On 30/09/2011 08:39, Christophe Dehlinger wrote:
Hello,
Hi Christophe, thanks for your interest.
I'm currently evaluating isis for a new application. One of the requirements
is that users should be able to import and export data as spreadsheets.
There doesn't seem to be file choosing views shipped with the dnd viewer, so
I've been trying to roll out my own (the usual pair of a text field and
button that opens a file chooser). Unfortunately, I got overwhelmed by all
the concepts involved (views, view requirements, factories,
These classes relate to the DnD viewer itself, and I can't help you out
very much since I didn't write the DnD viewer. I can point you to the
(incomplete) notes in the DnD guide [1]; but I've asked Rob Matthews
(who was the author of the Dnd viewer) if he can reply more fully.
specifications
and builders, facets and their factories, object adapters, the various
contexts...) and their relations, and ultimately have been unabled to get
anything working so far.
I can help you a little more here, as these are the classes that belong
to the core framework. The break into two:
a) the specifications (ObjectSpecification), Facet and FacetFactory are
part of the metamodel. You can think of ObjectSpecification as
equivalent to java.lang.Class, while Facet is a piece of metadata
associated with a class. There is also ObjectMember; facets can be
associated with these two.
This stuff is reasonably well documented in [2].
b) the ObjectAdapter is a runtime wrapper around a pojo, so is broadly
equivalent to java.lang.Object. Every ObjectAdapter references its
corresponding ObjectSpecification (just as every Java object knows its
runtime class).
Isis supports the notion of pluggable runtimes, but there is currently
only one runtime, the "default runtime". It's implementation is
reasonably well documented in [3].
Also, the app will be deployed in client/server mode, and I can't figure out
whether domain object methods are run on the server or on the client.
You should know that, even though the largest system built using (the
precursor to) Isis does use the client/server configuration, these days
I wouldn't necessarily recommend it as a deployment approach. The issue
with the design is that the garbage collection of object adapters is not
particularly well-defined. Instead, you might want to consider one of
the webapp viewers.
But, to answer your question... by default domain object methods by
default run on the server if the object is persistent, but are run on
the client if the object is transient. However, this can be overridden
using the @Executed(Where) annotation (Where.LOCALLY=on the client,
Where.REMOTELY=on the server).
As a
consequence, I don't know whether the argument to the import action should
be a reference to the file (a la java.io.File) or its contents (a wrapper on
byte[]).
You could do this by having a object with an action taking a simple
string, being the name of the file. (As you say, it'd be better if the
DnD viewer had a file chooser dialog for this, and Rob might be able to
say how to do this). But in terms of the domain object model, it'd just
be a filename.
Another option might be to use the @Value annotation to instruct Isis
that a java.io.File is a value type. There's coverage of this in the
applib guide [4].
Hope that all helps a little,
Dan
I'd be grateful if someone could give me a summary of the classes I have to
implement.
Thanks,
Christophe
[1] http://incubator.apache.org/isis/viewer/dnd/docbkx/html/guide/ch04.html
[2] http://incubator.apache.org/isis/core/docbkx/html/guide/isis-core.html
[3]
http://incubator.apache.org/isis/runtimes/dflt/docbkx/html/guide/ch05.html
[4] http://incubator.apache.org/isis/applib/docbkx/html/guide/ch10.html
