aglinxinyuan · Oct 28, 2026
diff --git a/...src/main/scala/org/apache/texera/amber/operator/visualization/DotPlot/DotPlotOpDesc.scala b/...src/main/scala/org/apache/texera/amber/operator/visualization/DotPlot/DotPlotOpDesc.scala
@@ -21,22 +21,20 @@ package org.apache.texera.amber.operator.visualization.DotPlot
 
 import com.fasterxml.jackson.annotation.{JsonProperty, JsonPropertyDescription}
 import com.kjetland.jackson.jsonSchema.annotations.JsonSchemaTitle
-import org.apache.texera.amber.core.tuple.{AttributeType, Schema}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
 
 import javax.validation.constraints.NotNull
 
-class DotPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class DotPlotOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
 
   @JsonProperty(value = "Count Attribute", required = true)
   @JsonSchemaTitle("Count Attribute")
@@ -45,14 +43,6 @@ class DotPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
   @NotNull(message = "Count Attribute column cannot be empty")
   var countAttribute: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Dot Plot",
@@ -104,10 +94,6 @@ class DotPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
     finalCode.encode
   }
 
-  // Output is an HTML chart, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     val countLit = pyStringLiteral(countAttribute)
     // The error page is written to the same file a plotted chart lands in, so a

diff --git a/.../scala/org/apache/texera/amber/operator/visualization/IcicleChart/IcicleChartOpDesc.scala b/.../scala/org/apache/texera/amber/operator/visualization/IcicleChart/IcicleChartOpDesc.scala
@@ -21,15 +21,13 @@ package org.apache.texera.amber.operator.visualization.IcicleChart
 
 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.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.operator.visualization.hierarchychart.HierarchySection
@@ -47,7 +45,7 @@ import javax.validation.constraints.{NotEmpty, NotNull}
   }
 }
 """)
-class IcicleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class IcicleChartOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
   @JsonProperty(required = true)
   @JsonSchemaTitle("Hierarchy Path")
   @JsonPropertyDescription(
@@ -63,14 +61,6 @@ class IcicleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCo
   @NotNull(message = "Value Column cannot be empty")
   var value: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Icicle Chart",
@@ -136,10 +126,6 @@ class IcicleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCo
     finalCode.encode
   }
 
-  // Output is an HTML chart, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     val attributes = hierarchy.map(section => pyStringLiteral(section.attributeName)).mkString(", ")
     val valueLit = pyStringLiteral(value)

diff --git a/...scala/org/apache/texera/amber/operator/visualization/ImageViz/ImageVisualizerOpDesc.scala b/...scala/org/apache/texera/amber/operator/visualization/ImageViz/ImageVisualizerOpDesc.scala
@@ -28,13 +28,13 @@ import org.apache.texera.amber.pybuilder.PythonTemplateBuilder.{
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
 import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.{PythonOperatorDescriptor, StandaloneCodeGenerator}
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
 
 import javax.validation.constraints.NotNull
-class ImageVisualizerOpDesc extends PythonOperatorDescriptor with StandaloneCodeGenerator {
+class ImageVisualizerOpDesc extends PythonVisualizationOpDesc {
 
   @JsonProperty(required = true)
   @JsonSchemaTitle("image content column")
@@ -43,14 +43,6 @@ class ImageVisualizerOpDesc extends PythonOperatorDescriptor with StandaloneCode
   @NotNull(message = "image content column cannot be empty")
   var binaryContent: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Image Visualizer",
@@ -101,10 +93,6 @@ class ImageVisualizerOpDesc extends PythonOperatorDescriptor with StandaloneCode
     finalCode.encode
   }
 
-  // Output is an HTML visualization, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = generateStandaloneCode(Map.empty)
 
   /** The executor hands `b64encode` whatever the column holds, so a column of

diff --git a/...main/scala/org/apache/texera/amber/operator/visualization/PythonVisualizationOpDesc.scala b/...main/scala/org/apache/texera/amber/operator/visualization/PythonVisualizationOpDesc.scala
@@ -0,0 +1,42 @@
+/*
+ * 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
+
+import org.apache.texera.amber.core.tuple.{AttributeType, Schema}
+import org.apache.texera.amber.core.workflow.PortIdentity
+import org.apache.texera.amber.operator.{PythonOperatorDescriptor, StandaloneCodeGenerator}
+
+/**
+  * A chart drawn by Python code.
+  *
+  * Its one output port carries a single `html-content` STRING column, whatever
+  * the input schemas are: that column is where the frontend finds the rendered
+  * chart. Its exported script writes the chart to a file rather than producing
+  * a table, so the translator does not print it as a leaf DataFrame.
+  */
+trait PythonVisualizationOpDesc extends PythonOperatorDescriptor with StandaloneCodeGenerator {
+
+  override def getOutputSchemas(
+      inputSchemas: Map[PortIdentity, Schema]
+  ): Map[PortIdentity, Schema] =
+    Map(operatorInfo.outputPorts.head.id -> Schema().add("html-content", AttributeType.STRING))
+
+  override def producesDataFrame(): Boolean = false
+}
diff --git a/...che/texera/amber/operator/visualization/ScatterMatrixChart/ScatterMatrixChartOpDesc.scala b/...che/texera/amber/operator/visualization/ScatterMatrixChart/ScatterMatrixChartOpDesc.scala
@@ -21,15 +21,13 @@ package org.apache.texera.amber.operator.visualization.ScatterMatrixChart
 
 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.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.{
   AutofillAttributeName,
   AutofillAttributeNameList
@@ -50,7 +48,7 @@ import javax.validation.constraints.{NotEmpty, NotNull}
   }
 }
 """)
-class ScatterMatrixChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class ScatterMatrixChartOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
 
