ag-Grid Master / Detail - Row Selection - ag-grid

Question

Goals
I am trying to add row selection functionality which is connected between the master grid and detail grid.
When a checkbox on a master grid row is selected, I want to select all the checkboxes in the associated detail grid.
When a checkbox on a master grid row is deselected, I want to deselect all the checkboxes in the associated detail grid.
When only partial checkboxes inside of a detail grid are selected, I want the master grid row to show a partial selection icon in the checkbox.
I want to keep count of how many items were selected in all of the detail grids
Questions/Problems
All of this functionality already exists for Groups, but I cannot get it to work for Master/Detail. I've tried adding in the line that I believe should add this for Groups cellRendererParams: {checkbox: true}, but that does nothing for the detail grid.
I've also tried implementing the functionality myself, but I hit a couple of roadblocks.
I don't know how to set the partial-checkbox icon manually or if that's even possible.
I implemented the onSelectionChanged event handler for the detail grid, but inside of the function it looks like I can't access the Angular component context to update the count of selected items. Not sure how to pass in the context this.
Code that I have working so far:
When a checkbox on a master grid is selected/deselected, the checkboxes in the associated detail grid are all selected/deselected.
public onMasterRowSelected() {
this.gridOptions.api.forEachNode(masterRowNode => {
if(masterRowNode.isSelected()) {
this.gridOptions.api.getDetailGridInfo(`detail_${masterRowNode.id}`).api.selectAll();
} else {
this.gridOptions.api.getDetailGridInfo(`detail_${masterRowNode.id}`).api.forEachNode(detailRowNode => detailRowNode.setSelected(false));
}
});
}
Added the onSelectionChanged() event listener for the detail grid.
constructor() {
this.gridOptions = {
...
detailCellRendererParams: {
getDetailRowData: function(params) {
params.successCallback(params.data.items); // Defines where to find the detail fields out of the rowData object
},
detailGridOptions: {
rowSelection: 'multiple',
defaultColDef: {
sortable: true
},
getRowNodeId: function (rowData) {
return rowData.id; // detail items are indexed by id field
},
onSelectionChanged: function (params) {
console.log(this); // I expected this to print out my Angular component object, but instead it prints out this.gridOptions.detailCellRendererParams.detailGridOptions
console.log("TEST"); // I know that this function is successfully being called because this line is printed
this.selectedItems = 0;
params.api.forEachNode(detailRowNode => {
if(detailRowNode.isSelected()) {
this.selectedObs++; // I believe that this would work if I had access to the correct "this" context
}
});
},
columnDefs: [
{headerName: 'Column 1', field: 'column1', checkboxSelection: true},
{headerName: 'Column 2', field: 'column2'},
]
}
}
};
}

Answer 1

Here is an Angular example where you can push the parent component as a reference to the detail grid and set it as its context. Doing this allows you to register a component method as a callback for the detail grid's onRowSelected method.
https://stackblitz.com/edit/ag-grid-detailrow-selectcallback?file=src/app/app.component.ts

Answer 2

Move the onSelectionChanged(params) function to the same level as the detailCellRendererParams object.
internalOnSelectionChanged(params)
{
this.detailGridApi = params.api;
this.detailGridColumnApi = params.columnApi;
console.log(this);
}
Then, on the onSelectionChanged, do this:
onSelectionChanged: this.internalOnSelectionChanged.bind(this);
This solved my issues that were very similar to yours.