Calculate Child Table Column and Sum it on Custom Field
frappe . ui . form . on ( 'Parent Doctype' , { refresh ( frm ) { frappe . ui . form . on ( 'Child Doctype' , { child_doctype_field : function ( frm , cdt , cdn ){ var d = locals [ cdt ][ cdn ] ; var totalx = 0 ; frm . doc .F ield_Name_in_Parent . forEach ( function ( d ) { totalx += flt ( d . child_doctype_field ) ; }) ; frm . set_value ( "custom_field" , totalx ) ; refresh_field ( "custom_field" ) ; }, table_4_remove : function ( frm , cdt , cdn ){ var d = locals [ cdt ][ cdn ] ; var totalx = 0 ; frm . doc . F ield_Name_in_Parent . forEach ( function ( d ) { totalx += flt ( d . child_doctype_field ) ; }) ; frm . set_value ( "custom_field" , totalx ) ; refresh_field ( "custom_field" ) ; } }) ; });