like sex: when it is good, it is very, very
> good; and when it is bad, it is still better than nothing!
> --
> View this message in context:
> http://apache-wicket.1842946.n4.nabble.com/Use-a-Factory-to-create-a-Panel-Yay-or-Nay-tp4673622.html
> Sent from the Users forum mailing list archive at Nabble.com.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>