From c16dcefe716fb0c76ca4d7bd72aa5ed4243ad7d4 Mon Sep 17 00:00:00 2001 From: "4111978+Fred-Wu@users.noreply.github.com" <4111978+Fred-Wu@users.noreply.github.com> Date: Sun, 20 Sep 2026 16:38:54 +1000 Subject: [PATCH 1/6] Enable viewing nested workspace lists and tables --- package.json | 2 +- sess/R/handlers.R | 13 ++++++++++++- sess/R/server.R | 1 + sess/inst/tinytest/test-dataview.R | 9 +++++++++ src/extension.ts | 2 +- src/workspaceViewer.ts | 19 +++++++++++++++---- 6 files changed, 39 insertions(+), 7 deletions(-) diff --git a/package.json b/package.json index f9b1a747..fb774494 100644 --- a/package.json +++ b/package.json @@ -1119,7 +1119,7 @@ { "command": "r.workspaceViewer.view", "group": "inline", - "when": "view == workspaceViewer && viewItem == rootNode" + "when": "view == workspaceViewer && (viewItem == rootNode || viewItem == viewableNode)" }, { "command": "r.workspaceViewer.remove", diff --git a/sess/R/handlers.R b/sess/R/handlers.R index 6dec46e2..2cd74ea9 100644 --- a/sess/R/handlers.R +++ b/sess/R/handlers.R @@ -118,6 +118,7 @@ workspace_child_item <- function(object, str, selector) { class = paste(class(object), collapse = ", "), type = typeof(object), has_children = workspace_child_count(object) > 0L, + viewable = is.list(object) || dataview_is_table(object), selector = selector ) } @@ -130,6 +131,16 @@ workspace_child_label <- function(name, index) { } } +handle_workspace_view <- function(name, path = list()) { + title <- paste0(c(name, vapply(path, function(selector) switch(selector$kind, + index = if (!is.null(selector$name) && !is.na(selector$name) && nzchar(selector$name)) paste0("$", selector$name) else paste0("[[", selector$value, "]]"), + name = paste0("$", selector$value), + slot = paste0("@", selector$value) + ), "")), collapse = "") + utils::View(workspace_object(name, path), title = title) + TRUE +} + get_workspace_children <- function(name, path = list(), start = 1L) { tryCatch({ object <- workspace_object(name, path) @@ -186,7 +197,7 @@ get_workspace_children <- function(name, path = list(), start = 1L) { ": ", trimws(try_capture_str(child)) ), - list(kind = "index", value = index) + list(kind = "index", value = index, name = child_name) ) }) } diff --git a/sess/R/server.R b/sess/R/server.R index fe5c8eba..adc90132 100644 --- a/sess/R/server.R +++ b/sess/R/server.R @@ -175,6 +175,7 @@ dispatch_message <- function(line) { handlers <- list( "workspace" = function(p) get_workspace_data(), "workspace_children" = function(p) get_workspace_children(p$name, p$path, p$start), + "workspace_view" = function(p) handle_workspace_view(p$name, p$path), "hover" = function(p) handle_hover(p$expr), "completion" = function(p) handle_complete(p$expr, p$trigger), "plot_latest" = function(p) handle_plot_latest(p), diff --git a/sess/inst/tinytest/test-dataview.R b/sess/inst/tinytest/test-dataview.R index 82e7fe2d..bda38e66 100644 --- a/sess/inst/tinytest/test-dataview.R +++ b/sess/inst/tinytest/test-dataview.R @@ -79,3 +79,12 @@ local({ ), 2L, info = case_name) } }) + + +# Workspace children expose the View action only for supported table objects. +local({ + selector <- list(kind = "index", value = 1L) + expect_true(sess:::workspace_child_item(data.frame(x = 1), "df", selector)$viewable) + expect_true(sess:::workspace_child_item(matrix(1:4, 2), "matrix", selector)$viewable) + expect_true(sess:::workspace_child_item(list(x = 1), "list", selector)$viewable) +}) diff --git a/src/extension.ts b/src/extension.ts index 68cc595d..9fc9cfc9 100644 --- a/src/extension.ts +++ b/src/extension.ts @@ -138,7 +138,7 @@ export async function activate(context: vscode.ExtensionContext): Promise rWorkspace?.refresh(), - 'r.workspaceViewer.view': (node: workspaceViewer.GlobalEnvItem) => node?.label && workspaceViewer.viewItem(node.label), + 'r.workspaceViewer.view': (node: workspaceViewer.GlobalEnvItem) => node && workspaceViewer.viewItem(node), 'r.workspaceViewer.remove': (node: workspaceViewer.GlobalEnvItem) => node?.label && workspaceViewer.removeItem(node.label), 'r.workspaceViewer.clear': workspaceViewer.clearWorkspace, 'r.workspaceViewer.load': workspaceViewer.loadWorkspace, diff --git a/src/workspaceViewer.ts b/src/workspaceViewer.ts index 14162fb4..ad831a2f 100644 --- a/src/workspaceViewer.ts +++ b/src/workspaceViewer.ts @@ -21,6 +21,7 @@ interface WorkspaceChild { class: string; type: string; has_children: boolean; + viewable?: boolean; selector?: WorkspaceSelector; } @@ -149,7 +150,8 @@ export class WorkspaceDataProvider implements TreeDataProvider { undefined, child.has_children, element.rootName, - child.selector ? [...element.objectPath, child.selector] : element.objectPath + child.selector ? [...element.objectPath, child.selector] : element.objectPath, + child.viewable ) ); if (page.nextStart !== undefined) { @@ -351,6 +353,7 @@ export class GlobalEnvItem extends TreeItem { hasChildren?: boolean, rootName?: string, objectPath?: WorkspaceSelector[], + viewable?: boolean, ) { super( label, @@ -369,7 +372,7 @@ export class GlobalEnvItem extends TreeItem { ); this.tooltip = this.getTooltip(label, rClass, treeLevel); this.iconPath = this.getIcon(type, dim); - this.contextValue = treeLevel === 0 ? 