json - 使用 rfc4627 从 erlang 中的 json 数组中获取特定数据

Question

这是我在运行以下 2 个命令后得到的输出。

Wc = os:cmd("curl -s -k -X GET 'http://10.210.12.158:10065/iot/get/task_id?id=1'"),
    WW = decode_json(Wc), 

输出 - -

{ok,{obj,[{"status",200},
    {"data",
        [{obj,[{"id",1},
           {"task",
                <<"Turn on the bulb when the temperature is greater than 28 ">>},
           {"working_condition",1},
           {"depending_value",<<"Temperature">>},
           {"device",<<" BulbOnly">>},
           {"turning_point",28},
           {"config_id",null}]}]}]}}

我想分别获取这些数据。

例如 - 任务 = 当温度大于 28 时打开灯泡

那么，我该怎么做呢？

Answer 1

这个返回的结构似乎返回了一个任务列表，每个任务都是一个 proplist，你可以做类似的事情

-module(test).
-export([input/0, get_tasks/1]).

input() ->
  {ok,{obj,[{"status",200},
    {"data",
        [{obj,[{"id",1},
           {"task",
                <<"Turn on the bulb when the temperature is greater than 28 ">>},
           {"working_condition",1},
           {"depending_value",<<"Temperature">>},
           {"device",<<" BulbOnly">>},
           {"turning_point",28},
           {"config_id",null}]}]}]}}.


get_tasks({ok, {obj, [_Status, {"data", Tasks}|_Tail]}}) ->
  [ get_task_description(T) || T <- Tasks ].

get_task_description({obj, Proplist}) ->
  proplists:get_value("task", Proplist).

在 shell 中运行它时，你会得到：

1> test:get_tasks(test:input()).
[<<"Turn on the bulb when the temperature is greater than 28 ">>]