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JSON parsing with QtJson...

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  • Christian EhrlicherC Christian Ehrlicher

    @filipdns said in JSON parsing with QtJson...:

    what I have to do to extract the data what I need?...

    Extract the array I would guess... http://doc.qt.io/qt-5/qjsonarray.html

    F Offline
    F Offline
    filipdns
    wrote on last edited by
    #10

    @Christian-Ehrlicher I try to work with it like array:

    var obj =JSON.parse(res)
    console.log(obj.aircraft[0].geography)

    but the return message is [object Object]...

    kshegunovK 1 Reply Last reply
    0
    • Christian EhrlicherC Offline
      Christian EhrlicherC Offline
      Christian Ehrlicher
      Lifetime Qt Champion
      wrote on last edited by Christian Ehrlicher
      #11

      Sorry but I don't understand python that much to help you.

      Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
      Visit the Qt Academy at https://academy.qt.io/catalog

      1 Reply Last reply
      0
      • mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #12

        Hi

        {
          "aircraft":[
            {
              "geography":{
                "latitude":42.6581,
                "longitude":5.51009,
                "altitude":11585.4,
                "direction":16
              },
              "speed":{
                "horizontal":861.641,
                "isGround":0,
                "vertical":0
              },
              "departure":{
                "iataCode":"DJE",
                "icaoCode":"DTTJ"
              },
              "arrival":{
                "iataCode":"ORY",
                "icaoCode":"LFPO"
              },
              "aircraft":{
                "regNumber":"FGZHS",
                "icaoCode":"B738",
                "icao24":"3964F2",
                "iataCode":"B738"
              },
              "airline":{
                "iataCode":"TO",
                "icaoCode":"TVF"
              },
              "flight":{
                "iataNumber":"TO3875",
                "icaoNumber":"TVF3875",
                "number":"3875"
              },
              "system":{
                "updated":"1543087861",
                "squawk":"7376"
              },
              "status":"started"
            }
          ]
        }
        

        Would obj.aircraft[0].geography
        not be an object ? with keys latitude,longitude etc ?

        1 Reply Last reply
        0
        • F filipdns

          @Christian-Ehrlicher I try to work with it like array:

          var obj =JSON.parse(res)
          console.log(obj.aircraft[0].geography)

          but the return message is [object Object]...

          kshegunovK Offline
          kshegunovK Offline
          kshegunov
          Moderators
          wrote on last edited by
          #13

          Firstly, what is this language? JS?
          Secondly, what is JSON in your code and where does it come from?

          Read and abide by the Qt Code of Conduct

          F 1 Reply Last reply
          0
          • kshegunovK kshegunov

            Firstly, what is this language? JS?
            Secondly, what is JSON in your code and where does it come from?

            F Offline
            F Offline
            filipdns
            wrote on last edited by
            #14

            @kshegunov Hello,

            Yes, it's JS language to get the network response.

            the JSON response is come from http://aviation-edge.com

            with request like http://aviation-edge.com/v2/public/flights?key=2a8619-db5a5c&regNum=ECMJT

            kshegunovK 1 Reply Last reply
            0
            • F filipdns

              @kshegunov Hello,

              Yes, it's JS language to get the network response.

              the JSON response is come from http://aviation-edge.com

              with request like http://aviation-edge.com/v2/public/flights?key=2a8619-db5a5c&regNum=ECMJT

              kshegunovK Offline
              kshegunovK Offline
              kshegunov
              Moderators
              wrote on last edited by
              #15

              I am now completely confused. How and why is this JS executed and what relation does it bear to Qt? Is this a QML function?

              Read and abide by the Qt Code of Conduct

              F 1 Reply Last reply
              0
              • kshegunovK kshegunov

                I am now completely confused. How and why is this JS executed and what relation does it bear to Qt? Is this a QML function?

                F Offline
                F Offline
                filipdns
                wrote on last edited by
                #16

                @kshegunov Hi, it has no link with qt, it's just in case some one can help me to parse JSON with keys.

                But did what I need parsing in JS but it's not very beautiful code like it is example:

                                res=doc.responseText//JS.data(doc.responseText)
                                //console.log(res)
                                //var obj =JSON.parse(res)
                                var error="{\"error\": \"No Record Found or Flight not currently detected by receivers. \" }"
                                if(res!==error)
                                {
                                    var res1=res.replace("[","")
                                    var res2=res1.replace("{","")
                                    var res3=res2.split("{")
                                    var res4=res3[1]
                                    var res5= res4.split(",")
                                    var res6=res5[0]+res5[1]+res5[2]+res5[3]
                                    var res7=res6
                                    var res8=res7.replace("\n","")
                                    var res9=res8.replace("            ","")
                                    var res10=res9.replace("\"","")
                                    var res11=res10.split(":")
                                    var res12=res11[0].replace("\"","") //text: latitude
                                    var res13=res11[1].split("\n")
                                    var res14=parseFloat(res13[0])      //valeur latitude
                                    var res15=res13[1].replace("            \"","")
                                    var res16=res15.replace("\"","")    //text longitude
                                    var res17=parseFloat(res11[2].split("\n")[0])// valeur longitude
                                    var res18=parseInt(parseFloat(res11[3].split("\n")[0])*3.28084/100) // valeur altitude
                                    var res19 = parseInt(res11[4].split("\n")[0]) // valeur cap
                