'rootNode' : `childNode${this.treeLevel}`; + this.contextValue = treeLevel === 0 ? 'rootNode' : viewable ? 'viewableNode' : `childNode${this.treeLevel}`; } private getDescription(dim: number[] | undefined, str: string, rClass: string, type: string): string { @@ -494,8 +497,16 @@ export function loadWorkspace(): void { }); } -export function viewItem(node: string): void { - void runTextInTerm(`View(${node})`); +export function viewItem(node: GlobalEnvItem): void { + if (globalPipePath && node.rootName) { + void sessionRequest({ + method: 'workspace_view', + params: { + name: node.rootName, + path: node.objectPath, + }, + }); + } } export function removeItem(node: string): void { From bcf1db8a4af35fa99f7706eb72cd1f99109ad56e Mon Sep 17 00:00:00 2001 From: "4111978+Fred-Wu@users.noreply.github.com" <4111978+Fred-Wu@users.noreply.github.com> Date: Sun, 20 Sep 2026 16:39:00 +1000 Subject: [PATCH 2/6] Show shallow list summaries with child navigation --- sess/R/handlers.R | 18 +++++++ sess/R/hooks.R | 21 +++++++- sess/R/server.R | 1 + src/session.ts | 124 +++++++++++++++++++++++++++++----------------- 4 files changed, 116 insertions(+), 48 deletions(-) diff --git a/sess/R/handlers.R b/sess/R/handlers.R index 2cd74ea9..c54c19d2 100644 --- a/sess/R/handlers.R +++ b/sess/R/handlers.R @@ -209,6 +209,24 @@ get_workspace_children <- function(name, path = list(), start = 1L) { }, error = function(e) list(children = I(list()), next_start = NULL)) } +handle_listview_view <- function(view_id, index) { + state <- .sess_env$dataviews[[as.character(view_id)]] + index <- as.integer(index) + if (is.null(state) || !identical(state$type, "list") || + is.na(index) || index < 1L || index > length(state$data)) { + return(FALSE) + } + child_names <- names(state$data) + child_name <- if (is.null(child_names)) NULL else child_names[[index]] + title <- if (!is.null(child_name) && !is.na(child_name) && nzchar(child_name)) { + paste0(state$title, "$", child_name) + } else { + paste0(state$title, "[[", index, "]]") + } + utils::View(state$data[[index]], title = title) + TRUE +} + handle_hover <- function(expr_str) { tryCatch( { diff --git a/sess/R/hooks.R b/sess/R/hooks.R index 0cb2dd90..c029fb77 100644 --- a/sess/R/hooks.R +++ b/sess/R/hooks.R @@ -38,13 +38,30 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F view_id = registration$view_id )) } else if (is.list(x)) { + view_id <- dataview_new_id() + .sess_env$dataviews[[view_id]] <- list( + type = "list", + data = x, + title = paste(as.character(title), collapse = "\n") + ) + x_names <- names(x) + children <- lapply(seq_along(x), function(index) { + child <- x[[index]] + list( + label = workspace_child_label(if (is.null(x_names)) NULL else x_names[[index]], index), + str = trimws(try_capture_str(child)), + viewable = is.list(child) || dataview_is_table(child), + index = index + ) + }) file_path <- tempfile(tmpdir = .sess_env$tempdir, fileext = ".json") - jsonlite::write_json(x, file_path, auto_unbox = TRUE, null = "null", na = "string") + jsonlite::write_json(list(children = I(children)), file_path, auto_unbox = TRUE) notify_client("dataview", list( title = title, file = file_path, source = "list", - type = "json" + type = "json", + view_id = view_id )) } else { code <- if (is.primitive(x)) utils::capture.output(print(x)) else deparse(x) diff --git a/sess/R/server.R b/sess/R/server.R index adc90132..475109bf 100644 --- a/sess/R/server.R +++ b/sess/R/server.R @@ -179,6 +179,7 @@ dispatch_message <- function(line) { "hover" = function(p) handle_hover(p$expr), "completion" = function(p) handle_complete(p$expr, p$trigger), "plot_latest" = function(p) handle_plot_latest(p), + "listview_view" = function(p) handle_listview_view(p$view_id, p$index), "dataview_init" = function(p) handle_dataview_init(p), "dataview_page" = function(p) handle_dataview_page(p), "dataview_dispose" = function(p) handle_dataview_dispose(p) diff --git a/src/session.ts b/src/session.ts index 9fd9125f..0e3bfa1a 100644 --- a/src/session.ts +++ b/src/session.ts @@ -745,6 +745,22 @@ export async function showDataView(source: string, type: string, title: string, }); const content = await getListHtml(panel.webview, file, title); panel.iconPath = new UriIcon('open-preview'); + if (viewId) { + panel.webview.onDidReceiveMessage((message: { message?: string; index?: number }) => { + if (message.message === 'listview/view' && typeof message.index === 'number' && Number.isInteger(message.index)) { + void sessionRequest({ + method: 'listview_view', + params: { view_id: viewId, index: message.index }, + }); + } + }); + panel.onDidDispose(() => { + void sessionRequest({ + method: 'dataview_dispose', + params: { view_id: viewId }, + }); + }); + } panel.webview.html = content; } else { await commands.executeCommand('vscode.open', Uri.file(file), { @@ -1552,7 +1568,7 @@ export async function getTableHtml(webview: Webview, file: string | undefined, t } export async function getListHtml(webview: Webview, file: string, title: string): Promise { - const content = await readContent(file, 'utf8'); + const content = (await readContent(file, 'utf8')).replace(/ @@ -1561,64 +1577,80 @@ export async function getListHtml(webview: Webview, file: string, title: string) ${escapeHtml(title)} - - - - - - 

