iPOJO, problems with @Controller and @ServiceController

[Bengt Rodehav]

I discussed this with Clement on another thread ("iPOJO and dynamic
requires") but thought I'd start a new thread that better describes the
subject.

A little background...

Using iPOJO (currently 1.8.6), I have a system where I'm using a
life-cycle-controller (@Controller) to enable(start) / disable(stop) my
services. A lot of the services are Camel routes that are then started and
stopped by changing a config admin property (in a GUI).

Basically the code looks like this:

  @Controller
  @Property(name = "enabled", mandatory = true, value = "false")
  private boolean mValid;

  @Validate
  public void start() {
    System.out.println("Starting... valid is: " + mValid);
    // Start the Camel route
  }

  @Invalidate
  public void stop() {
    System.out.println("Stopping... valid is: " + mValid);
    // Stop the Camel route
  }

On startup, if the "enabled" property is set to false, nothing is logged.
When I set the enabled property to true I get:

  Starting... valid is: true

If I then set the enabled property to false I get:

  Stopping... valid is: false

This is the way I want it to work. I use the "enabled" property to
start/stop my services.

However, I now need to make the life-cycle controller more dynamic. In
addition to looking at the "enabled" property I also want to add my custom
extra constraints. Something like this:

  private boolean mValid;

  @Property(name = "enabled", mandatory = true, value = "false")
  public void setValid(boolean theValid) {
    System.out.println("Setting valid to: " + theValid);
    mValid = theValid;
    mAggregateValid = mValid; // I also add extra constraints not shown
here: mAggregateValid = mValid && <extra constraints>
  }

  @Controller
  private boolean mAggregateValid;

  @Validate
  public void start() {
    System.out.println("Starting... mValid is: " + mValid + ",
mAggregateValid is: " + mAggregateValid);
    // Start the Camel route
  }

  @Invalidate
  public void stop() {
    System.out.println("Stopping... mValid is: " + mValid + ",
mAggregateValid is: " + mAggregateValid);
    // Stop the Camel route
  }

I now get:

  Starting... mValid is: false, mAggregateValid is: false
  Stopping... mValid is: false, mAggregateValid is: false

This is not the way I wanted. Although I've set the @Controller to
"mAggregateValid", the instance is becoming valid when the mAggregateValid
is false. It does stop shortly afterwards but I get a false start this way
that gives me problems.

Question 1: Why does the instance become valid despite the fact that my
life-cycle-controller is false?

Clement, you suggested that I should use the @ServiceController instead. I
tried this but it seems like the @Validate callback will be called no
matter what value my @ServiceController has. I noticed that there are other
callbacks that I might be able to use instead: @PostRegistration and
@PostUnregistration. However, they seem to be called "after the fact". If I
use those callbacks to actually start my services it would mean that I
first publish a service and afterwards make it work. Should be the other
way around.

Question 2: For my use case, should I use @Controller or @ServiceController

Looking at the annotations documentation (
http://felix.apache.org/documentation/subprojects/apache-felix-ipojo/apache-felix-ipojo-gettingstarted/how-to-use-ipojo-annotations.html)
I noticed that @Controller is not mentioned at all.

Question 3: Is @Controller deprecated or does the documentation need to be
updated?

When the new version of iPOJO is released I might not need to use an
"aggregated controller" but could use interceptors instead (see my original
thread). But I would still like to know why I can't get the above to work
correctly.

Thanks,

/Bengt