streampipes-pipeline-elements-examples-processors-jvm/src/main/java/org/apache/streampipes/pe/examples/jvm/staticproperty/MultiValueSelectionExampleController.java

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 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
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 *    http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.streampipes.pe.examples.jvm.staticproperty;

import org.apache.streampipes.model.graph.DataProcessorDescription;
import org.apache.streampipes.model.graph.DataProcessorInvocation;
import org.apache.streampipes.pe.examples.jvm.base.DummyEngine;
import org.apache.streampipes.pe.examples.jvm.base.DummyParameters;
import org.apache.streampipes.sdk.builder.ProcessingElementBuilder;
import org.apache.streampipes.sdk.builder.StreamRequirementsBuilder;
import org.apache.streampipes.sdk.extractor.ProcessingElementParameterExtractor;
import org.apache.streampipes.sdk.helpers.EpRequirements;
import org.apache.streampipes.sdk.helpers.Labels;
import org.apache.streampipes.sdk.helpers.Options;
import org.apache.streampipes.sdk.helpers.OutputStrategies;
import org.apache.streampipes.sdk.helpers.SupportedFormats;
import org.apache.streampipes.sdk.helpers.SupportedProtocols;
import org.apache.streampipes.wrapper.standalone.ConfiguredEventProcessor;
import org.apache.streampipes.wrapper.standalone.declarer.StandaloneEventProcessingDeclarer;

import java.util.List;

public class MultiValueSelectionExampleController extends StandaloneEventProcessingDeclarer<DummyParameters> {

  @Override
  public DataProcessorDescription declareModel() {
    return ProcessingElementBuilder.create("org.apache.streampipes.examples.staticproperty" +
            ".multivalue", "Multi value selection example", "")
            .requiredStream(StreamRequirementsBuilder.
                    create()
                    .requiredProperty(EpRequirements.anyProperty())
                    .build())
            .outputStrategy(OutputStrategies.keep())
            .supportedProtocols(SupportedProtocols.kafka())
            .supportedFormats(SupportedFormats.jsonFormat())

            // create a simple text parameter
            .requiredMultiValueSelection(Labels.from("id", "Example Name", "Example " +
                    "Description"), Options.from("Value A", "Value B", "Value C"))

            .build();
  }

  @Override
  public ConfiguredEventProcessor<DummyParameters> onInvocation(DataProcessorInvocation graph, ProcessingElementParameterExtractor extractor) {

    // Extract the text parameter value
    List<String> selectedSingleValue = extractor.selectedMultiValues("id", String.class);

    // now the text parameter would be added to a parameter class (omitted for this example)

    return new ConfiguredEventProcessor<>(new DummyParameters(graph), DummyEngine::new);
  }
}