+    

+    
 
 
 `;

From 051ace3d48436609d3f656642805da91528447d6 Mon Sep 17 00:00:00 2001
From: "4111978+Fred-Wu@users.noreply.github.com"
 <4111978+Fred-Wu@users.noreply.github.com>
Date: Sun, 20 Sep 2026 16:39:07 +1000
Subject: [PATCH 3/6] Match list viewer actions to workspace View icons

---
 images/icons/dark/open-preview-codicon.svg  |  1 +
 images/icons/light/open-preview-codicon.svg |  1 +
 src/session.ts                              | 32 +++++++++++++++++----
 3 files changed, 28 insertions(+), 6 deletions(-)
 create mode 100644 images/icons/dark/open-preview-codicon.svg
 create mode 100644 images/icons/light/open-preview-codicon.svg

diff --git a/images/icons/dark/open-preview-codicon.svg b/images/icons/dark/open-preview-codicon.svg
new file mode 100644
index 00000000..5dc0bba6
--- /dev/null
+++ b/images/icons/dark/open-preview-codicon.svg
@@ -0,0 +1 @@
+
diff --git a/images/icons/light/open-preview-codicon.svg b/images/icons/light/open-preview-codicon.svg
new file mode 100644
index 00000000..9e363217
--- /dev/null
+++ b/images/icons/light/open-preview-codicon.svg
@@ -0,0 +1 @@
+
diff --git a/src/session.ts b/src/session.ts
index 0e3bfa1a..057711e8 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -741,7 +741,7 @@ export async function showDataView(source: string, type: string, title: string,
                 enableScripts: true,
                 enableFindWidget: true,
                 retainContextWhenHidden: true,
-                localResourceRoots: [Uri.file(resDir)],
+                localResourceRoots: [Uri.file(resDir), Uri.file(extensionContext.asAbsolutePath('images/icons'))],
             });
         const content = await getListHtml(panel.webview, file, title);
         panel.iconPath = new UriIcon('open-preview');
@@ -1569,6 +1569,9 @@ export async function getTableHtml(webview: Webview, file: string | undefined, t
 
 export async function getListHtml(webview: Webview, file: string, title: string): Promise {
     const content = (await readContent(file, 'utf8')).replace(/
@@ -1607,14 +1610,29 @@ export async function getListHtml(webview: Webview, file: string, title: string)
         white-space: pre-wrap;
     }
     button {
+        display: flex;
+        align-items: center;
         border: 0;
-        padding: 2px 8px;
-        color: var(--vscode-button-foreground);
-        background-color: var(--vscode-button-background);
+        padding: 2px;
+        color: var(--vscode-foreground);
+        background: transparent;
         cursor: pointer;
     }
     button:hover {
-        background-color: var(--vscode-button-hoverBackground);
+        background-color: var(--vscode-toolbar-hoverBackground);
+    }
+    button img {
+        width: 16px;
+        height: 16px;
+    }
+    .light-icon {
+        display: none;
+    }
+    body.vscode-light .dark-icon {
+        display: none;
+    }
+    body.vscode-light .light-icon {
+        display: block;
     }
     