   @JsonProperty(value = "Selected Attributes", required = true)
   @JsonSchemaTitle("Selected Attributes")
@@ -66,14 +64,6 @@ class ScatterMatrixChartOpDesc extends PythonOperatorDescriptor with PlotlyStand
   @NotNull(message = "Color Column cannot be empty")
   var color: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Scatter Matrix Chart",
@@ -118,10 +108,6 @@ class ScatterMatrixChartOpDesc extends PythonOperatorDescriptor with PlotlyStand
     finalcode.encode
   }
 
-  // Output is an HTML visualization, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     val dimensions = selectedAttributes.map(pyStringLiteral).mkString(", ")
     // No empty-input guard, matching generatePythonCode: it goes straight to

diff --git a/...c/main/scala/org/apache/texera/amber/operator/visualization/barChart/BarChartOpDesc.scala b/...c/main/scala/org/apache/texera/amber/operator/visualization/barChart/BarChartOpDesc.scala
@@ -21,15 +21,13 @@ package org.apache.texera.amber.operator.visualization.barChart
 
 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.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
@@ -46,7 +44,7 @@ import javax.validation.constraints.NotNull
   }
 }
 """)
-class BarChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class BarChartOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
 
   @JsonProperty(value = "value", required = true)
   @JsonSchemaTitle("Value Column")
@@ -79,14 +77,6 @@ class BarChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode
   @AutofillAttributeName
   var pattern: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Bar Chart",
@@ -159,10 +149,6 @@ class BarChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode
     finalCode.encode
   }
 
-  // Output is an HTML chart, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     val hasCategory = categoryColumn.nonEmpty && categoryColumn != "No Selection"
     val colorArg = if (hasCategory) pyStringLiteral(categoryColumn) else "None"

diff --git a/...la/org/apache/texera/amber/operator/visualization/boxViolinPlot/BoxViolinPlotOpDesc.scala b/...la/org/apache/texera/amber/operator/visualization/boxViolinPlot/BoxViolinPlotOpDesc.scala
@@ -21,15 +21,13 @@ package org.apache.texera.amber.operator.visualization.boxViolinPlot
 
 import com.fasterxml.jackson.annotation.{JsonProperty, JsonPropertyDescription, JsonPropertyOrder}
 import com.kjetland.jackson.jsonSchema.annotations.{JsonSchemaInject, JsonSchemaTitle}
-import org.apache.texera.amber.core.tuple.{AttributeType, Schema}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
@@ -46,7 +44,7 @@ import javax.validation.constraints.NotNull
   }
 }
 """)
-class BoxViolinPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class BoxViolinPlotOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
 
   @JsonProperty(value = "value", required = true)
   @JsonSchemaTitle("Value Column")
@@ -74,14 +72,6 @@ class BoxViolinPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandalone
   )
   var violinPlot: Boolean = _
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Box/Violin Plot",
@@ -156,10 +146,6 @@ class BoxViolinPlotOpDesc extends PythonOperatorDescriptor with PlotlyStandalone
     finalCode.encode
   }
 
-  // Output is a Plotly visualization, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     val horizontal = if (horizontalOrientation) "True" else "False"
     val violin = if (violinPlot) "True" else "False"

diff --git a/.../scala/org/apache/texera/amber/operator/visualization/bubbleChart/BubbleChartOpDesc.scala b/.../scala/org/apache/texera/amber/operator/visualization/bubbleChart/BubbleChartOpDesc.scala
@@ -21,15 +21,13 @@ package org.apache.texera.amber.operator.visualization.bubbleChart
 
 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.pybuilder.PythonTemplateBuilder.{
   PythonTemplateBuilderStringContext,
   pyStringLiteral
 }
 import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
-import org.apache.texera.amber.core.workflow.PortIdentity
-import org.apache.texera.amber.operator.PythonOperatorDescriptor
 import org.apache.texera.amber.operator.visualization.PlotlyStandaloneCode
+import org.apache.texera.amber.operator.visualization.PythonVisualizationOpDesc
 import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
 import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
 import org.apache.texera.amber.pybuilder.PythonTemplateBuilder
@@ -53,7 +51,7 @@ import javax.validation.constraints.NotNull
   }
 }
 """)
-class BubbleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCode {
+class BubbleChartOpDesc extends PythonVisualizationOpDesc with PlotlyStandaloneCode {
 
   @JsonProperty(value = "xValue", required = true)
   @JsonSchemaTitle("X-Column")
@@ -90,14 +88,6 @@ class BubbleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCo
   @AutofillAttributeName
   var colorCategory: EncodableString = ""
 
-  override def getOutputSchemas(
-      inputSchemas: Map[PortIdentity, Schema]
-  ): Map[PortIdentity, Schema] = {
-    val outputSchema = Schema()
-      .add("html-content", AttributeType.STRING)
-    Map(operatorInfo.outputPorts.head.id -> outputSchema)
-  }
-
   override def operatorInfo: OperatorInfo =
     OperatorInfo.forVisualization(
       "Bubble Chart",
@@ -162,10 +152,6 @@ class BubbleChartOpDesc extends PythonOperatorDescriptor with PlotlyStandaloneCo
     finalCode.encode
   }
 
-  // Output is an HTML chart, not a tabular DataFrame.
-  // The translator skips it in the leaf-DataFrame print block.
-  override def producesDataFrame(): Boolean = false
-
   override def generateStandaloneCode(): String = {
     // Same rule as the platform path: an unset column is "no color" even with the
     // toggle on, else px.scatter(color='') fails.