Sent a message to group from ejabberd server but i get
Hook user_receive_packet crashed when running
mod_mam:user_receive_packet
send_message(Type, From, To, Subject, Body, StaticNumber) ->
CodecOpts = ejabberd_config:codec_options(),
try xmpp:decode(
#xmlel{name = <<"message">>,
attrs = [{<<"to">>, To },
{<<"from">>,From},
{<<"type">>, Type},
{<<"id">>, p1_rand:get_string()}],
children =
[#xmlel{name = <<"subject">>,
children = [{xmlcdata, Subject}]},
#xmlel{name = <<"groupcontent">>,
attrs = [{<<"sendername">>, <<"Admin">>},
{<<"acknowStatus">>, <<"0">>},{<<"fromadmin">>, StaticNumber}],
children = []},
#xmlel{name = <<"body">>,
children = [{xmlcdata, Body}]}]},
?NS_CLIENT, CodecOpts) of
#message{from = JID} = Msg ->
State = #{jid => JID},
ejabberd_hooks:run_fold(user_send_packet, JID#jid.lserver, {Msg, State}, []),
ejabberd_router:route(Msg)
catch _:{xmpp_codec, Why} ->
{error, xmpp:format_error(Why)}
end.
function call :
send_message("normal",
list_to_binary("123456789#xmpp.designcafe.com"),
list_to_binary("6ff3d0a4-c281-41bd-a262-c65bd767014d#mix.xmpp.designcafe.com"),
list_to_binary("text"), <<"test">>, <<"123456789">>);
I could not fix above issue
send_message("normal",
Instead of "normal", you must provide groupchat as a binary, that is:
send_message(<<"groupchat">>,
What that change it works for me using ejabberd 22.05. It's important that From is an existing account, and it joined the MIX Channel. Of course the MIX Channel must exist too.
I'm trying to find URLs in a nested JSON response and map them. My function so far looks like this:
def list(env, id) do
Service.get_document(env, id)
|> Poison.decode!
|> Enum.find(fn {_key, val} -> String.starts_with?(val, 'https') end)
end
The JSON looks roughly like this:
"stacks": [
{
"boxes": [
{
"content": "https://ddd.cloudfront.net/photos/uploaded_images/000/001/610/original/1449447147677.jpg?1505956120",
"box": "photo"
}
]
}
],
"logo": "https://ddd.cloudfront.net/users/cmyk_banners/000/000/002/original/banner_CMYK.jpg?1397201875"
So URLs can have any key, and be at any level.
With that code I get this error:
no function clause matching in String.starts_with?/2
Anyone got a better way to find in JSON responses?
You'll have to use recursive function for this, which handles three types of data:
For map, it recurses over all its values.
For list, it recurses over all its elements.
For string, it selects strings that start with "https"
Here's a simple implementation which accepts a term and a string to check with starts_with?:
defmodule A do
def recursive_starts_with(thing, start, acc \\ [])
def recursive_starts_with(binary, start, acc) when is_binary(binary) do
if String.starts_with?(binary, start) do
[binary | acc]
else
acc
end
end
def recursive_starts_with(map, start, acc) when is_map(map) do
Enum.reduce(map, acc, fn {_, v}, acc -> A.recursive_starts_with(v, start, acc) end)
end
def recursive_starts_with(list, start, acc) when is_list(list) do
Enum.reduce(list, acc, fn v, acc -> A.recursive_starts_with(v, start, acc) end)
end
end
data = %{
"stacks" => [
%{
"boxes" => [
%{
"content" => "https://ddd.cloudfront.net/photos/uploaded_images/000/001/610/original/1449447147677.jpg?1505956120",
"box" => "photo"
}
]
}
],
"logo" => "https://ddd.cloudfront.net/users/cmyk_banners/000/000/002/original/banner_CMYK.jpg?1397201875"
}
data |> A.recursive_starts_with("https") |> IO.inspect
Output:
["https://ddd.cloudfront.net/photos/uploaded_images/000/001/610/original/1449447147677.jpg?1505956120",