 
@@ -1641,7 +1659,9 @@ export async function getListHtml(webview: Webview, file: string, title: string)
 
         if (item.viewable) {
             const button = document.createElement('button');
-            button.textContent = 'View';
+            button.title = 'View';
+            button.setAttribute('aria-label', 'View');
+            button.innerHTML = '';
             button.addEventListener('click', () => {
                 vscode.postMessage({ message: 'listview/view', index: item.index });
             });

From 34ee660af987351e4958c3093790f483b21574d2 Mon Sep 17 00:00:00 2001
From: "4111978+Fred-Wu@users.noreply.github.com"
 <4111978+Fred-Wu@users.noreply.github.com>
Date: Sun, 20 Sep 2026 16:39:13 +1000
Subject: [PATCH 4/6] Reuse list viewer panels by title

---
 sess/R/hooks.R | 20 +++++++++++---------
 src/session.ts | 25 +++++++++++++++++++------
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/sess/R/hooks.R b/sess/R/hooks.R
index c029fb77..747e33f0 100644
--- a/sess/R/hooks.R
+++ b/sess/R/hooks.R
@@ -14,21 +14,24 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F
     # make sure title is computed.
     force(title)
 
-    if (dataview_is_table(x)) {
+    view_type <- if (dataview_is_table(x)) "table" else if (is.list(x)) "list" else "object"
+    if (view_type != "object") {
       title_key <- paste(as.character(title), collapse = "\n")
+      registry_key <- paste0(view_type, ":", title_key)
       dataview_registry <- .sess_env$dataview_registry
-      has_view_id <- nzchar(title_key) &&
-        exists(title_key, envir = dataview_registry, inherits = FALSE)
-      view_id <- if (has_view_id) {
-        get(title_key, envir = dataview_registry, inherits = FALSE)
+      view_id <- if (nzchar(title_key) &&
+                       exists(registry_key, envir = dataview_registry, inherits = FALSE)) {
+        get(registry_key, envir = dataview_registry, inherits = FALSE)
       } else {
         id <- dataview_new_id()
         if (nzchar(title_key)) {
-          assign(title_key, id, envir = dataview_registry)
+          assign(registry_key, id, envir = dataview_registry)
         }
         id
       }
+    }
 
+    if (view_type == "table") {
       registration <- dataview_register(x, view_id = view_id)
 
       notify_client("dataview", list(
@@ -37,12 +40,11 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F
         type = "json",
         view_id = registration$view_id
       ))
-    } else if (is.list(x)) {
-      view_id <- dataview_new_id()
+    } else if (view_type == "list") {
       .sess_env$dataviews[[view_id]] <- list(
         type = "list",
         data = x,
-        title = paste(as.character(title), collapse = "\n")
+        title = title_key
       )
       x_names <- names(x)
       children <- lapply(seq_along(x), function(index) {
diff --git a/src/session.ts b/src/session.ts
index 057711e8..a32f3312 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -732,6 +732,16 @@ export async function showDataView(source: string, type: string, title: string,
         const content = await getTableHtml(panel.webview, file || undefined, title);
         panel.webview.html = content;
     } else if (source === 'list') {
+        if (viewId) {
+            const existing = dynamicDataViewPanels.get(viewId);
+            if (existing) {
+                existing.title = title;
+                existing.reveal(ViewColumn[viewer as keyof typeof ViewColumn], true);
+                existing.webview.html = await getListHtml(existing.webview, file, title);
+                return;
+            }
+        }
+
         const panel = window.createWebviewPanel('dataview', title,
             {
                 preserveFocus: true,
@@ -741,11 +751,11 @@ export async function showDataView(source: string, type: string, title: string,
                 enableScripts: true,
                 enableFindWidget: true,
                 retainContextWhenHidden: true,
-                localResourceRoots: [Uri.file(resDir), Uri.file(extensionContext.asAbsolutePath('images/icons'))],
+                localResourceRoots: [Uri.file(extensionContext.asAbsolutePath('images/icons'))],
             });
-        const content = await getListHtml(panel.webview, file, title);
         panel.iconPath = new UriIcon('open-preview');
         if (viewId) {
+            dynamicDataViewPanels.set(viewId, panel);
             panel.webview.onDidReceiveMessage((message: { message?: string; index?: number }) => {
                 if (message.message === 'listview/view' && typeof message.index === 'number' && Number.isInteger(message.index)) {
                     void sessionRequest({
@@ -755,13 +765,16 @@ export async function showDataView(source: string, type: string, title: string,
                 }
             });
             panel.onDidDispose(() => {
+                if (dynamicDataViewPanels.get(viewId) === panel) {
+                    dynamicDataViewPanels.delete(viewId);
+                }
                 void sessionRequest({
                     method: 'dataview_dispose',
                     params: { view_id: viewId },
                 });
             });
         }
-        panel.webview.html = content;
+        panel.webview.html = await getListHtml(panel.webview, file, title);
     } else {
         await commands.executeCommand('vscode.open', Uri.file(file), {
             preserveFocus: true,
@@ -1568,10 +1581,10 @@ export async function getTableHtml(webview: Webview, file: string | undefined, t
 }
 
 export async function getListHtml(webview: Webview, file: string, title: string): Promise {
-    const content = (await readContent(file, 'utf8')).replace(/

