No corresponding property found for constructor parameter nodes

[tom91136]

I want to make my data immutable so this is what I did:

....
private final HashMap<String, Bundle> nodes;
....

@ParcelConstructor
 NavigationPath(HashMap<String, Bundle> nodes) {
    this.nodes = nodes;
}

 HashMap<String, Bundle> getNodes() {
    return nodes;
}

Notice that the constructor and getter for node is package private.

This exception is thrown when compiling:

NavigationPath.java:40: error: Parceler: No corresponding property found for constructor parameter     nodes
 NavigationPath(HashMap<String, Bundle> nodes) {

If I make the methods/constructors public, then I loose immutability.
Can you make parceler support at least package private visibility?
Butterknife does that without problems so I assume this can be done?

[johncarl81]

Parceler supports all modifiers, including package private (FYI, regular-private is discouraged as it uses reflection).

What version are you using? Are you using @Parcel(Parcel.Serialization.METHOD) or @Parcel(Parcel.Serialization.FIELD)?

[tom91136]

I'm using @Parcel(Serialization.METHOD)
After some testing, constructor works fine but not the getters:

Works:

@ParcelConstructor
 NavigationPath(HashMap<String, Bundle> nodes) {
    this.nodes = nodes;
}
public HashMap<String, Bundle> getNodes() {
    return nodes;
}

Doesn't work:

@ParcelConstructor
 NavigationPath(HashMap<String, Bundle> nodes) {
    this.nodes = nodes;
}

HashMap<String, Bundle> getNodes() {
    return nodes;
}

Can package private be supported without using reflection?

[johncarl81]

Yes, package private should be supported without reflection. Let me investigate a bit...

[tom91136]

That would be awesome! thanks

[johncarl81]

@tom91136, Finally got to the bottom of this. Are you seeing this NPE also?:

Exception in thread "pool-3-thread-1" java.lang.NullPointerException
    at org.parceler.internal.ParcelableGenerator.buildWriteToParcel(ParcelableGenerator.java:286)
    at org.parceler.internal.ParcelableGenerator.buildParcelWrite(ParcelableGenerator.java:191)
    at org.parceler.internal.ParcelableGenerator.generateParcelable(ParcelableGenerator.java:101)
    at org.parceler.internal.ParcelTransactionWorker.innerRun(ParcelTransactionWorker.java:53)
    at org.parceler.internal.ParcelTransactionWorker.innerRun(ParcelTransactionWorker.java:34)
    at org.parceler.transfuse.transaction.AbstractCompletionTransactionWorker.run(AbstractCompletionTransactionWorker.java:35)
    ...

Remembering the thoughts behind METHOD serialization, this feature follows the java bean standard, which specifies that getters and setters must be named a certain way have certain parameters and return types, and be public.

This is a problem in the library, however. I'm thinking that 1. this should be flagged as an error, because Parceler cannot find a valid getter and 2. Should be overrideable with an annotation, so this should work:

@Parcel(Parcel.Serialization.METHOD)
public class NavigationPath {

    private final HashMap<String, Bundle> nodes;

    @ParcelConstructor
    NavigationPath(HashMap<String, Bundle> nodes) {
        this.nodes = nodes;
    }

    @ParcelProperty("nodes")
    HashMap<String, Bundle> getNodes() {
        return nodes;
    }
}

Thoughts?

[tom91136]

Yes that's the exact stacktrace I got
that looks like a pretty good solution to me
also, if a field/method is annotated properly, suppress the warning (or with an annotation like @Suppress)

[johncarl81]

@tom91136, Both of these cases are implemented and your example should work now with the getNodes() method annotated with @ParcelProperty("nodes"). I've deployed this under 0.2.11-SNAPSHOT to Maven central and pushed to 94cb848. Let me know if this works for you.

[tom91136]

Works great! thanks