Customizing Grid Columns for Child Tables

When a child table doctype is shared across multiple parent doctypes, the visible columns are typically controlled by user settings (per user/parent-doctype/child-doctype) or the child's in_list_view fields. To force a specific set of columns per parent doctype, override the grid's setup_user_defined_columns method in the parent form's on_setup hook.

Implementation

In the parent doctype's client script (e.g., sales_order.js), use the following pattern in the onload function:

onload: (frm) => {
    const child_grid = frm.fields_dict.child_fieldname.grid;  // Replace 'child_fieldname' with your table field name
    if (child_grid) {
        child_grid.df.on_setup = function(grid) {
            // Override the method to force custom columns, ignoring user settings
            grid.setup_user_defined_columns = function() {
                this.user_defined_columns = [
                    frappe.meta.get_docfield("Child Doctype", "fieldname1"),
                    frappe.meta.get_docfield("Child Doctype", "fieldname2"),
                    // Add more fields as needed
                ].map(df => {
                    df.in_list_view = 1;
                    df.columns = 1;  // Adjust column width (1-12 Bootstrap units)
                    return df;
                });
            };
        };
        // Refresh to apply the override
        child_grid.refresh();
    }
}

How It Works

• The on_setup hook runs early in grid initialization.

• Overriding setup_user_defined_columns ensures custom columns are used instead of default/user-defined ones.

• This applies per grid instance (per parent form) without modifying core code.

• Column widths are controlled via df.columns; the grid auto-adjusts if total width < 12.

Example

For a "BOM Item" child table in a "Sales Order" form, showing only "charge", "rate", "amount", and "charge_amount":

onload: (frm) => {
    const bom_items_grid = frm.fields_dict.items.grid;
    if (bom_items_grid) {
        bom_items_grid.df.on_setup = function(grid) {
            grid.setup_user_defined_columns = function() {
                this.user_defined_columns = [
                    frappe.meta.get_docfield("BOM Item", "charge"),
                    frappe.meta.get_docfield("BOM Item", "rate"),
                    frappe.meta.get_docfield("BOM Item", "amount"),
                    frappe.meta.get_docfield("BOM Item", "charge_amount")
                ].map(df => {
                    df.in_list_view = 1;
                    df.columns = 1;
                    return df;
                });
            };
        };
        bom_items_grid.refresh();
    }
}

Notes

• Test by checking frm.fields_dict.child_fieldname.grid.user_defined_columns in the console.

• For editable grids, ensure fields are appropriately visible.

• If dynamic columns are needed based on form data, add conditional logic in the override.