ERPNext: Call custom app method using custom script

write this in custom script.

Custom Script

cur_frm.cscript.docs_required = function(doc, cdt, cdn) {
    cur_frm.call({
    "method": 'ef_fruits.ef_doc.ef_doc.apply_documents_requiredd',
     "args": {
           "docs_required": doc.docs_required,
        },
     callback: function(r) {
           if(!r.exc) {
           }
           }
})
};


python function in custom app.

@frappe.whitelist()
def apply_documents_required(docs_required):
    if self.documents_required_master:
        shipping_rule = frappe.get_doc("Documents Required Master", self.documents_required_master)
        frappe.msgprint("Hi @3")
        for condition in shipping_rule.get("documents_required_master"):
            doc_req = {
                "doctype": "Documents Required",
                "name_of_document": condition.name_of_document,
                "dispatch_address": condition.dispatch_address
            }
            frappe.msgprint(condition.name_of_document)
            frappe.msgprint(condition.dispatch_address)

 python function to append data in dict object.

@frappe.whitelist(allow_guest=True)
def apply_documents_required(self, method):
        doc_req = []
        if not self.documents_required and self.documents_required_master:
        doc_master = frappe.get_doc("Documents Required Master", self.documents_required_master)
        for value in doc_master.get("documents_required_master"):
            doc_req = {
                "doctype": "Documents Required",
                "name_of_document": value.name_of_document,
                "dispatch_address": value.dispatch_address,
                                "number_of_copies": value.number_of_copies
            }
                        self.append("documents_required", doc_req)


Note:
Above code will display of document name and document address.
You can return value from python function and set it into custom script.
I will write more on this later