Merge pull request #455 from plotly/copilot/provide-dynamic-columns-detail-grid

BSd3v · web-flow · commit 861197873d94 · 2026-06-25T08:15:02.000-04:00
Add dynamic `detailCellRendererParams` support for Master/Detail detail-grid columns
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,7 @@ Links "DE#nnn" prior to version 2.0 point to the Dash Enterprise closed-source D
 
 ### Added
 - [#453](https://github.com/plotly/dash-ag-grid/pull/453) Test for changelog entry
+- [#455](https://github.com/plotly/dash-ag-grid/pull/455) Added support for dynamic `detailCellRendererParams` in Master/Detail, including dynamic detail-grid column definitions.
 
 ### Changed
 - [#452](https://github.com/plotly/dash-ag-grid/pull/452) 
diff --git a/docs/examples/enterprise/master_detail.py b/docs/examples/enterprise/master_detail.py
@@ -26,6 +26,11 @@
     {"headerName": "Pop. (Metro area)", "field": "population_metro"},
 ]
 
+detailColumnDefsSimple = [
+    {"headerName": "City", "field": "city"},
+    {"headerName": "Pop. (City proper)", "field": "population_city"},
+]
+
 rowData = [
     {
         "country": "China",
@@ -164,6 +169,31 @@
             ),
             body=True,
         ),
+        html.Hr(),
+        dbc.Card(
+            dcc.Markdown(
+                "Use a JavaScript function in `detailCellRendererParams` to dynamically define detail columns per expanded row."
+            ),
+            body=True,
+        ),
+        dbc.Card(
+            dag.AgGrid(
+                id="master-detail-table-dynamic-columns",
+                columnDefs=masterColumnDefs,
+                rowData=rowData,
+                columnSize="sizeToFit",
+                enableEnterpriseModules=True,
+                masterDetail=True,
+                detailCellRendererParams={
+                    "function": """params.data.region === "Asia"
+                        ? {detailGridOptions: {columnDefs: %s}, detailColName: "cities", suppressCallback: true}
+                        : {detailGridOptions: {columnDefs: %s}, detailColName: "cities", suppressCallback: true}"""
+                    % (detailColumnDefsSimple, detailColumnDefs)
+                },
+                dashGridOptions={"detailRowAutoHeight": True},
+            ),
+            body=True,
+        ),
     ]
 )
 
diff --git a/src/lib/components/AgGrid.react.js b/src/lib/components/AgGrid.react.js
@@ -600,22 +600,30 @@ DashAgGrid.propTypes = {
      * Specifies the params to be used by the default detail Cell Renderer. See Detail
      * Grids.
      */
-    detailCellRendererParams: PropTypes.shape({
-        /**
-         * Grid options for detail grid in master-detail view.
-         */
-        detailGridOptions: PropTypes.any,
+    detailCellRendererParams: PropTypes.oneOfType([
+        PropTypes.shape({
+            /**
+             * Grid options for detail grid in master-detail view.
+             */
+            detailGridOptions: PropTypes.any,
 
-        /**
-         * Column name where detail grid data is located in main dataset, for master-detail view.
-         */
-        detailColName: PropTypes.string,
+            /**
+             * Column name where detail grid data is located in main dataset, for master-detail view.
+             */
+            detailColName: PropTypes.string,
 
-        /**
-         * Default: true. If true, suppresses the Dash callback in favor of using the data embedded in rowData at the given detailColName.
-         */
-        suppressCallback: PropTypes.bool,
-    }),
+            /**
+             * Default: true. If true, suppresses the Dash callback in favor of using the data embedded in rowData at the given detailColName.
+             */
+            suppressCallback: PropTypes.bool,
+        }),
+        PropTypes.shape({
+            /**
+             * JavaScript function that receives detail row params and returns detailCellRendererParams.
+             */
+            function: PropTypes.string,
+        }),
+    ]),
 
     /**
      * The style to give a particular row. See Row Style.
diff --git a/src/lib/fragments/AgGrid.react.js b/src/lib/fragments/AgGrid.react.js
@@ -588,6 +588,33 @@ export function DashAgGrid(props) {
     const convertOneRef = useRef();
     const convertAllPropsRef = useRef();
 