From b2a509b7cd0ddc6b8b7276f003f0cc22d38d8c57 Mon Sep 17 00:00:00 2001
From: "4111978+Fred-Wu@users.noreply.github.com"
 <4111978+Fred-Wu@users.noreply.github.com>
Date: Sun, 20 Sep 2026 20:16:49 +1000
Subject: [PATCH 5/6] Nested View icons now appear for all supported values

---
 sess/R/handlers.R                  | 28 +++++++++++++++-----
 sess/R/hooks.R                     | 41 +++++++++++++++++++++++++-----
 sess/inst/tinytest/test-dataview.R |  9 ++++++-
 3 files changed, 63 insertions(+), 15 deletions(-)

diff --git a/sess/R/handlers.R b/sess/R/handlers.R
index c54c19d2..581bdfec 100644
--- a/sess/R/handlers.R
+++ b/sess/R/handlers.R
@@ -118,7 +118,7 @@ workspace_child_item <- function(object, str, selector) {
     class = paste(class(object), collapse = ", "),
     type = typeof(object),
     has_children = workspace_child_count(object) > 0L,
-    viewable = is.list(object) || dataview_is_table(object),
+    viewable = TRUE,
     selector = selector
   )
 }
@@ -211,19 +211,33 @@ get_workspace_children <- function(name, path = list(), start = 1L) {
 
 handle_listview_view <- function(view_id, index) {
   state <- .sess_env$dataviews[[as.character(view_id)]]
+  if (is.null(state) || !identical(state$type, "list")) {
+    return(FALSE)
+  }
   index <- as.integer(index)
-  if (is.null(state) || !identical(state$type, "list") ||
-      is.na(index) || index < 1L || index > length(state$data)) {
+  child_count <- if (state$kind == "index") length(state$data) else length(state$names)
+  if (length(index) != 1L || is.na(index) || index < 1L || index > child_count) {
     return(FALSE)
   }
-  child_names <- names(state$data)
-  child_name <- if (is.null(child_names)) NULL else child_names[[index]]
-  title <- if (!is.null(child_name) && !is.na(child_name) && nzchar(child_name)) {
+  child_name <- if (is.null(state$names)) NULL else state$names[[index]]
+  if (state$kind == "name" &&
+        (!exists(child_name, envir = state$data, inherits = FALSE) ||
+           bindingIsActive(child_name, state$data))) {
+    return(FALSE)
+  }
+  child <- switch(state$kind,
+    name = get(child_name, envir = state$data, inherits = FALSE),
+    slot = methods::slot(state$data, child_name),
+    index = state$data[[index]]
+  )
+  title <- if (state$kind == "slot") {
+    paste0(state$title, "@", child_name)
+  } else if (!is.null(child_name) && !is.na(child_name) && nzchar(child_name)) {
     paste0(state$title, "$", child_name)
   } else {
     paste0(state$title, "[[", index, "]]")
   }
-  utils::View(state$data[[index]], title = title)
+  utils::View(child, title = title)
   TRUE
 }
 
diff --git a/sess/R/hooks.R b/sess/R/hooks.R
index 747e33f0..077d7074 100644
--- a/sess/R/hooks.R
+++ b/sess/R/hooks.R
@@ -14,7 +14,13 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F
     # make sure title is computed.
     force(title)
 
-    view_type <- if (dataview_is_table(x)) "table" else if (is.list(x)) "list" else "object"
+    view_type <- if (dataview_is_table(x)) {
+      "table"
+    } else if (is.list(x) || is.environment(x) || isS4(x)) {
+      "list"
+    } else {
+      "object"
+    }
     if (view_type != "object") {
       title_key <- paste(as.character(title), collapse = "\n")
       registry_key <- paste0(view_type, ":", title_key)
@@ -41,18 +47,39 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F
         view_id = registration$view_id
       ))
     } else if (view_type == "list") {
+      child_kind <- if (is.environment(x)) "name" else if (isS4(x)) "slot" else "index"
+      x_names <- switch(child_kind,
+        name = workspace_env_names(x),
+        slot = methods::slotNames(x),
+        index = names(x)
+      )
       .sess_env$dataviews[[view_id]] <- list(
         type = "list",
         data = x,
-        title = title_key
+        title = title_key,
+        kind = child_kind,
+        names = x_names
       )
-      x_names <- names(x)
-      children <- lapply(seq_along(x), function(index) {
-        child <- x[[index]]
+      indices <- if (child_kind == "index") seq_along(x) else seq_along(x_names)
+      children <- lapply(indices, function(index) {
+        child_name <- if (is.null(x_names)) NULL else x_names[[index]]
+        label <- if (child_kind == "slot") {
+          paste0("@ ", child_name)
+        } else {
+          workspace_child_label(child_name, index)
+        }
+        if (child_kind == "name" && bindingIsActive(child_name, x)) {
+          return(list(label = label, str = "(active-binding)", viewable = FALSE, index = index))
+        }
+        child <- switch(child_kind,
+          name = get(child_name, envir = x, inherits = FALSE),
+          slot = methods::slot(x, child_name),
+          index = x[[index]]
+        )
         list(
-          label = workspace_child_label(if (is.null(x_names)) NULL else x_names[[index]], index),
+          label = label,
           str = trimws(try_capture_str(child)),
-          viewable = is.list(child) || dataview_is_table(child),
+          viewable = TRUE,
           index = index
         )
       })
diff --git a/sess/inst/tinytest/test-dataview.R b/sess/inst/tinytest/test-dataview.R
index bda38e66..b981a695 100644
--- a/sess/inst/tinytest/test-dataview.R
+++ b/sess/inst/tinytest/test-dataview.R
@@ -81,10 +81,17 @@ local({
 })
 
