brotherton-erpnext/docs/dev/custom_script_examples/docs.dev.custom_script.validate2.md

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Restrict User Based on Child Record (Warehouse)

// restrict certain warehouse to Material Manager 
cur_frm.cscript.custom_validate = function(doc) {
    if(user_roles.indexOf("Material Manager")==-1) {

        var restricted_in_source = wn.model.get("Stock Entry Detail", 
            {parent:cur_frm.doc.name, s_warehouse:"Restricted"});

        var restricted_in_target = wn.model.get("Stock Entry Detail", 
            {parent:cur_frm.doc.name, t_warehouse:"Restricted"})

        if(restricted_in_source.length || restricted_in_target.length) {
            msgprint("Only Material Manager can make entry in Restricted Warehouse");
            validated = false;
        }
    }
}