/modules/mod_base/filters/filter_random.erl

 1%% @author Marc Worrell <marc@worrell.nl>
 2%% @copyright 2010 Marc Worrell
 3%% @doc 'random' filter, return a random element of a list
 4
 5%% Copyright 2010 Marc Worrell
 6%%
 7%% Licensed under the Apache License, Version 2.0 (the "License");
 8%% you may not use this file except in compliance with the License.
 9%% You may obtain a copy of the License at
10%% 
11%%     http://www.apache.org/licenses/LICENSE-2.0
12%% 
13%% Unless required by applicable law or agreed to in writing, software
14%% distributed under the License is distributed on an "AS IS" BASIS,
15%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16%% See the License for the specific language governing permissions and
17%% limitations under the License.
18
19-module(filter_random).
20-export([random/2]).
21
22
23random([], _Context) ->
24    undefined;
25random(undefined, _Context) ->
26    undefined;
27random(In, Context) when is_list(In) ->
28    M = filter_rand:rand(length(In), Context),
29    hd(lists:nthtail(M-1, In));
30random(In, Context) ->
31    random(erlydtl_runtime:to_list(In, Context), Context).