 
-# Workspace children expose the View action only for supported table objects.
+# Workspace children expose View for both structured and text-viewable objects.
 local({
   selector <- list(kind = "index", value = 1L)
   expect_true(sess:::workspace_child_item(data.frame(x = 1), "df", selector)$viewable)
   expect_true(sess:::workspace_child_item(matrix(1:4, 2), "matrix", selector)$viewable)
   expect_true(sess:::workspace_child_item(list(x = 1), "list", selector)$viewable)
+  expect_true(sess:::workspace_child_item(new.env(), "environment", selector)$viewable)
+  expect_true(sess:::workspace_child_item(pairlist(x = 1), "pairlist", selector)$viewable)
+  methods::setClass("list_viewer_test_slots", slots = c(child = "list"))
+  on.exit(methods::removeClass("list_viewer_test_slots"), add = TRUE)
+  object <- methods::new("list_viewer_test_slots", child = list(x = 1))
+  expect_true(sess:::workspace_child_item(object, "S4", selector)$viewable)
+  expect_true(sess:::workspace_child_item(1:3, "vector", selector)$viewable)
 })

From 856dbea7073844baecfc3096761dec2780d5e179 Mon Sep 17 00:00:00 2001
From: "4111978+Fred-Wu@users.noreply.github.com"
 <4111978+Fred-Wu@users.noreply.github.com>
Date: Sun, 20 Sep 2026 21:49:25 +1000
Subject: [PATCH 6/6] Load list viewer items on demand using workspace
 pagination

---
 sess/R/handlers.R                  | 116 +++++++++++++++--------------
 sess/R/hooks.R                     |  26 -------
 sess/R/server.R                    |   2 +-
 sess/inst/tinytest/test-dataview.R |  31 ++++++++
 src/session.ts                     | 113 ++++++++++++++++++++--------
 5 files changed, 174 insertions(+), 114 deletions(-)

diff --git a/sess/R/handlers.R b/sess/R/handlers.R
index 581bdfec..b5538bb9 100644
--- a/sess/R/handlers.R
+++ b/sess/R/handlers.R
@@ -141,72 +141,76 @@ handle_workspace_view <- function(name, path = list()) {
   TRUE
 }
 
-get_workspace_children <- function(name, path = list(), start = 1L) {
+get_workspace_children <- function(name = NULL, path = list(), start = 1L, view_id = NULL) {
   tryCatch({
-    object <- workspace_object(name, path)
-    child_count <- workspace_child_count(object)
-    if (child_count == 0L) {
-      return(list(children = I(list()), next_start = NULL))
+    if (is.null(view_id)) {
+      object <- workspace_object(name, path)
+      kind <- if (is.environment(object)) "name" else if (isS4(object)) "slot" else "index"
+      child_names <- switch(kind,
+        name = workspace_env_names(object),
+        slot = methods::slotNames(object),
+        index = names(object)
+      )
+    } else {
+      state <- dataview_get_state(view_id)
+      if (!identical(state$type, "list")) stop("Not a list view")
+      object <- state$data
+      kind <- state$kind
+      child_names <- state$names
     }
-
+    child_count <- if (kind == "index") workspace_child_count(object) else length(child_names)
     start <- max(1L, as.integer(start))
     end <- min(child_count, start + workspace_child_page_size - 1L)
     if (start > end) {
       return(list(children = I(list()), next_start = NULL))
     }
 
