React native 尝试在chrome开发控制台中查看网络请求时Elixir后端出错

-我需要在react native中实现这行代码，以便在chrome开发控制台中查看我的网络请求：

GLOBAL.XMLHttpRequest = GLOBAL.originalXMLHttpRequest || GLOBAL.XMLHttpRequest

但当我这样做时，我从前端发送到本地主机Elixir后端的请求会产生以下错误：

15:48:41.502 [error] #PID<0.406.0> running Api.Router terminated
Server: 192.168.20.3:4000 (http)
Request: GET /favicon.ico
** (exit) an exception was raised:
    ** (FunctionClauseError) no function clause matching in Api.Router.do_match/4
        (api) lib/api/router.ex:14: Api.Router.do_match(%Plug.Conn{adapter: {Plug.Adapters.
Cowboy.Conn, :...}, assigns: %{}, before_send: [], body_params: %Plug.Conn.Unfetched{aspect
: :body_params}, cookies: %Plug.Conn.Unfetched{aspect: :cookies}, halted: false, host: "192
.168.20.3", method: "GET", owner: #PID<0.406.0>, params: %Plug.Conn.Unfetched{aspect: :para
ms}, path_info: ["favicon.ico"], path_params: %{}, peer: {{192, 168, 20, 3}, 58348}, port:
4000, private: %{}, query_params: %Plug.Conn.Unfetched{aspect: :query_params}, query_string
: "", remote_ip: {192, 168, 20, 3}, req_cookies: %Plug.Conn.Unfetched{aspect: :cookies}, re
q_headers: [{"host", "192.168.20.3:4000"}, {"connection", "keep-alive"}, {"user-agent", "Mo
zilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome
/58.0.3029.110 Safari/537.36"}, {"accept", "image/webp,image/*,*/*;q=0.8"}, {"referer", "ht
tp://192.168.20.3:4000/categories"}, {"accept-encoding", "gzip, deflate, sdch"}, {"accept-l
anguage", "en-GB,en-US;q=0.8,en;q=0.6"}, {"origin", "http://evil.com/"}], request_path: "/f
avicon.ico", resp_body: nil, resp_cookies: %{}, resp_headers: [{"cache-control", "max-age=0
, private, must-revalidate"}], scheme: :http, script_name: [], secret_key_base: nil, state:
 :unset, status: nil}, "GET", ["favicon.ico"], "192.168.20.3")
        (api) lib/api/router.ex:1: Api.Router.plug_builder_call/2
        (api) lib/plug/debugger.ex:123: Api.Router.call/2
        (plug) lib/plug/adapters/cowboy/handler.ex:15: Plug.Adapters.Cowboy.Handler.upgrade
/4
        (cowboy) /Users/Ben/Development/Projects/vepo/api/deps/cowboy/src/cowboy_protocol.e
rl:442: :cowboy_protocol.execute/4

现在它发生在

get”/categories/“do

问题顶行代码的主要变化是，这意味着我必须启用CORS，这是我使用浏览器插件所做的，所以Elixir可能不喜欢这样。

我补充说：

  get "/favicon.ico" do
    # Api.Repo.getCategories(conn)
  end

现在的错误是：

17:17:05.354 [error] #PID<0.370.0> running Api.Router terminated
Server: 192.168.20.3:4000 (http)
Request: OPTIONS /categories
** (exit) an exception was raised:
    ** (FunctionClauseError) no function clause matching in Api.Router.do_match/4
        (api) lib/api/router.ex:13: Api.Router.do_match(%Plug.Conn{adapter: {Plug.Adapters.
Cowboy.Conn, :...}, assigns: %{}, before_send: [], body_params: %Plug.Conn.Unfetched{aspect
: :body_params}, cookies: %Plug.Conn.Unfetched{aspect: :cookies}, halted: false, host: "192
.168.20.3", method: "OPTIONS", owner: #PID<0.370.0>, params: %Plug.Conn.Unfetched{aspect: :
params}, path_info: ["categories"], path_params: %{}, peer: {{192, 168, 20, 3}, 50258}, por
t: 4000, private: %{}, query_params: %Plug.Conn.Unfetched{aspect: :query_params}, query_str
ing: "", remote_ip: {192, 168, 20, 3}, req_cookies: %Plug.Conn.Unfetched{aspect: :cookies},
 req_headers: [{"host", "192.168.20.3:4000"}, {"connection", "keep-alive"}, {"access-contro
l-request-method", "GET"}, {"origin", "http://evil.com/"}, {"user-agent", "Mozilla/5.0 (Mac
intosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110
 Safari/537.36"}, {"access-control-request-headers", "x-requested-with"}, {"accept", "*/*"}
, {"referer", "http://localhost:8081/debugger-ui"}, {"accept-encoding", "gzip, deflate, sdc
h"}, {"accept-language", "en-GB,en-US;q=0.8,en;q=0.6"}], request_path: "/categories", resp_
body: nil, resp_cookies: %{}, resp_headers: [{"cache-control", "max-age=0, private, must-re
validate"}], scheme: :http, script_name: [], secret_key_base: nil, state: :unset, status: n
il}, "OPTIONS", ["categories"], "192.168.20.3")
        (api) lib/api/router.ex:1: Api.Router.plug_builder_call/2
        (api) lib/plug/debugger.ex:123: Api.Router.call/2
        (plug) lib/plug/adapters/cowboy/handler.ex:15: Plug.Adapters.Cowboy.Handler.upgrade
/4
        (cowboy) /Users/Ben/Development/Projects/vepo/api/deps/cowboy/src/cowboy_protocol.e
rl:442: :cowboy_protocol.execute/4