"https://ddd.cloudfront.net/users/cmyk_banners/000/000/002/original/banner_CMYK.jpg?1397201875"]
I've succeeded in triggering a simple http request in ELM and decoding the JSON response into an ELM value - [https://stackoverflow.com/questions/43139316/decode-nested-variable-length-json-in-elm]
The problem I'm facing now-
How to chain (concurrency preferred) two http requests and merge the json into my new (updated) model. Note - please see the updated Commands.elm
Package used to access remote data - krisajenkins/remotedata http://package.elm-lang.org/packages/krisajenkins/remotedata/4.3.0/RemoteData
Github repo of my code - https://github.com/areai51/my-india-elm
Previous Working Code -
Models.elm
type alias Model =
{ leaders : WebData (List Leader)
}
initialModel : Model
initialModel =
{ leaders = RemoteData.Loading
}
Main.elm
init : ( Model, Cmd Msg )
init =
( initialModel, fetchLeaders )
Commands.elm
fetchLeaders : Cmd Msg
fetchLeaders =
Http.get fetchLeadersUrl leadersDecoder
|> RemoteData.sendRequest
|> Cmd.map Msgs.OnFetchLeaders
fetchLeadersUrl : String
fetchLeadersUrl =
"https://data.gov.in/node/85987/datastore/export/json"
Msgs.elm
type Msg
= OnFetchLeaders (WebData (List Leader))
Update.elm
update msg model =
case msg of
Msgs.OnFetchLeaders response ->
( { model | leaders = response }, Cmd.none )
Updated Code - (need help with Commands.elm)
Models.elm
type alias Model =
{ lsLeaders : WebData (List Leader)
, rsLeaders : WebData (List Leader) <------------- Updated Model
}
initialModel : Model
initialModel =
{ lsLeaders = RemoteData.Loading
, rsLeaders = RemoteData.Loading
}
Main.elm
init : ( Model, Cmd Msg )
init =
( initialModel, fetchLeaders )
Commands.elm
fetchLeaders : Cmd Msg
fetchLeaders = <-------- How do I call both requests here ? And fire separate msgs
Http.get fetchLSLeadersUrl lsLeadersDecoder <----- There will be a different decoder named rsLeadersDecoder
|> RemoteData.sendRequest
|> Cmd.map Msgs.OnFetchLSLeaders
fetchLSLeadersUrl : String
fetchLSLeadersUrl =
"https://data.gov.in/node/85987/datastore/export/json"
fetchRSLeadersUrl : String <------------------ New data source
fetchRSLeadersUrl =
"https://data.gov.in/node/982241/datastore/export/json"
Msgs.elm
type Msg
= OnFetchLSLeaders (WebData (List Leader))
| OnFetchRSLeaders (WebData (List Leader)) <-------- New message
Update.elm
update msg model =
case msg of
Msgs.OnFetchLSLeaders response ->
( { model | lsLeaders = response }, Cmd.none )
Msgs.OnFetchRSLeaders response -> <--------- New handler
( { model | rsLeaders = response }, Cmd.none )
The way to fire off two concurrent requests is to use Cmd.batch:
init : ( Model, Cmd Msg )
init =
( initialModel, Cmd.batch [ fetchLSLeaders, fetchRSLeaders ] )
There is no guarantee on which request will return first and there is no guarantee that they will both be successful. One could fail while the other succeeds, for example.
You mention that you want to merge the results, but you didn't say how the merge would work, so I'll just assume you want to append the lists of leaders together in one list, and it will be useful to your application if you had only to deal with a single RemoteData value rather than multiple.
You can merge multiple RemoteData values together with a custom function using map and andMap.
mergeLeaders : WebData (List Leader) -> WebData (List Leader) -> WebData (List Leader)
mergeLeaders a b =
RemoteData.map List.append a
|> RemoteData.andMap b
Notice that I'm using List.append there. That can really be any function that takes two lists and merges them however you please.