-    children <- if (is.environment(object)) {
-      child_names <- workspace_env_names(object)[seq.int(start, end)]
-      lapply(child_names, function(child_name) {
-        if (bindingIsActive(child_name, object)) {
-          list(
-            str = paste0("$ ", child_name, ": (active-binding)"),
-            class = "active_binding",
-            type = "active_binding",
-            has_children = FALSE
-          )
+    children <- lapply(seq.int(start, end), function(index) {
+      child_name <- if (is.null(child_names)) NULL else child_names[[index]]
+      label <- if (kind == "slot") {
+        paste0("@ ", child_name)
+      } else {
+        workspace_child_label(child_name, index)
+      }
+      unavailable <- if (kind == "name" && !exists(child_name, envir = object, inherits = FALSE)) {
+        "removed"
+      } else if (kind == "name" && bindingIsActive(child_name, object)) {
+        "active_binding"
+      } else {
+        NULL
+      }
+      if (!is.null(unavailable)) {
+        summary <- if (unavailable == "removed") "(removed)" else "(active-binding)"
+        if (!is.null(view_id)) {
+          return(list(label = label, str = summary, viewable = FALSE, index = index))
+        }
+        return(list(
+          str = paste0(label, ": ", summary), class = unavailable,
+          type = unavailable, has_children = FALSE
+        ))
+      }
+      child <- switch(kind,
+        name = get(child_name, envir = object, inherits = FALSE),
+        slot = methods::slot(object, child_name),
+        index = object[[index]]
+      )
+      summary <- trimws(try_capture_str(child))
+      if (!is.null(view_id)) {
+        list(label = label, str = summary, viewable = TRUE, index = index)
+      } else {
+        selector <- if (kind == "index") {
+          list(kind = kind, value = index, name = child_name)
         } else {
-          child <- get(child_name, envir = object, inherits = FALSE)
-          workspace_child_item(
-            child,
-            paste0("$ ", child_name, ": ", trimws(try_capture_str(child))),
-            list(kind = "name", value = child_name)
-          )
+          list(kind = kind, value = child_name)
         }
-      })
-    } else if (isS4(object)) {
-      child_names <- methods::slotNames(object)[seq.int(start, end)]
-      lapply(child_names, function(child_name) {
-        child <- methods::slot(object, child_name)
-        workspace_child_item(
-          child,
-          paste0("@ ", child_name, ": ", trimws(try_capture_str(child))),
-          list(kind = "slot", value = child_name)
-        )
-      })
-    } else {
-      indices <- seq.int(start, end)
-      child_names <- names(object)
-      lapply(indices, function(index) {
-        child <- object[[index]]
-        child_name <- if (is.null(child_names)) NULL else child_names[[index]]
-        workspace_child_item(
-          child,
-          paste0(
-            workspace_child_label(child_name, index),
-            ": ",
-            trimws(try_capture_str(child))
-          ),
-          list(kind = "index", value = index, name = child_name)
-        )
-      })
-    }
-
-    list(
-      children = I(children),
-      next_start = if (end < child_count) end + 1L else NULL
-    )
-  }, error = function(e) list(children = I(list()), next_start = NULL))
+        workspace_child_item(child, paste0(label, ": ", summary), selector)
+      }
+    })
+    list(children = I(children), next_start = if (end < child_count) end + 1L else NULL)
+  }, error = function(e) {
+    if (!is.null(view_id)) stop(e)
+    list(children = I(list()), next_start = NULL)
+  })
 }
 