                1 Reply Last reply
                0
                • F filipdns

                  Hello,

                  I'm trying to parse value from JSON file:

                  [ { "geography": { "latitude": 51.1392, "longitude": 11.1481, "altitude": 11280.5, "direction": 68.9 }, "speed": { "horizontal": 805.37, "isGround": 0, "vertical": -3.90144 }, "departure": { "iataCode": "BVA", "icaoCode": "LFOB" }, "arrival": { "iataCode": "CIA", "icaoCode": "LIRA" }, "aircraft": { "regNumber": "EIGDT", "icaoCode": "B738", "icao24": "", "iataCode": "B738" }, "airline": { "iataCode": "FR", "icaoCode": "RYR" }, "flight": { "iataNumber": "FR92QB", "icaoNumber": "RYR92QB", "number": "92QB" }, "system": { "updated": "1543065538", "squawk": "1127" }, "status": "en-route" }, { "geography": { "latitude": 43.4357, "longitude": 18.9397, "altitude": 11280.5, "direction": 136 }, "speed": { "horizontal": 914.949, "isGround": 0, "vertical": -5.20192 }, "departure": { "iataCode": "BVA", "icaoCode": "LFOB" }, "arrival": { "iataCode": "SKG", "icaoCode": "LGTS" }, "aircraft": { "regNumber": "EIEKI", "icaoCode": "B738", "icao24": "4CA808", "iataCode": "B738" }, "airline": { "iataCode": "FR", "icaoCode": "RYR" }, "flight": { "iataNumber": "FR3094", "icaoNumber": "RYR3094", "number": "3094" }, "system": { "updated": "1543065479", "squawk": "664" }, "status": "en-route" } ]
                  

                  with

                  
                     QByteArray data= reply->readAll();
                     QString datastring = QString::fromStdString(data.toStdString());
                      //qDebug()<<data;
                  
                      bool ok;
                      // datastring is a QString containing the JSON data
                      QtJson::JsonObject result = QtJson::parse(datastring, ok).toMap();
                  
                      if(!ok) {
                        qFatal("An error occurred during parsing");
                      }
                  
                      qDebug() << "latitude:" << result["latitude"].toString();
                  

                  but the result say only:

                  latitude: ""

                  What I did wrong?

                  [Moved to General and Desktop ~kshegunov]

                  Taz742T Offline
                  Taz742T Offline
                  Taz742
                  wrote on last edited by
                  #17

                  @filipdns
                  It is not a valid json file. https://forum.qt.io/topic/64314/json-access-data-in-multidimensional-arrays/8

                  Do what you want.

                  F 1 Reply Last reply
                  3
                  • Taz742T Taz742

                    @filipdns
                    It is not a valid json file. https://forum.qt.io/topic/64314/json-access-data-in-multidimensional-arrays/8

                    F Offline
                    F Offline
                    filipdns
                    wrote on last edited by
                    #18

                    @Taz742 thank you, I will stay with my poor code then lol

                    aha_1980A 1 Reply Last reply
                    0
                    • F filipdns

                      @Taz742 thank you, I will stay with my poor code then lol

                      aha_1980A Offline
                      aha_1980A Offline
                      aha_1980
                      Lifetime Qt Champion
                      wrote on last edited by
                      #19

                      @filipdns

                      Did you read the post @Taz742 linked?

                      Your top-level structure is a JSON array, so you must convert the document to a QJsonArray, not a QJsonObject.

                      Using a QJsonArray should work for you, too.

                      Qt has to stay free or it will die.

                      F 1 Reply Last reply
                      1
                      • aha_1980A aha_1980

                        @filipdns

                        Did you read the post @Taz742 linked?

                        Your top-level structure is a JSON array, so you must convert the document to a QJsonArray, not a QJsonObject.

                        Using a QJsonArray should work for you, too.

                        F Offline
                        F Offline
                        filipdns
                        wrote on last edited by filipdns
                        #20

                        @aha_1980 Hello, I start to read yes, I'm trying to understand how do that in js, I found documentation on QJsonArray only for c++ at the moment

                        kshegunovK 1 Reply Last reply
                        0
                        • F filipdns

                          @aha_1980 Hello, I start to read yes, I'm trying to understand how do that in js, I found documentation on QJsonArray only for c++ at the moment

                          kshegunovK Offline
                          kshegunovK Offline
                          kshegunov
                          Moderators
                          wrote on last edited by kshegunov
                          #21

                          In JS you just parse it, as it's a natively supported.

                          var myJson = JSON.eval(jsonText);
                          

                          If it's a valid json, then properties are available directly as any other java script object, or in your case:

                          var obj =JSON.parse(res);
                          console.log("Latitude: " + obj.aircraft[0].geography.latitude);
                          

                          I still don't get the relevance, though.

                          Read and abide by the Qt Code of Conduct

                          1 Reply Last reply
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                          • M Offline
                            M Offline
                            makcorps
                            Banned
                            wrote on last edited by
                            #22
                            This post is deleted!
                            1 Reply Last reply
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