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I get json text returned from an api call and I run it trough a script JSON Serialization and Deserialization from here https://www.mql5.com/en/code/13663.

My issue is that it only process the first few parts of the json because of what I believe to a linebreak/carriage inside the json structure. I dont get any error message, just an array containing everything before that line break.

I dont want to remove the line breaks inside the text fields in the json, only the returns inside the json structure. It is in the place each time just after {"ok":true,"result":[{"update_id":568022212,

Here is a full section

{"ok":true,"result":[{"update_id":568022212,
"channel_post":{"message_id":436,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},"date":1588899840,"reply_to_message":{"message_id":372,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},"date":1588838583,"text":"A\nGbpusd buy now 1.2360\nSl 1.2280 \nTp open\n","entities":[{"offset":52,"length":11,"type":"mention"}]},"text":"A\n42 pips bookd close\ud83d\udfe2\ud83d\udfe2"}},{"update_id":568022213,
"channel_post":{"message_id":437,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},"date":1588900321,"reply_to_message":{"message_id":435,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},"date":1588893671,"text":"A\nGold buy 1713.3\nSl 1702 \nTp open\nSwing trade"},"text":"Amazon\n60 pips bookd close\ud83d\udfe2\ud83d\udfe2"}},{"update_id":568022214,
"channel_post":{"message_id":438,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},

MQL4 code:

 int   GetUpdates()
     {
      if(m_token==NULL)
         return(ERR_TOKEN_ISEMPTY);

      string out;
      string url=StringFormat("%s/bot%s/getUpdates",TELEGRAM_BASE_URL,m_token);
      string params=StringFormat("offset=%d",m_update_id);
      //---
      int res=PostRequest(out,url,params,WEB_TIMEOUT);
      if(res==0)
        {

         Print(StringDecode(out));
         //--- parse result
         CJAVal js(NULL,jtUNDEF);
         bool done=js.Deserialize(out);
         if(!done)
            return(ERR_JSON_PARSING);

         bool ok=js["ok"].ToBool();
         if(!ok)
            return(ERR_JSON_NOT_OK);

         CCustomMessage msg;

         int total=ArraySize(js["result"].m_e);
         for(int i=0; i<total; i++)
           {
            CJAVal item=js["result"].m_e[i];
            //---
            msg.update_id=item["update_id"].ToInt();

            //---
            msg.message_id=item["message"]["message_id"].ToInt();
            msg.message_date=(datetime)item["message"]["date"].ToInt();
            //---
            msg.message_text=item["message"]["text"].ToStr();
            printf((datetime)item["message"]["date"].ToInt());
            msg.message_text=StringDecode(msg.message_text);
            //---
            msg.from_id=item["message"]["from"]["id"].ToInt();

            msg.from_first_name=item["message"]["from"]["first_name"].ToStr();
            msg.from_first_name=StringDecode(msg.from_first_name);

            msg.from_last_name=item["message"]["from"]["last_name"].ToStr();
            msg.from_last_name=StringDecode(msg.from_last_name);

            msg.from_username=item["message"]["from"]["username"].ToStr();
            msg.from_username=StringDecode(msg.from_username);
            //---
            msg.chat_id=item["message"]["chat"]["id"].ToInt();

            msg.chat_first_name=item["message"]["chat"]["first_name"].ToStr();
            msg.chat_first_name=StringDecode(msg.chat_first_name);

            msg.chat_last_name=item["message"]["chat"]["last_name"].ToStr();
            msg.chat_last_name=StringDecode(msg.chat_last_name);

            msg.chat_username=item["message"]["chat"]["username"].ToStr();
            msg.chat_username=StringDecode(msg.chat_username);
Keith Power
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1 Answers1

1

I tried to use the same library, it seems to have a bug with parsing arrays. That is why I used https://www.mql5.com/en/code/11134. It has a disadvantage: you need to delete all the objects, unfortunately; as a result there's plenty of code. But at least it works.

Seems your json has incorrect format, I used to cut it a little.

