myfaces-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Arash Rajaeeyan" <arash.rajaee...@gmail.com>
Subject Re: Option for NavigationHandler to support viewIds as outcome
Date Mon, 30 Oct 2006 13:30:09 GMT
Hi Martin,
may be this feature is very good for highly professional developer like you,
but consider those developers new in JSF.

what is the different between this and using forward and redirect methods,
from developer point of view? (not considering JSF life cycle problems)

(if a developer uses forward and direct, then s/he is not even forced to
define a view for their page in facesconfig file! and he can use the same
methods he may already know from JSP/ Servlet)

I have seen lots of .net and JSP developers who were trying to use
navigation rules just the way as redirects. and complaining about how hard
is it in JSF to redirect into another page, (complex methods), I think this
is just as Craig says because they haven't understand the deep rationality
behind navigation mechanism yet, and this feature will help them never
understand it!

On 10/30/06, Martin Marinschek <martin.marinschek@gmail.com> wrote:
>
> Hi David,
>
> @breaking tool support: yes, that's true, and is something that might
> or might not be of interest to developers.
>
> @application size: For an application with 2000 views, we're
> definitely talking about large-size here. I'm absolutely d'accord that
> for a large size applications with a high number of developers
> assigned to them the normal navigation system should be used.
>
> Having the option of not using the default navigation system for
> small, simple applications is something positive, though.
>
> regards,
>
> Martin
>
> On 10/30/06, David Chandler <david.chandler@learnjsf.com> wrote:
> > Don't forget that returning view IDs in outcomes will break tool support
> > such as the visual page flow designer in Exadel Studio. Even without
> tools,
> > I find it extremely helpful as a developer to be able to look in one
> place
> > to see how the application flows. The proposed capability would make
> that
> > impossible, so I agree with Craig and Arash that returning view IDs in
> > outcomes is unsuitable for apps that will be maintained by multiple
> > developers.
> >
> > Having worked as one of 30+ developers on a large application (2000
> views)
> > written in a scripting language that effectively returned view IDs in
> > outcomes, I can testify to the horrors of code maintenance with this
> > approach. Introducing finite state machine navigation into that code
> base
> > and moving nav rules to config files has made it much easier to work on.
> >
> > David Chandler
> > JSF Consultant / Trainer
> > learnjsf.com
> >
> >
> > On 10/30/06, Arash Rajaeeyan < arash.rajaeeyan@gmail.com> wrote:
> > > It is much easier for a developer (especially if they are beginners in
> > JSF) to return name of the page instead of event occurred in page
> (logical
> > outcome) as output.
> > >
> > >
> > > There are some bad development practices, which when a developer get
> used
> > to them, it is hard to forget, I think this feature is one of them.
> > >
> > > since this bad practice(same reasons as described by Craig), makes
> life
> > easier for them, when they have this feature they will get addicted to
> it,
> > and they won't learn the real idea behind outcomes.
> > >
> > >
> > > I think this is like giving marijuana to JSF developers! Like the
> cartoon
> > in the theserverside.com about AOP considered harmful ;-) Regards
> > > Arash
> > >
> > >
> > >
> > > On 10/30/06, Martin Marinschek < martin.marinschek@gmail.com> wrote:
> > > > Hi Craig,
> > > >
> > > > It's all about convention over configuration, and this concept is in
> > > > turn very good for maintenance. Writing unnecessary configuration
> code
> > > > isn't.
> > > >
> > > > Let's look at an automatic navigation handler in practice:
> > > >
> > > > 1) I have a managed-bean action-method which returns "overview" and
> > > > this means, I'll go to overview.jsp
> > > >
> > > > 2) I want to change this to go to "overview_2.jsp"
> > > >
> > > > 3) so I won't change anything in the managed-bean-method, but create
> a
> > > > new navigation-rule (in your case, I'd need to change the
> > > > navigation-rule - where is the maintenance difference, I don't touch
> > > > my managed-bean?)
> > > >
> > > > 4) If I want to go to somewhere else from any other page, I'll need
> to
> > > > create additional navigation-rules, according to the concept of JSF.
> > > >
> > > > Essence is - you don't have to change anything in your managed bean,
> > > > you  just add configuration rules where necessary, but keep them out
> > > > where unnecessary.
> > > >
> > > > regards,
> > > >
> > > > Martin
> > > >