If you prefer an applicative style of programming, the above could be translated to the following infix version:
import RemoteData.Infix exposing (..)
mergeLeaders2 : WebData (List Leader) -> WebData (List Leader) -> WebData (List Leader)
mergeLeaders2 a b =
List.append <$> a <*> b
According to the documentation on andMap (which uses a result tuple rather than an appended list in its example):
The final tuple succeeds only if all its children succeeded. It is still Loading if any of its children are still Loading. And if any child fails, the error is the leftmost Failure value.
I am making a F# project and need to do some database queries to an online mysql db. Can anyone please help me. I need something like this
\\ Connect to DB
let servername = "localhost"
let username = "username"
let password = "password"
\\ Code that connects to db
\\ Print error message if can connect
\\ Query
let query = "SELECT * FROM table ..."
\\ Code that executes query
\\ Error Message if query not executed
You should install the .NET driver for MySQL. Then install the SQLprovider. There are samples for MySQL in the docs. You would connect to the db and query it like this:
type sql = SqlDataProvider<
dbVendor,
connString,
ResolutionPath = resPath,
IndividualsAmount = indivAmount,
UseOptionTypes = useOptTypes,
Owner = "HR"
>
let ctx = sql.GetDataContext()
let employees =
ctx.Hr.Employees
|> Seq.map (fun e -> e.ColumnValues |> Seq.toList)
|> Seq.toList
connstring will be something like this:
[<Literal>]
let connString = "Server=localhost;Database=HR;User=root;Password=password"
You should also read https://msdn.microsoft.com/visualfsharpdocs/conceptual/walkthrough-accessing-a-sql-database-by-using-type-providers-%5bfsharp%5d
I would also say SQLProvider is the way to go as then you have a validation of your logics against your database and you notice if your database changes.
But you can connect manually if you want to:
// Reference Nuget package MySql.Data
//#r #"./../packages/MySql.Data/lib/net40/MySql.Data.dll"
open System
open MySql.Data.MySqlClient
let cstr = "server = localhost; database = myDatabase; uid = username;pwd = password"
let ExecuteSqlAsync (query : string) parameters =
use rawSqlConnection = new MySqlConnection(cstr)
async {
do! rawSqlConnection.OpenAsync() |> Async.AwaitIAsyncResult |> Async.Ignore
use command = new MySqlCommand(query, rawSqlConnection)
parameters |> List.iter(fun (par:string*string) -> command.Parameters.AddWithValue(par) |> ignore)
let! affectedRows = command.ExecuteNonQueryAsync() |> Async.AwaitTask
match affectedRows with
| 0 -> "ExecuteSql 0 rows affected: " + query |> Console.WriteLine
()
| x -> ()
}
let ExecuteSql (query : string) parameters =
use rawSqlConnection = new MySqlConnection(cstr)
rawSqlConnection.Open()
use command = new MySqlCommand(query, rawSqlConnection)
parameters |> List.iter(fun (par:string*string) -> command.Parameters.AddWithValue(par) |> ignore)
let affectedRows = command.ExecuteNonQuery()
match affectedRows with
| 0 -> "ExecuteSql 0 rows affected: " + query |> Console.WriteLine
()
| x -> ()
I test with this code :
get_fee(Transaction,SourceNumber,Amount, Currency) ->
Url = lists:concat(["http://localhost/test.php","?transaction=", Transaction, "&saccount=", SourceNumber,Amount,"¤cy=",Currency]),
inets:start(),
{Flag, Response} = http:request(get, {Url, []}, [], []),
case Flag of
ok ->
{ { _, ReturnCode, _ }, _, Body } = Response,
if ReturnCode =:= 200 ->
{ok,{_,[{_,Code},{_,Permission},{_,Payer},{_,Payee}]}} = json:decode_string(Body),
case Permission of true ->
if Code =:= 200 ->
{ok,{Code, Payer, Payee}};
Code =:= 204 ->
{nok,{Code, not_found}};
true ->
{nok,{Code, parameter_error}}
end;
false ->
{nok,{Code, parameter_error}}
end;
true->
{error, http_error}
end;
error ->
case Response of
nxdomain -> {error, dns_error};
_ -> {error, network_error}
end
end.
