feat: add a new radar chart operator

common/workflow-operator/src/main/scala/org/apache/texera/amber/operator/LogicalOp.scala

@@ -124,6 +124,7 @@ import org.apache.texera.amber.operator.visualization.nestedTable.NestedTableOpD
 import org.apache.texera.amber.operator.visualization.networkGraph.NetworkGraphOpDesc
 import org.apache.texera.amber.operator.visualization.pieChart.PieChartOpDesc
 import org.apache.texera.amber.operator.visualization.quiverPlot.QuiverPlotOpDesc
+import org.apache.texera.amber.operator.visualization.radarChart.RadarChartOpDesc
 import org.apache.texera.amber.operator.visualization.rangeSlider.RangeSliderOpDesc
 import org.apache.texera.amber.operator.visualization.sankeyDiagram.SankeyDiagramOpDesc
 import org.apache.texera.amber.operator.visualization.scatter3DChart.Scatter3dChartOpDesc
@@ -190,6 +191,7 @@ trait StateTransferFunc
     new Type(value = classOf[RangeSliderOpDesc], name = "RangeSlider"),
     new Type(value = classOf[PieChartOpDesc], name = "PieChart"),
     new Type(value = classOf[QuiverPlotOpDesc], name = "QuiverPlot"),
+    new Type(value = classOf[RadarChartOpDesc], name = "RadarChart"),
     new Type(value = classOf[WordCloudOpDesc], name = "WordCloud"),
     new Type(value = classOf[HtmlVizOpDesc], name = "HTMLVisualizer"),
     new Type(value = classOf[UrlVizOpDesc], name = "URLVisualizer"),

common/workflow-operator/src/main/scala/org/apache/texera/amber/operator/visualization/radarChart/RadarChartOpDesc.scala

@@ -0,0 +1,166 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more 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 the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.texera.amber.operator.visualization.radarChart
+
+import com.fasterxml.jackson.annotation.{JsonProperty, JsonPropertyDescription}
+import com.kjetland.jackson.jsonSchema.annotations.{JsonSchemaInject, JsonSchemaTitle}
+import org.apache.texera.amber.core.tuple.{AttributeType, Schema}
+import org.apache.texera.amber.core.workflow.OutputPort.OutputMode
+import org.apache.texera.amber.core.workflow.{InputPort, OutputPort, PortIdentity}
+import org.apache.texera.amber.operator.PythonOperatorDescriptor
+import org.apache.texera.amber.operator.metadata.annotations.{
+  AutofillAttributeName,
+  AutofillAttributeNameList
+}
+import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
+import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
+import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
+import org.apache.texera.amber.pybuilder.PythonTemplateBuilder.PythonTemplateBuilderStringContext
+
+import javax.validation.constraints.NotNull
+
+// type constraint: value can only be numeric
+@JsonSchemaInject(json = """
+{
+  "attributeTypeRules": {
+    "valueColumns": {
+      "enum": ["integer", "long", "double"]
+    }
+  }
+}
+""")
+class RadarChartOpDesc extends PythonOperatorDescriptor {
+
+  @JsonProperty(value = "nameColumn", required = true)
+  @JsonSchemaTitle("Name Column")
+  @JsonPropertyDescription("Column containing entity names for each radar")
+  @AutofillAttributeName
+  @NotNull(message = "Name column cannot be empty")
+  var nameColumn: EncodableString = ""
+
+  @JsonProperty(value = "valueColumns", required = true)
+  @JsonSchemaTitle("Value Columns")
+  @JsonPropertyDescription("Columns containing numeric values for radar chart axes")
+  @AutofillAttributeNameList
+  var valueColumns: List[EncodableString] = _
+
+  @JsonProperty(value = "fillOpacity", required = true)
+  @JsonSchemaTitle("Fill Opacity")
+  @JsonPropertyDescription(
+    "Opacity value for radar chart fill from 0.0 (transparent) to 1.0 (opaque)"
+  )
+  @JsonSchemaInject(json = """{ "minimum": 0.0, "maximum": 1.0, "default": 0.5 }""")
+  var fillOpacity: Double = 0.5
+
+  override def operatorInfo: OperatorInfo =
+    OperatorInfo(
+      "Radar Chart",
+      "Visualize data in a Radar Chart",
+      OperatorGroupConstants.VISUALIZATION_SCIENTIFIC_GROUP,
+      inputPorts = List(InputPort()),
+      outputPorts = List(OutputPort(mode = OutputMode.SINGLE_SNAPSHOT))
+    )
+
+  override def getOutputSchemas(
+      inputSchemas: Map[PortIdentity, Schema]
+  ): Map[PortIdentity, Schema] = {
+    val outputSchema = Schema()
+      .add("html-content", AttributeType.STRING)
+    Map(operatorInfo.outputPorts.head.id -> outputSchema)
+  }
+
+  def manipulateTable(): PythonTemplateBuilder = {
+    assert(nameColumn.nonEmpty)
+    assert(valueColumns != null && valueColumns.nonEmpty)
+    val valueColsList = valueColumns.map(col => pyb"""$col""").mkString(", ")
+    pyb"""
+       |        required_cols = [$nameColumn, $valueColsList]
+       |        table.dropna(subset=required_cols, inplace=True)
+       |        value_cols = [$valueColsList]
+       |        for col in value_cols:
+       |            table[col] = pd.to_numeric(table[col], errors='coerce')
+       |        table.dropna(subset=value_cols, inplace=True)
+       |"""
+  }
+
+  def createPlotlyFigure(): PythonTemplateBuilder = {
+    val valueColsList = valueColumns.map(col => pyb"""$col""").mkString(", ")
+    pyb"""
+       |        fig = go.Figure()
+       |        categories = [$valueColsList]
+       |
+       |        for idx, row in table.iterrows():
+       |            values = [row[col] for col in categories]
+       |            values.append(values[0])
+       |            categories_closed = categories + [categories[0]]
+       |
+       |            fig.add_trace(go.Scatterpolar(
+       |                r=values,
+       |                theta=categories_closed,
+       |                fill='toself',
+       |                name=str(row[$nameColumn]),
+       |                opacity=$fillOpacity
+       |            ))
+       |
+       |        fig.update_layout(
+       |            polar=dict(
+       |                radialaxis=dict(
+       |                    visible=True,
+       |                    range=[0, None]
+       |                )
+       |            ),
+       |            showlegend=True,
+       |            margin=dict(t=40, b=40, l=40, r=40)
+       |        )
+       |"""
+  }
+
+  override def generatePythonCode(): String = {
+    val finalcode =
+      pyb"""
+         |from pytexera import *
+         |
+         |import plotly.graph_objects as go
+         |import plotly.io
+         |import pandas as pd
+         |
+         |class ProcessTableOperator(UDFTableOperator):
+         |    def render_error(self, error_msg):
+         |        return '''<h1>RadarChart is not available.</h1>
+         |                  <p>Reason is: {} </p>
+         |               '''.format(error_msg)
+         |
+         |    @overrides
+         |    def process_table(self, table: Table, port: int) -> Iterator[Optional[TableLike]]:
+         |        if table.empty:
+         |           yield {'html-content': self.render_error("input table is empty.")}
+         |           return
+         |        ${manipulateTable()}
+         |        if table.empty:
+         |           yield {'html-content': self.render_error("input table is empty after removing missing values.")}
+         |           return
+         |        ${createPlotlyFigure()}
+         |        html = plotly.io.to_html(fig, include_plotlyjs='cdn', auto_play=False)
+         |        yield {'html-content': html}
+         |
+         |"""
+    finalcode.encode
+  }
+}