> > > > On 10/30/06, Craig McClanahan <craigmcc@apache.org > wrote:
> > > > >
> > > > >
> > > > > On 10/30/06, Martin Marinschek < martin.marinschek@gmail.com>
> wrote:
> > > > > > Hi Craig,
> > > > > >
> > > > > > you have been argumenting into this direction before, and I'm
> sorry
> > to
> > > > > > disagree completely. What JSF does in the standard is good for
> > > > > > projects where you have this necessity of different roles for
> page
> > > > > > development and back-end development.
> > > > >
> > > > > It's not a matter of different roles.  The design principles I
> > advocate are
> > > > > the same whether there is one developer performing multiple roles,
> or
> > > > > different developers (or developer groups) performing the
> different
> > roles.
> > > > >
> > > > > The architectural issues here are exactly the same in either case.
> > > > >
> > > > > > Generally - for small projects, and the majority of web-projects
> are
> > > > > > still small projects, the person writing the navigation-handling
> > code,
> > > > > > the page, and the backing-bean will be the same, so why not
give
> > them
> > > > > > the ability to have a convention-over-configuration approach?
> You
> > can
> > > > > > always override convention-over-configuration by supplying
> > > > > > configuration!
> > > > >
> > > > > Because that user will be crying alligator tears a year from now,
> or a
> > month
> > > > > from now, when the person responsible for the overall organization
> of
> > the
> > > > > webapp changes the set of view identifiers that represents the UI
> of
> > an app.
> > > > >  WHY SHOULD THIS REQUIRE CHANGES IN THE BUSINESS LOGIC???.  That
> is a
> > > > > cross-linkage between view tier and model tier that I find
> > unacceptable in
> > > > > large scale apps.
> > > > >
> > > > > You have a seductive argument with respect to small scale
> apps.  But I
> > can
> > > > > tell you from 30 years of professional software development
> experience
> > that
> > > > > managers tend to buy in to this kind of attitude at the prototype
> > stage,
> > > > > when ongoing application maintenance is not a consideration.  And
> > those
> > > > > types of people tend to be really unhappy when the effects of this
> > type of
> > > > > decision cause their maintenance budgets to skyrocket.  The scale
> of
> > the app
> > > > > does not actually matter -- the percentage of the overall budget
> that
> > must
> > > > > be allocated to reworking previously running code is *always* a
> major
> > > > > consideration.
> > > > >
> > > > > > Furthermore, I seem to resemble that in the discussion about
> > > > > > annotations you've made the same proposal as Ernst has at the
> > > > > > beginning of this discussion - writing a custom
> navigation-handler
> > > > > > which enables one to optionally not configure navigations, and
> not
> > > > > > handle navigation via annotations.
> > > > >
> > > > > I am *adamantly* in the "no annotations for navigaiton" camp ...
> > navigation
> > > > > is absolutely *not* something that should be done with
> annotations.
> > Doing
> > > > > so would have the same effect as implementing the suggested
> approach
> > -- it
> > > > > would be requiring the person developing the server side business
> > logic to
> > > > > be intimately aware of view tier considerations like "what view
> should
> > I
> > > > > show next?".
> > > > >
> > > > > Doing so makes it basically impossible to reuse business logic in
> > scenarios
> > > > > like:
> > > > >
> > > > > * Migrating a non-AJAX app to be AJAX-enabled
> > > > >
> > > > > * Using the same business logic for REST-based or SOAP-based
> > > > >   web services
> > > > >
> > > > > In short, I believe that requiring the developer of an action
> method
> > to know
> > > > > anything about what the view tier will do next is a ***very*** bad
> > idea.
> > > > >
> > > > > You might note that the Shale Tiger Extensions have no provision
> for
> > > > > annotation based navigation.  That is a deliberate design choice,
> not
> > one
> > > > > based on limited development time :-)
> > > > >
> > > > > > regards,
> > > > > >
> > > > > > Martin
> > > > >
> > > > >
> > > > > Craig
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > >
> > > > http://www.irian.at
> > > >
> > > > Your JSF powerhouse -
> > > > JSF Consulting, Development and
> > > > Courses in English and German
> > > >
> > > > Professional Support for Apache MyFaces
> > > >
> > >
> > >
> > >
> > > --
> > > Arash Rajaeeyan
> >
> >
> >
> > --
> > http://learnjsf.com
>
>
> --
>
> http://www.irian.at
>
> Your JSF powerhouse -
> JSF Consulting, Development and
> Courses in English and German
>
> Professional Support for Apache MyFaces
>



-- 
Arash Rajaeeyan

Mime
View raw message