17:17:05.354[错误]#正在运行Api的PID。路由器已终止
服务器：192.168.20.3:4000（http）
请求：选项/类别
**（退出）引发了一个异常：
**（FunctionClauseError）Api.Router.do_match/4中没有匹配的函数子句
（api）lib/api/router.ex:13:api.router.do_match（%Plug.Conn{adapter:{Plug.Adapters。
Cowboy.Conn，：…}，赋值：%{}，在发送之前：[]，body参数：%Plug.Conn.Unfetched{aspect
：：body_params}，cookies:%Plug.Conn.Unfetched{aspect:：cookies}，暂停：false，主机：192
.168.20.3”，方法：“选项”，所有者：#PID，参数：%Plug.Conn.Unfetched{aspect:：
params}，path_info:[“categories”]，path_params:%{}，peer:{{192,168,20,3}，50258}，por
t:4000，私有：%{}，查询参数：%Plug.Conn.Unfetched{aspect:：query\u params}，查询参数
ing:，远程ip:{192，168，20，3}，请求cookies:%Plug.Conn.Unfetched{aspect:：cookies}，
请求头：[{“主机”，“192.168.20.3:4000”}，{“连接”，“保持活动”}，{“访问控制”
l-request-method“，”GET“}，{”origin“，”http://evil.com/“}，{”用户代理“，”Mozilla/5.0（Mac
intosh；英特尔Mac OS X 10_12_4）AppleWebKit/537.36（KHTML，类似Gecko）Chrome/58.0.3029.110
Safari/537.36“}，{”访问控制请求头“，”x-request-with“}，{”accept“，“*/*”}
，{“referer”http://localhost:8081/debugger-ui“}，{”接受编码“，”gzip，deflate，sdc
h“}，{“接受语言”，“en GB，en US；q=0.8，en；q=0.6”}]，请求路径：“/categories”，分别为_
正文：nil，resp_cookies:%{}，resp_头：[{“缓存控制”，“最大年龄=0，私有，必须重新设置”
验证“}]，方案：：http，脚本名称：[]，密钥基：nil，状态：：unset，状态：n
il}，“选项”，“类别”，“192.168.20.3”）
（api）lib/api/router.ex:1:api.router.plug\u builder\u call/2
（api）lib/plug/debugger.ex:123:api.Router.call/2
（plug）lib/plug/adapters/cowboy/handler.ex:15:plug.adapters.cowboy.handler.upgrade
/4
（牛仔）/Users/Ben/Development/Projects/vepo/api/deps/cowboy/src/cowboy_protocol.e
rl:442:：cowboy_protocol.execute/4

这个错误也一再出现：

17:16:48.032 [error] GenServer #PID<0.332.0> terminating
** (stop) exited in: GenServer.call(Postgrex.TypeManager, {:get, Ecto.Adapters.Postgres.Typ
eModule, {'localhost', 5432, "api_repo"}}, 5000)
    ** (EXIT) time out
    (elixir) lib/gen_server.ex:737: GenServer.call/3
    (postgrex) lib/postgrex/protocol.ex:621: Postgrex.Protocol.bootstrap/3
    (postgrex) lib/postgrex/protocol.ex:475: Postgrex.Protocol.handshake/2
    (db_connection) lib/db_connection/connection.ex:134: DBConnection.Connection.connect/2
    (connection) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol

