Zotonic 1.0 - Template model for the OMDB movie database - source code to accompany the documentation

m_omdb.erl

-module(m_omdb).
-behaviour(zotonic_model).

-export([
    m_get/3
]).

-include_lib("zotonic_core/include/zotonic.hrl").

-define(API_URL, "http://www.omdbapi.com/?").

-spec m_get(Keys, Msg, Context) -> Return when
    Keys :: list(),
    Msg :: zotonic_model:opt_msg(),
    Return :: zotonic_model:return(),
    Context:: z:context().

% Syntax: m.omdb.api_url
m_get([ <<"api_url">> | Rest ], _Msg, _Context) ->
    {ok, {z_convert:to_binary(?API_URL), Rest}};

% Syntax: m.omdb["tt0123456789"]
m_get([ <<"tt", _/binary>> = Id | Rest ], _Msg, _Context) ->
    {ok, {fetch_data([ {id, Id} ]), Rest}};

% Syntax: m.omdb["some title"]
m_get([ Title | Rest ], _Msg, _Context) when is_binary(Title) ->
    {ok, {fetch_data([ {id, Id} ]), Rest}};

% Syntax: m.omdb.sometype["tt0123456789"]
m_get([ Type, <<"tt", _/binary>> = Id | Rest ], _Msg, _Context)
    when Type =:= <<"movies">>;
         Type =:= <<"series">>;
         Type =:= <<"episode">> ->
    {ok, {fetch_data([ {type, Type}, {id, Id} ]), _Msg, Rest}};

% Syntax: m.omdb.sometype[QueryString]
m_get([ Type, QueryString | Rest ], _Msg, _Context)
    when Type =:= <<"movies">>;
         Type =:= <<"series">>;
         Type =:= <<"episode">> ->
    {ok, {fetch_data([ {type, Type}, {title, QueryString} ]), Rest}};

% Syntax: m.omdb[{query QueryParams}]
% For m.omdb[{query title="Dollhouse"}], Query is: [{title,"Dollhouse"}]
m_get([ {query, Query} | Rest ], _Msg, _Context) ->
    {ok {fetch_data(Query), Rest}};

% Syntax: m.omdb.sometype[{query QueryParams}]
% For m.omdb.series[{query title="Dollhouse"}], Query is: [{title,"Dollhouse"}] and Q is: [{type,"series"}]
m_get([ Type, {query, Query} | Rest ], _Msg, _Context)
    when Type =:= <<"movies">>;
         Type =:= <<"series">>;
         Type =:= <<"episode">> ->
    {ok, {fetch_data([ {type, Type} | Query ]), Rest}}.



-spec fetch_data(Query) -> list() when Query:: list().
fetch_data([]) ->
    [{error, "Params missing"}];
fetch_data(Query) ->
    case proplists:is_defined(title, Query) or proplists:is_defined(id, Query) of
        false -> [{error, "Param id or title missing"}];
        true ->
            QueryParts = lists:map(fun(Q) ->
                make_query_string(Q)
            end, Query),
            Url = ?API_URL ++ string:join(QueryParts, "&"),
            case get_page_body(Url) of
                {error, Error} ->
                    [{error, Error}];
                Json ->
                    {struct, JsonData} = mochijson2:decode(Json),
                    lists:map(fun(D) ->
                        convert_data_prop(D)
                    end, JsonData)
            end
    end.


%% Translate query params id, title and type into parameters that OMDB wants
-spec make_query_string({Key, Value}) -> string() when
    Key:: atom(),
    Value:: binary() | string() | atom().
make_query_string({id, Id}) ->
    "i=" ++ z_url:url_encode(Id);
make_query_string({title, Title}) ->
    "t=" ++ z_url:url_encode(Title);
make_query_string({type, Type}) ->
    "type=" ++ z_url:url_encode(Type);
make_query_string(_) ->
    "".


%% Translate binary keys to atoms
-spec convert_data_prop({Key, Value}) -> {atom(), string()} when
    Key:: binary(),
    Value:: binary().
convert_data_prop({Key, Value}) ->
    {z_convert:to_atom(string:to_lower(z_convert:to_list(Key))), Value}.


get_page_body(Url) ->
    case httpc:request(get, {Url, []}, [], []) of
        {ok, {_, Headers, Body}} ->
            case content_length(Headers) of
                0 -> {error, "No content"};
                _ -> Body
            end;
        Error ->
            {error, Error}
    end.

content_length(Headers) ->
    list_to_integer(proplists:get_value("content-length", Headers, "0")).

Revised according to 1.0.0-rc.5/zotonic_model

@williamthome Thanks!

@williamthome Ok if I copy your version over to this gist?

@williamthome Ok if I copy your version over to this gist?

Of course! o/

Thanks, copied it!