the response from the http is : {"code":200,"permission":true,"fee_payer":0,"fee_payee":19}
But now I like to do the same think but the return of http in this case for example is :
{"CIN":"08321224","Name":21}
so I have just CIN and Name in this case
I try to change the previous
get_fee(Num) ->
Url = lists:concat(["http://localhost/GTW/Operation.php","?ACCOUNT_NUM=", Num]),
inets:start(),
{Flag, Response} = http:request(get, {Url, []}, [], []),
case Flag of
ok ->
{ { _, ReturnCode, _ }, _, Body } = Response,
%% for debug
io:format("~p~n",[ReturnCode]),
if ReturnCode =:= "08321224" ->
{ok,{_,[{_,CIN},{_,Name}]}} = json:decode_string(Body),
case Name of 21 ->
io:format(CIN),
io:format(Name),
if CIN =:= "08321224"->
{ok,{CIN, Name}};
CIN =:= 204 ->
{nok,{CIN, not_found}};
true ->
{nok,{CIN, parameter_error}}
end;
false ->
{nok,{CIN, parameter_error}}
end;
true->
{error, http_error}
end;
error ->
case Response of
nxdomain -> {error, dns_error};
_ -> {error, network_error}
%% for debug
%%io:format("pass2~n ~p~n",[Response]),
end
end.
but it displys :
test:get_fee("0001").
200
{error,http_error}
So I'll nitpick on the style here, because you will be far better off if you follow the semantical idea of Erlang:
get_fee(Num) ->
Url = lists:concat(["http://localhost/GTW/Operation.php","?ACCOUNT_NUM=", Num]),
inets:start(),
This is the wrong place to start inets. It should be started outside this function as you only need to
do this one.
{Flag, Response} = http:request(get, {Url, []}, [], []),
This part is better coded with a pattern match. The discrimination of Flag and Response can
be decoded directly with a simple match. Write,
case http:request(get, {Url, []}, [], []) of
{ok, {{_, 200, _}, _, Body}} ->
{ok, R} = json:decode_string(Body),
get_fee_decode_(get_cin(R), get_name(R));
{error, Reason} -> {error, Reason}
end.
I would recommend against changing {error, nxdomain} to {error, dns_error} since nxdomain perfectly
codes this case in any case. Just pass the error tuple to the caller and have him handle it.
get_fee_decode_("08321224" = CIN, 21 = Name) -> {ok, {CIN, Name}};
get_fee_decode_("204" = CIN, 21) -> {nok, {CIN, not_found}};
get_fee_decode_(CIN, _Name) -> {nok, {CIN, parameter_error}};
Introduce a new function like this to handle the inner parts of your code base. And hoist the matching to
top-level. This helps in the long run by decoupling your code into functions.
Do note that in a JSON structure, there is no order on an "object" so you can't assume that the structure is
{"code":200,"permission":true,"fee_payer":0,"fee_payee":19}
But a decode does not have to preserve this structure, according to JSON. So a valid decode may be:
[{"fee_payee", 19}, {"fee_payer", 0}, {"permission", true}, {"code", 200}]
This will fail to match in your code and you are setting yourself up for some nasty errors later on.
You want something along the lines of:
get_fee_payer(PL) -> proplists:get_value("fee_payer", PL).
Another thing which will be a problem with your programming style is that you are hiding error-information cases. In Erlang, you can often get away with only handling the "happy path" through the code and leave all the error handling out until you know what kind of errors are there in the code base. Then you can begin adding in error handling slowly. Defensive programming is not a thing you should be doing if you can avoid it.
You changed:
if ReturnCode =:= 200 ->
to:
if ReturnCode =:= "08321224" ->
However, that needs to stay the same in your version. 200 is the HTTP status code for "OK" - the first step here is to verify that the server actually processed the request and returned a positive reply. You'll find that number only in Body - that is what the if CIN =:= "08321224"-> part is for.