+    const normalizeDetailCellRendererParams = useCallback(
+        (value) => {
+            if (!value || typeof value !== 'object') {
+                return value;
+            }
+
+            let adjustedVal = value;
+            if ('suppressCallback' in value) {
+                adjustedVal = {
+                    ...adjustedVal,
+                    getDetailRowData: value.suppressCallback
+                        ? suppressGetDetail(value.detailColName)
+                        : callbackGetDetail,
+                };
+            }
+            if ('detailGridOptions' in value) {
+                adjustedVal = assocPath(
+                    ['detailGridOptions', 'components'],
+                    components,
+                    adjustedVal
+                );
+            }
+            return convertAllPropsRef.current(adjustedVal);
+        },
+        [suppressGetDetail, callbackGetDetail, components]
+    );
+
     const convertOne = useCallback(
         (value, target) => {
             if (value) {
@@ -617,29 +644,32 @@ export function DashAgGrid(props) {
                     }, value);
                 }
                 if (GRID_NESTED_FUNCTIONS[target]) {
-                    let adjustedVal = value;
                     if (
                         target === 'rowSelection' &&
                         typeof value === 'string'
                     ) {
                         // to still support rowSelection='single' | 'multiple' deprecated in v32.3.4
                         return value;
                     }
-                    if ('suppressCallback' in value) {
-                        adjustedVal = {
-                            ...adjustedVal,
-                            getDetailRowData: value.suppressCallback
-                                ? suppressGetDetail(value.detailColName)
-                                : callbackGetDetail,
-                        };
-                    }
-                    if ('detailGridOptions' in value) {
-                        adjustedVal = assocPath(
-                            ['detailGridOptions', 'components'],
-                            components,
-                            adjustedVal
-                        );
+                    if (target === 'detailCellRendererParams') {
+                        if (has('function', value)) {
+                            const dynamicDetailParams =
+                                convertMaybeFunction(value);
+                            if (typeof dynamicDetailParams === 'function') {
+                                return (params) =>
+                                    normalizeDetailCellRendererParams(
+                                        dynamicDetailParams(params)
+                                    );
+                            }
+                            return normalizeDetailCellRendererParams(
+                                dynamicDetailParams
+                            );
+                        }
                     }
+                    const adjustedVal =
+                        target === 'detailCellRendererParams'
+                            ? normalizeDetailCellRendererParams(value)
+                            : value;
                     return convertAllPropsRef.current(adjustedVal);
                 }
                 if (GRID_DANGEROUS_FUNCTIONS[target]) {
@@ -675,13 +705,14 @@ export function DashAgGrid(props) {
         [
             convertCol,
             convertMaybeFunctionNoParams,
+            convertMaybeFunction,
+            normalizeDetailCellRendererParams,
             suppressGetDetail,
             callbackGetDetail,
             components,
             convertAllPropsRef.current,
             convertFunction,
             handleDynamicStyle,
-            convertMaybeFunction,
         ]
     );
 
diff --git a/tests/test_recursive_functions.py b/tests/test_recursive_functions.py
@@ -69,7 +69,7 @@ def test_rf001_recursive_functions(dash_duo):
                 {
                     "city": "Shanghai",
                     "population_city": 24870895,
-                    "population_metro": "NA",
+                    "population_metro": 0,
                 },
                 {
                     "city": "Beijing",
@@ -268,6 +268,111 @@ def test_rf001_recursive_functions(dash_duo):
     ).get_attribute("style")
 
 
+def test_rf003_master_detail_dynamic_columns(dash_duo):
+    app = Dash(__name__)
+    masterColumnDefs = [
+        {
+            "headerName": "Country",
+            "field": "country",
+            "cellRenderer": "agGroupCellRenderer",
+        },
+        {"headerName": "Region", "field": "region"},
+    ]
+
+    detailColumnDefsSimple = [
+        {"headerName": "City", "field": "city"},
+        {"headerName": "Pop. (City proper)", "field": "population_city"},
+    ]
+    detailColumnDefs = detailColumnDefsSimple + [
+        {"headerName": "Pop. (Metro area)", "field": "population_metro"},
+    ]
+
+    rowData = [
+        {
+            "country": "China",
+            "region": "Asia",
+            "cities": [
+                {
+                    "city": "Shanghai",
+                    "population_city": 24870895,
+                    "population_metro": 0,
+                },
+            ],
+        },
+        {
+            "country": "United States",
+            "region": "Americas",
+            "cities": [
+                {
+                    "city": "New York",
+                    "population_city": 8398748,
+                    "population_metro": 19303808,
+                },
+            ],
+        },
+    ]
+
+    app.layout = html.Div(
+        [
+            dag.AgGrid(
+                id="grid",
+                columnDefs=masterColumnDefs,
+                rowData=rowData,
+                columnSize="sizeToFit",
+                enableEnterpriseModules=True,
+                masterDetail=True,
+                detailCellRendererParams={
+                    "function": """params.data.region === "Asia"
+                        ? {detailGridOptions: {columnDefs: %s}, detailColName: "cities", suppressCallback: true}
+                        : {detailGridOptions: {columnDefs: %s}, detailColName: "cities", suppressCallback: true}"""
+                    % (detailColumnDefsSimple, detailColumnDefs)
+                },
+                dashGridOptions={"detailRowAutoHeight": True},
+            )
+        ]
+    )
+
+    dash_duo.start_server(app)
+
+    grid = utils.Grid(dash_duo, "grid")
+    grid.wait_for_cell_text(0, 0, "China")
+
+    grid.get_cell_expandable(0, 0).click()
+    until(
+        lambda: [
+            e.text
+            for e in dash_duo.find_elements(
+                '#grid .ag-details-grid [aria-rowindex="1"] .ag-header-cell-text'
+            )
+        ]
+        == ["City", "Pop. (City proper)"],
+        timeout=3,
+    )
+    dash_duo.wait_for_text_to_equal(
+        '#grid .ag-details-grid [row-index="0"] [aria-colindex="2"]', "24870895"
+    )
+
+    grid.get_cell_collapsable(0, 0).click()
+    until(
+        lambda: len(dash_duo.find_elements("#grid .ag-details-grid")) == 0,
+        timeout=3,
+    )
+    grid.get_cell_expandable(1, 0).click()
+    until(
+        lambda: [
+            e.text
+            for e in dash_duo.find_elements(
+                '#grid .ag-details-grid [aria-rowindex="1"] .ag-header-cell-text'
+            )
+        ]
+        == ["City", "Pop. (City proper)", "Pop. (Metro area)"],
+        timeout=3,
+    )
+    dash_duo.wait_for_text_to_equal(
+        '#grid .ag-details-grid [row-index="0"] [aria-colindex="3"]', "19303808"
+    )
+
+
 def test_rf002_recursive_functions_server(dash_duo):
     app = Dash(__name__)
     masterColumnDefs = [
