THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
How
...
does
...
Tuscany
...
start
...
components
...
from
...
a
...
contribution?
...
Contributed
...
by
...
Giorgio
...
Zoppi
...
<giorgio.zoppi@gmail.com>
...
This
...
document
...
describes
...
how
...
a
...
composite
...
file
...
(i.e.
...
MyComposite.composite)
...
gets
...
processed
...
for
...
a
...
simple
...
composite.
...
When
...
the
...
XML
...
parser
...
sees
...
a
...
composite
...
element,
...
create
...
a
...
composite,
...
it
...
checks
...
if
...
it
...
is
...
autowired
...
and
...
if
...
it
...
has
...
an
...
item
...
autowire,
...
it
...
sets
...
the
...
composite
...
to
...
be
...
autowired,
...
then
...
it
...
checks
...
if
...
it's
...
local
...
and
...
if
...
it
...
has
...
constrainting
...
types.
...
If
...
the
...
composite
...
has
...
constrainting
...
types,
...
they
...
are
...
processed.
...
Then
...
the
...
parser
...
reads,
...
if
...
they
...
are
...
present,
...
the
...
policies
...
for
...
the
...
composite.
...
Suppose
...
that
...
in
...
my
...
simple
...
example
...
i
...
have
...
no
...
constrain
...
or
...
policy.
...
At
...
a
...
given
...
point
...
the
...
parser
...
sees
...
an
...
<component>
...
item,
...
in
...
this
...
case,
...
the
...
runtime:
...
- It creates a RuntimeComponent by the RuntimeComponentFactory,
sets its name, it looks if the component needs to be autowired,
then it checks if it has constrainting types. If the composite has
constrainting types, they are processed.
Then the parser reads, if they are present, the policies for the component.
At other point the runtime sees an extension point, which it could be
a service, a binding, an implementation type and so on..In this
document we suppose, that the runtime sees:
<implementation.java .....>
The runtime at this point gets the extension processor. The extension
processor has in input the component, and the reader from the XML
Parser. From the XML document, the extension processor recognize the
extension type and it gets the needed factory.
For example, inside the read method of JavaImplementationProcessor we have:
JavaImplementation javaImplementation = javaFactory.createJavaImplementation();
javaImplementation.setUnresolved(true);
...
From
...
the
...
CLASS
...
attribute,
...
the
...
runtime
...
understand
...
the
...
kind
...
of
...
interface.
| Code Block |
|---|
javaImplementation.setName(reader.getAttributeValue(null, CLASS)); |
Then
...
it
...
reads
...
the
...
policies:
| Code Block |
|---|
// Read policies policyProcessor.readPolicies(javaImplementation, reader); // Skip to end element while (reader.hasNext()) { if (reader.next() == END_ELEMENT && IMPLEMENTATION_JAVA_QNAME.equals(reader.getName())) { break; } } return javaImplementation; |
At
...
this
...
point,
...
the
...
runtime
...
adds
...
the
...
implementation
...
to
...
the
...
component
...
with:
| Code Block |
|---|
component.setImplementation(...) |
and
...
it
...
adds
...
the
...
component
...
to
...
the
...
composite.
...
Until
...
now
...
we're
...
processing
...
a
...
MyComposite.composite
...
like
...
this:
| Code Block |
|---|
<composite> <component name="MyName"> <implementation.java class="package.MyClass"/> </component> </composite> |
Suppose
...
now
...
to
...
find
...
a
...
service(<service>)
...
item,
...
what
...
happens?
...
The
...
runtime:
...
- creates
...
- a
...
- RuntimeComponentService
...
- sets
...
- the
...
- Contract
...
- (service
...
- contract)
...
- to
...
- RuntimeComponentService
...
- sets
...
- RuntimeComponentService's
...
- name
...
- adds
...
- RuntimeComponentService
...
- instance
...
- to
...
- Component's
...
- Services.
...
- it
...
- seeks
...
- for
...
- services
...
- policies.
...
Now
...
a
...
service
...
has
...
an
...
interface
...
(<interface>),
...
and
...
it
...
could
...
be
...
a
...
java
...
interface.
...
At
...
this
...
point
...
the
...
runtime
...
creates
...
a
...
JavaInterfaceContractImpl
...
by
...
a
...
JavaInterfaceFactory
...
and
...
sets
...
it
...
to
...
the
...
service
...
contract
...
(call:
...
contract.setInterfaceContract(...)).
...