17:16:48.032 [error] GenServer #PID<0.329.0> terminating
** (stop) exited in: GenServer.call(Postgrex.TypeManager, {:get, Ecto.Adapters.Postgres.Typ
eModule, {'localhost', 5432, "api_repo"}}, 5000)
    ** (EXIT) time out
    (elixir) lib/gen_server.ex:737: GenServer.call/3
    (postgrex) lib/postgrex/protocol.ex:621: Postgrex.Protocol.bootstrap/3
    (postgrex) lib/postgrex/protocol.ex:475: Postgrex.Protocol.handshake/2
    (db_connection) lib/db_connection/connection.ex:134: DBConnection.Connection.connect/2
    (connection) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol

17:16:48.032[错误]GenServer#PID终止
**（停止）退出：GenServer.call（Postgrex.TypeManager，{:get，exto.Adapters.Postgres.Typ
eModule，{'localhost'，5432，“api_repo}}，5000）
**（退出）超时
（elixir）lib/gen_server.ex:737:GenServer.call/3
（postgrex）lib/postgrex/protocol.ex:621:postgrex.protocol.bootstrap/3
（postgrex）lib/postgrex/protocol.ex:475:postgrex.protocol.handshake/2
（db_connection）lib/db_connection/connection.ex:134:DBConnection.connection.connect/2
（connection）lib/connection.ex:622:connection.enter_connect/5
（stdlib）proc_lib.erl:247:：proc_lib.init_p_do_apply/3
最后信息：无
国家：Postgrex.协议
17:16:48.032[错误]发电机服务器#PID终止
**（停止）退出：GenServer.call（Postgrex.TypeManager，{:get，exto.Adapters.Postgres.Typ
eModule，{'localhost'，5432，“api_repo}}，5000）
**（退出）超时
（elixir）lib/gen_server.ex:737:GenServer.call/3
（postgrex）lib/postgrex/protocol.ex:621:postgrex.protocol.bootstrap/3
（postgrex）lib/postgrex/protocol.ex:475:postgrex.protocol.handshake/2
（db_connection）lib/db_connection/connection.ex:134:DBConnection.connection.connect/2
（connection）lib/connection.ex:622:connection.enter_connect/5
（stdlib）proc_lib.erl:247:：proc_lib.init_p_do_apply/3
最后信息：无
国家：Postgrex.协议

该错误是由于请求

/favicon.ico

。您可以忽略它，或者添加一个提供服务的

get”/favicon.ico“

，或者将一个

favicon.ico

图标文件放到web根目录中。@Dogbert谢谢！该错误并不严重，但有一个严重错误，因为它不再获取类别。我在问题的底部贴了一个（希望）更有用的错误。@Dogbert并在问题的底部贴了另一个错误question@Dogbert我刚刚将

options”/categories/“do Api.Repo.getCategories（conn）end

添加到

router.ex

中，现在它可以工作了。干杯

17:16:48.032 [error] GenServer #PID<0.332.0> terminating
** (stop) exited in: GenServer.call(Postgrex.TypeManager, {:get, Ecto.Adapters.Postgres.Typ
eModule, {'localhost', 5432, "api_repo"}}, 5000)
    ** (EXIT) time out
    (elixir) lib/gen_server.ex:737: GenServer.call/3
    (postgrex) lib/postgrex/protocol.ex:621: Postgrex.Protocol.bootstrap/3
    (postgrex) lib/postgrex/protocol.ex:475: Postgrex.Protocol.handshake/2
    (db_connection) lib/db_connection/connection.ex:134: DBConnection.Connection.connect/2
    (connection) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol

17:16:48.032 [error] GenServer #PID<0.329.0> terminating
** (stop) exited in: GenServer.call(Postgrex.TypeManager, {:get, Ecto.Adapters.Postgres.Typ
eModule, {'localhost', 5432, "api_repo"}}, 5000)
    ** (EXIT) time out
    (elixir) lib/gen_server.ex:737: GenServer.call/3
    (postgrex) lib/postgrex/protocol.ex:621: Postgrex.Protocol.bootstrap/3
    (postgrex) lib/postgrex/protocol.ex:475: Postgrex.Protocol.handshake/2
    (db_connection) lib/db_connection/connection.ex:134: DBConnection.Connection.connect/2
    (connection) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol