Whew...emails like mine always come out when you are rushing to get on the
plane...
Those are good thoughts on design intent. Its really a question of where
you force users to encounter this complexity. Where you force complexity
/flexibility to be dealt with (the boundary line) is based on how you think
the market responds to these choices and where you wish to lay claim to
differentiation.
I thought about my email after I sent it and wondered where the changes
really needed to go. I spent a few minutes making some changes to the
Component class and was able to allow it to set style properties at any
parent object and have it flow appropriately to every component of a certain
type below it in the tree automatically--no changes to the serializer. It's
not production quality and requires more thought, but its illustrative. I
was of course fortunate that the pivot code base is good as it took longer
to write the email than it did to change the code.
<Frame ...>
<userData org.apache.pivot.wtk.TreeView="{showEmptyBranchControls: false}"
org.apache.pivot.wtk.Border="{backgroundColor:null, padding:2}"/>
<content stuff here>
<MyTreeView ... /> <!-- Styles auto-applied here based on
the class type, but any key could work. In this example, all TreeViews will
have the same style automatically -->
</content stuff here>
</Frame>
Of course, there are different ways I could set styles including
subclassing, setting the skin or repeating styling info. I have to subclass
for the data management part (no way around that a lot of times) but this
was easy and consistent with pivot syntax and keeps it out of my value-add
work around domain data.
I also tested the Initializer (which I called ComponentExtensionLifecycle
after seeing another pivot class with a similar name) thing to the user data
and the proof point was that I was able to send EventBus messages from the
component class for selection classes per bushe's blog I saw somewhere all
as a service. Since it's a component service...add it if you want,
otherwise skip it by not adding it to your user data. I was able to extend
behavior through composition and its highly reusable by others. For managing
the selection coming from anywhere in my application, this is a good thing.
I did not do the menu idea because I am still having trouble with the menu
syntax. Without element-map, I had to add it in code but the idea is the
same. It needs more thinking but showed potential for extension through
composition and services. I was bit surprised it worked the first time but
it needs some more proof points. I'll add the menu thing next to determine
real reusability.
It was not a lot of change to demonstrate the use cases all without script.
Getting the hierarchical resources right may require more thought of course
so you never have to change the basics infrastructure again the future. I
was wrong about the serializer needing changes except needing element-map
support. But Component had some minor changes.
-----Original Message-----
From: Greg Brown [mailto:gkbr...@mac.com]
Sent: Friday, June 11, 2010 5:08 PM
To: aappddeevv; dev@pivot.apache.org
Subject: Re: [jira] Updated: (PIVOT-514)
This all sounds quite interesting, but may be a bit more than we want or
need WTKXSerializer to do. Using the existing implementation you can
delegate a lot of what you are proposing to Java or script. I'm extremely
wary of making WTKXSerializer more complex than it needs to be, especially
since we haven't run into a real use case for a lot of this stuff. It makes
it harder to maintain the code and harder for users to understand.
----- Reply message -----
From: "aappddeevv" <aappdde...@verizon.net>
Date: Fri, Jun 11, 2010 12:26 pm
Subject: [jira] Updated: (PIVOT-514)
To: <dev@pivot.apache.org>
Yes, this is very cool. My collection comment on this issue was purely what
interface is used to detect a call to add(). Declarative programming is an
important option for pivot clients and more importantly, has great tooling
potential.
Just thinking out loud...and typing fast...
Related to maps, probably one good user XML extension for the serializer and
that has a lot of uses cases is to specify a map as elements versus
attributes. Also, through more annotation magic, the default key generator
can be specified. Many lookups occur using a class (name) as a lookup key or
the key is easily statically specified by the object or its static nature.
The "elements vs attributes" approach allows you to specify the object
instance inline because specifying an object class to be instantianted in an
attribute value is ambiguous unless you add more DSL (e.g. instead of a $
for a reference lookup, a % for an object creation).
This allows me to specify a bunch of objects without always having to use
attributes. The object can be defined and instantiated inline for the map
versus referenced elsewhere. There are 2-3 major use cases for this e.g.
automated menu population/configuration. And by establishing a very small
convention, allows a large number of declarative processing scenarios that
create new class behaviors without subclassing/coding. This is the true
power of the serializer/component as a container thinking and doesn't put
too much burden on the serializer (i.e. avoiding full DI-container semantics
which is a lot of work to create and is not needed here).
However, this is not compelling enough yet to suggest unless other pivot
elements (those 2-3 uses cases) are also enabled.
For example, as a small convention with support, if the serializer
automatically scans the user data and finds an object with an
interface/annotation called "Initializer", the interface is called. This
initialize can in turn scan the user data for a menu specification and
automatically add or substract a menu (also in the user data) from the main
menu when the component has focus (or whatever). By combining this with
Component's "name", I can specify the attach point as a menu URL. This is
Component-level services configured at the Component level and entirely
optional all without subclassing in my application---I just write services
that are reusable and use composition to create new behaviors. All of this
has minimal API impact (almost none) but does need a small amount of
pivot-library level support. Any Component can be a menu contributor.
If we add cross-tree hierarchical user data lookup (minimal API impact) and
object initialization lifecycle event signaling (some API impact), you have
ingredients to create significant defaulting and user data management
behaviors. This would help with additional application-level, declarative
thematic and stylizing defaulting. By using JSON for style specifications,
which I think is clever, combined with a defaulting system that is
cross-tree, you have a nice set of customization capabilities that reduces
the experience level needed to create great looking applications, avoids
coding (subclassing or using code to configure), enables easier tooling and
can employ declarative configuration for those that like it. Conceptually,
this is at the heart of managing the boundary between coding and
configuration in a *balanced* way.
So in this area (element map, small "initializer" interface, cross-tree user
data lookup, contract for object creation/initialization), plus a little
convention enables a lot of flexibility and to Dirk's point, doesn't box you
in. This is an unique, targeted fusion of WPF and eclipse e4 thinking that
could be possible in pivot. I don't know enough about Adobe and other
frameworks to say how they handle complexity and flexibility.
-----Original Message-----
From: Greg Brown [mailto:gkbr...@mac.com]
Sent: Friday, June 11, 2010 9:14 AM
To: dev@pivot.apache.org
Subject: Re: [jira] Updated: (PIVOT-514)
I should add that WTKXSerializer *does* actually know about maps (or, more
specifically, dictionaries). If your class exposes a read-only dictionary
property (e.g. Component#getUserData()), WTKXSerializer will properly
populate the dictionary based on markup. For example:
<Window>
<userData foo="abc" bar="$def"/>
</Window>
The serializer will effectively call getUserData().put("foo", "abc") and
getUserData().put("bar", def), where def is the value of the page-scoped
variable referred to by "def". This is what allows styles to be set using an
element vs. a JSON string, for example:
<Label>
<styles color="#ff0000"/>
</Label>
vs.
<Label styles="{color:'#ff0000'}">
WTKXSerializer caters to sequences and dictionaries because those are the
structures employed by XML. An XML element is effectively both a sequence
(containing sub-elements and text nodes) and a dictionary (mapping string
attribute names to attribute values). Since sets aren't really used by XML,
there's no need for WTKXSerializ
