Avoid sending HTML tables in internal Kotlin Notebook <-> Kernel table widget data exchange

Author: koperagen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/DisableRowsLimitWrapper.kt

@@ -5,6 +5,8 @@ import org.jetbrains.kotlinx.dataframe.annotations.RequiredByIntellijPlugin
 
 /**
  * Allows for disabling the rows limit when generating a DISPLAY output in Jupyter.
+ * Used in code that Kotlin Notebook sends to Jupyter Kernel / KotlinNotebookPluginUtils
+ * @param [addHtml] needed to avoid sending HTML in these internal requests, because they won't be displayed anyway, only JSON part of these payloads is used to update "live" state of the widget
  */
 @RequiredByIntellijPlugin
-public data class DisableRowsLimitWrapper(public val value: AnyFrame)
+public data class DisableRowsLimitWrapper(public val value: AnyFrame, public val addHtml: Boolean = true)

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/KotlinNotebookPluginUtils.kt

@@ -63,7 +63,7 @@ public object KotlinNotebookPluginUtils {
      * It's used for example for dynamic pagination in Kotlin Notebook Plugin.
      */
     public fun getRowsSubsetForRendering(df: AnyFrame, startIdx: Int, endIdx: Int): DisableRowsLimitWrapper =
-        DisableRowsLimitWrapper(df[startIdx..<endIdx])
+        DisableRowsLimitWrapper(df[startIdx..<endIdx], addHtml = false)
 
     /**
      * Sorts a dataframe-like object by multiple columns.

dataframe-jupyter/src/main/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/JupyterHtmlRenderer.kt

@@ -38,6 +38,7 @@ internal inline fun <reified T : Any> JupyterHtmlRenderer.render(
     crossinline modifyConfig: T.(DisplayConfiguration) -> DisplayConfiguration = { it },
     applyRowsLimit: Boolean = true,
 ) = builder.renderWithHost<T> { host, value ->
+    val addHtml = (value as? DisableRowsLimitWrapper)?.addHtml ?: true
     val contextRenderer = JupyterCellRenderer(this.notebook, host)
     val reifiedDisplayConfiguration = value.modifyConfig(display)
     val footer = getFooter(value)
@@ -53,20 +54,22 @@ internal inline fun <reified T : Any> JupyterHtmlRenderer.render(
         df.rowsCount()
     }
 
-    val html = DataFrameHtmlData
-        .tableDefinitions(
-            includeJs = reifiedDisplayConfiguration.isolatedOutputs,
-            includeCss = true,
-        ).plus(
-            df.toHtml(
-                // is added later to make sure it's put outside of potential iFrames
-                configuration = reifiedDisplayConfiguration.copy(enableFallbackStaticTables = false),
-                cellRenderer = contextRenderer,
-            ) { footer },
-        ).toJupyterHtmlData()
+    val html by lazy {
+        DataFrameHtmlData
+            .tableDefinitions(
+                includeJs = reifiedDisplayConfiguration.isolatedOutputs,
+                includeCss = true,
+            ).plus(
+                df.toHtml(
+                    // is added later to make sure it's put outside of potential iFrames
+                    configuration = reifiedDisplayConfiguration.copy(enableFallbackStaticTables = false),
+                    cellRenderer = contextRenderer,
+                ) { footer },
+            ).toJupyterHtmlData()
+    }
 
     // Generates a static version of the table which can be displayed in GitHub previews etc.
-    val staticHtml = df.toStaticHtml(reifiedDisplayConfiguration, DefaultCellRenderer).toJupyterHtmlData()
+    val staticHtml by lazy { df.toStaticHtml(reifiedDisplayConfiguration, DefaultCellRenderer).toJupyterHtmlData() }
 
     if (notebook.kernelVersion >= KotlinKernelVersion.from(MIN_KERNEL_VERSION_FOR_NEW_TABLES_UI)!!) {
         val ideBuildNumber = KotlinNotebookPluginUtils.getKotlinNotebookIDEBuildNumber()
@@ -94,8 +97,13 @@ internal inline fun <reified T : Any> JupyterHtmlRenderer.render(
                 )
             }
         }
-
-        notebook.renderAsIFrameAsNeeded(data = html, staticData = staticHtml, jsonEncodedDf = jsonEncodedDf)
+        if (!addHtml) {
+            mimeResult(
+                "application/kotlindataframe+json" to jsonEncodedDf,
+            )
+        } else {
+            notebook.renderAsIFrameAsNeeded(data = html, staticData = staticHtml, jsonEncodedDf = jsonEncodedDf)
+        }
     } else {
         notebook.renderHtmlAsIFrameIfNeeded(data = html)
     }