 handle_listview_view <- function(view_id, index) {
diff --git a/sess/R/hooks.R b/sess/R/hooks.R
index 077d7074..be00ef02 100644
--- a/sess/R/hooks.R
+++ b/sess/R/hooks.R
@@ -60,34 +60,8 @@ register_hooks <- function(use_rstudioapi = TRUE, use_httpgd = TRUE, use_jgd = F
         kind = child_kind,
         names = x_names
       )
-      indices <- if (child_kind == "index") seq_along(x) else seq_along(x_names)
-      children <- lapply(indices, function(index) {
-        child_name <- if (is.null(x_names)) NULL else x_names[[index]]
-        label <- if (child_kind == "slot") {
-          paste0("@ ", child_name)
-        } else {
-          workspace_child_label(child_name, index)
-        }
-        if (child_kind == "name" && bindingIsActive(child_name, x)) {
-          return(list(label = label, str = "(active-binding)", viewable = FALSE, index = index))
-        }
-        child <- switch(child_kind,
-          name = get(child_name, envir = x, inherits = FALSE),
-          slot = methods::slot(x, child_name),
-          index = x[[index]]
-        )
-        list(
-          label = label,
-          str = trimws(try_capture_str(child)),
-          viewable = TRUE,
-          index = index
-        )
-      })
-      file_path <- tempfile(tmpdir = .sess_env$tempdir, fileext = ".json")
-      jsonlite::write_json(list(children = I(children)), file_path, auto_unbox = TRUE)
       notify_client("dataview", list(
         title = title,
-        file = file_path,
         source = "list",
         type = "json",
         view_id = view_id
diff --git a/sess/R/server.R b/sess/R/server.R
index 475109bf..8b0d1023 100644
--- a/sess/R/server.R
+++ b/sess/R/server.R
@@ -174,7 +174,7 @@ dispatch_message <- function(line) {
     # Request from vscode → R must reply
     handlers <- list(
       "workspace" = function(p) get_workspace_data(),
-      "workspace_children" = function(p) get_workspace_children(p$name, p$path, p$start),
+      "workspace_children" = function(p) get_workspace_children(p$name, p$path, p$start, p$view_id),
       "workspace_view" = function(p) handle_workspace_view(p$name, p$path),
       "hover" = function(p) handle_hover(p$expr),
       "completion" = function(p) handle_complete(p$expr, p$trigger),
diff --git a/sess/inst/tinytest/test-dataview.R b/sess/inst/tinytest/test-dataview.R
index b981a695..ec5dc142 100644
--- a/sess/inst/tinytest/test-dataview.R
+++ b/sess/inst/tinytest/test-dataview.R
@@ -95,3 +95,34 @@ local({
   expect_true(sess:::workspace_child_item(object, "S4", selector)$viewable)
   expect_true(sess:::workspace_child_item(1:3, "vector", selector)$viewable)
 })
+
+# List pages inspect only the requested children, with stable indices across pages.
+local({
+  runtime <- sess:::.sess_env
+  previous <- runtime$dataviews
+  on.exit(runtime$dataviews <- previous, add = TRUE)
+  object <- new.env(parent = emptyenv())
+  child_names <- paste0("item", seq_len(501L))
+  for (name in child_names[1:500]) assign(name, 1L, envir = object)
+  delayedAssign("item501", stop("unrequested binding was evaluated"), assign.env = object)
+  runtime$dataviews$paging_test <- list(
+    type = "list", data = object, kind = "name", names = child_names, title = "object"
+  )
+
+  first <- sess:::get_workspace_children(view_id = "paging_test", start = 1L)
+  expect_length(first$children, 500L)
+  expect_equal(first$next_start, 501L)
+  expect_equal(vapply(first$children, `[[`, 1L, "index"), 1:500)
+
+  # Removing a binding must not shift later indices or fail the next page.
+  rm("item501", envir = object)
+  last <- sess:::get_workspace_children(view_id = "paging_test", start = 501L)
+  expect_equal(last$children[[1L]]$label, "$ item501")
+  expect_false(last$children[[1L]]$viewable)
+  expect_null(last$next_start)
+  makeActiveBinding("item501", function() stop("active binding was evaluated"), object)
+  last <- sess:::get_workspace_children(view_id = "paging_test", start = 501L)
+  expect_equal(last$children[[1L]]$str, "(active-binding)")
+  expect_false(last$children[[1L]]$viewable)
+  expect_length(sess:::get_workspace_children(view_id = "paging_test", start = 502L)$children, 0L)
+})
diff --git a/src/session.ts b/src/session.ts
index a32f3312..53aeaca3 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -737,7 +737,7 @@ export async function showDataView(source: string, type: string, title: string,
             if (existing) {
                 existing.title = title;
                 existing.reveal(ViewColumn[viewer as keyof typeof ViewColumn], true);
-                existing.webview.html = await getListHtml(existing.webview, file, title);
+                existing.webview.html = getListHtml(existing.webview, title);
                 return;
             }
         }
@@ -756,12 +756,24 @@ export async function showDataView(source: string, type: string, title: string,
         panel.iconPath = new UriIcon('open-preview');
         if (viewId) {
             dynamicDataViewPanels.set(viewId, panel);
-            panel.webview.onDidReceiveMessage((message: { message?: string; index?: number }) => {
+            panel.webview.onDidReceiveMessage(async (message: { message?: string; index?: number; start?: number; requestId?: number }) => {
                 if (message.message === 'listview/view' && typeof message.index === 'number' && Number.isInteger(message.index)) {
                     void sessionRequest({
                         method: 'listview_view',
                         params: { view_id: viewId, index: message.index },
                     });
+                } else if (message.message === 'listview/page' && typeof message.start === 'number' &&
+                    Number.isInteger(message.start) && typeof message.requestId === 'number') {
+                    const page = await sessionRequest({
+                        method: 'workspace_children',
+                        params: { view_id: viewId, start: message.start },
+                    }) as { children?: unknown; next_start?: number | null } | undefined;
+                    void panel.webview.postMessage({
+                        message: 'listview/page',
+                        requestId: message.requestId,
+                        ...page,
+                        error: Array.isArray(page?.children) ? undefined : 'Unable to load items. Check the R session and try again.',
+                    });
                 }
             });
             panel.onDidDispose(() => {
@@ -774,7 +786,7 @@ export async function showDataView(source: string, type: string, title: string,
                 });
             });
         }
-        panel.webview.html = await getListHtml(panel.webview, file, title);
+        panel.webview.html = getListHtml(panel.webview, title);
     } else {
         await commands.executeCommand('vscode.open', Uri.file(file), {
             preserveFocus: true,
@@ -1580,8 +1592,7 @@ export async function getTableHtml(webview: Webview, file: string | undefined, t
 `;
 }
 
-export async function getListHtml(webview: Webview, file: string, title: string): Promise {
-    const content = (await fs.readFile(file, 'utf8')).replace(/
 
     

+    
+