Create nodes in KNIME 4.0

KNIME Development
#1

Hello!
I need to create nodes to be used in KNIME 4.0.2. I already created those nodes for KNIME 4.5.2 but it seams to not be backwards compatible.
So I tried to do your tutorial, but it did not work with the Number Formatter node for KNIME 4.0.2 (I put Java 8 and the 2019-06 release).
It raises the following error:

ERROR	 Worker-1 RepositoryManager	 Node org.knime.examples.numberformatter.NumberFormatterNodeFactory' from plugin 'org.knime.examples.numberformatter' could not be created: Can't load factory class for node: org.knime.examples.numberformatter.NumberFormatterNodeFactory The corresponding plugin bundle could not be activated!

Do you know how I should do to create a node for this version (if it is possible)? Thank you in advance!

Best,
Aidan

#2

Hi @aidandng,

Take a look into the KNIME log (make sure you have debug logging turned on), it should tell you why the activation failed (most likely an issue with the wrong dependencies or it trying to load classes that don’t exist.

best,
Gabriel

#3

Hello @gab1one

Thanks for your answer.
I already turn on the debug logging to see why the Number Formatter node can not be loaded. Here is the log before and after the error:

DEBUG RepositoryManager               Found node extension 'org.knime.ensembles.pmmlpredict3.PMMLPredictorNodeFactory3': PMML Predictor
DEBUG RepositoryManager               Found node extension 'org.knime.ensembles.pmml.predictor3.PMMLEnsemblePredictorNodeFactory3': PMML Ensemble Predictor
ERROR RepositoryManager               Node org.knime.examples.numberformatter.NumberFormatterNodeFactory' from plugin 'org.knime.examples.numberformatter' could not be created: Can't load factory class for node: org.knime.examples.numberformatter.NumberFormatterNodeFactory The corresponding plugin bundle could not be activated!
DEBUG RepositoryManager               Found node extension 'org.knime.explorer.nodes.callworkflow.local.CallLocalWorkflowNodeFactory': Call Local Workflow (Row Based)
DEBUG RepositoryManager               Found node extension 'org.knime.explorer.nodes.browser.ExplorerBrowserNodeFactory': Explorer Browser

The others lines shows that it has found others nodes. If you have any others ideas, I will test them!

Best,
Aidan

#4

I finally found the origin of the error. Eclipse indicate that, if I use Java 8, I must use the proper compiler (here, the compiler 1.8).

Thanks for your help!

Best,
Aidan

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#5

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