  #include <json1.mqh> //modified version, https://www.mql5.com/en/forum/28928/page5#comment_15766620

  //const string post_result=
  //{"ok":true,"result":[
  //{"update_id":568022212,"channel_post":{"message_id":436,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},
  //"date":1588899840,"reply_to_message":{"message_id":372,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},
  //"date":1588838583,"text":"A\nGbpusd buy now 1.2360\nSl 1.2280 \nTp open\n","entities":[{"offset":52,"length":11,"type":"mention"}]},"text":"A\n42 pips bookd close\ud83d\udfe2\ud83d\udfe2"}},
  //{"update_id":568022213,"channel_post":{"message_id":437,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},
  //"date":1588900321,"reply_to_message":{"message_id":435,"chat":{"id":-1001436032340,"title":"FORTUNA","type":"channel"},
  //"date":1588893671,"text":"A\nGold buy 1713.3\nSl 1702 \nTp open\nSwing trade"},"text":"Amazon\n60 pips bookd close\ud83d\udfe2\ud83d\udfe2" }}]}
  //;


void function()
  {
//---
  const string post_result=getContent();//ok, you managed to get some string here

  JSONParser *parser=new JSONParser();
  JSONValue *value=parser.parse(post_result);
  delete(parser);
  if(CheckPointer(value)==POINTER_INVALID)
    {
     printf("%i %s: error!",__LINE__,__FILE__);
     delete(value);
     return;
    }
  JSONObject *obj=(JSONObject*)value;
  const bool isSuccess=obj.getBool("ok");
  printf("%i %s: isSuccess=%d",__LINE__,__FILE__,isSuccess);
  if(!isSuccess)return;

  JSONValue *resultValue=obj.getValue("result");
  if(CheckPointer(resultValue)!=POINTER_INVALID)
    {
     JSONArray *resultValueArray=resultValue;
     for(int i=0;i<resultValueArray.size();i++)
       {
        printf("%i %s: #%d=%s",__LINE__,__FILE__,i,resultValueArray.getObject(i).toString());
        //you can work with JSONObject or with string, whatever is more convenient
        parseResultLine(resultValueArray.getObject(i));
       }
     delete(resultValueArray);
    }
  delete(resultValue);
  delete(obj);
}   
  bool parseResultLine(JSONObject *object)
    {
     const long update_id=object.getLong("update_id");
     JSONObject *channel_post=object.getObject("channel_post");

     const long message_id=channel_post.getLong("message_id");
     const datetime date=(datetime)channel_post.getInt("date");
     const string text=channel_post.getString("text");
  printf("%i %s: id=%s, dt=%d/%s, text=%s",__LINE__,__FILE__,IntegerToString(message_id),(int)date,TimeToString(date),text);
     JSONObject *chat=channel_post.getObject("chat");
     const long chat_id=chat.getLong("id");
     const string chat_title=chat.getString("title");
  printf("%i %s: chat-> id=%I64d title=%s type=%s",__LINE__,__FILE__,chat_id,chat_title,chat.getString("type"));
     JSONObject *reply=channel_post.getObject("reply_to_message");
  printf("%i %s: replied: id=%s, date=%s",__LINE__,__FILE__,string(reply.getLong("message_id")),TimeToString(reply.getInt("date")));

     return true;
    }
Daniel Kniaz
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  • Thanks for the reply. Unfortunately I am getting an error on the very last line `'#endif' - unexpected token`. Did you come across this yourself? – Keith Power May 09 '20 at 20:17
  • Hi Daniel, I have just commented the endif out and all working thank you. One last question if I can. I have tried to Google on how to get the fields from the object like I have in my question but I am confused. Do you have a short example. Thanks – Keith Power May 09 '20 at 22:46
  • @KeithPower Okay, I updated my example, please have a look. Not all of your fields are there, but I hope that would be enough to understand the concept. `printf` will help to understand the rest :) – Daniel Kniaz May 10 '20 at 08:41
  • amazing thanks. I have a much better insight into `objects` – Keith Power May 10 '20 at 12:26