Method exec_js

mongoengine/queryset/base.py:1509–1548

Execute a Javascript function on the server. A list of fields may be provided, which will be translated to their correct names and supplied as the arguments to the function. A few extra variables are added to the function's scope: ``collection``, which is the name of the

(self, code, *fields, **options)

            )

    def exec_js(self, code, *fields, **options):
        """Execute a Javascript function on the server. A list of fields may be
        provided, which will be translated to their correct names and supplied
        as the arguments to the function. A few extra variables are added to
        the function's scope: ``collection``, which is the name of the
        collection in use; ``query``, which is an object representing the
        current query; and ``options``, which is an object containing any
        options specified as keyword arguments.

        As fields in MongoEngine may use different names in the database (set
        using the :attr:`db_field` keyword argument to a :class:`Field`
        constructor), a mechanism exists for replacing MongoEngine field names
        with the database field names in Javascript code. When accessing a
        field, use square-bracket notation, and prefix the MongoEngine field
        name with a tilde (~).

        :param code: a string of Javascript code to execute
        :param fields: fields that you will be using in your function, which
            will be passed in to your function as arguments
        :param options: options that you want available to the function
            (accessed in Javascript through the ``options`` object)
        """
        queryset = self.clone()

        code = queryset._sub_js_fields(code)

        fields = [queryset._document._translate_field_name(f) for f in fields]
        collection = queryset._document._get_collection_name()

        scope = {"collection": collection, "options": options or {}}

        query = queryset._query
        if queryset._where_clause:
            query["$where"] = queryset._where_clause

        scope["query"] = query
        code = Code(code, scope=scope)

        db = queryset._document._get_db()
        return db.command("eval", code, args=fields).get("retval")

    def where(self, where_clause):
        """Filter ``QuerySet`` results with a ``$where`` clause (a Javascript