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bug in a JS function

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  • JKSHJ JKSH

    @mzimmers It's not clear from your snippets:

    • Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?
    • Where is `unassignedValves defined? What does it contain?
    • What is the definition of ValveConfigurationList?
    mzimmersM Offline
    mzimmersM Offline
    mzimmers
    wrote on last edited by
    #8

    @JKSH said in bug in a JS function:

    @mzimmers It's not clear from your snippets:

    • Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

    No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

    • Where is `unassignedValves defined? What does it contain?

    In EquipmentConfigEdit.qml (I forgot to qualify that one; now fixed). Here's the definition:

    property var unassignedValves: outcomeModel.unassignedValves() 
    
    • What is the definition of ValveConfigurationList?
    #define ValveConfigurationList QList<QUuid>
    class Outcome: public QObject
    {
        Q_OBJECT
        QML_ELEMENT
        Q_PROPERTY(ValveConfigurationList valveConfigurationList READ valveConfigurationList WRITE setValveConfigurationList NOTIFY valveConfigurationListChanged FINAL)
        ValveConfigurationList valveConfigurationList() { return m_valveConfigurationList; }
        bool setValveConfigurationList(const ValveConfigurationList &list);
    
    JKSHJ 1 Reply Last reply
    0
    • mzimmersM mzimmers

      @JKSH said in bug in a JS function:

      @mzimmers It's not clear from your snippets:

      • Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

      No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

      • Where is `unassignedValves defined? What does it contain?

      In EquipmentConfigEdit.qml (I forgot to qualify that one; now fixed). Here's the definition:

      property var unassignedValves: outcomeModel.unassignedValves() 
      
      • What is the definition of ValveConfigurationList?
      #define ValveConfigurationList QList<QUuid>
      class Outcome: public QObject
      {
          Q_OBJECT
          QML_ELEMENT
          Q_PROPERTY(ValveConfigurationList valveConfigurationList READ valveConfigurationList WRITE setValveConfigurationList NOTIFY valveConfigurationListChanged FINAL)
          ValveConfigurationList valveConfigurationList() { return m_valveConfigurationList; }
          bool setValveConfigurationList(const ValveConfigurationList &list);
      
      JKSHJ Offline
      JKSHJ Offline
      JKSH
      Moderators
      wrote on last edited by
      #9

      @mzimmers said in bug in a JS function:

      #define ValveConfigurationList QList<QUuid>
      class Outcome: public QObject
      {
          Q_OBJECT
          QML_ELEMENT
          Q_PROPERTY(ValveConfigurationList valveConfigurationList READ valveConfigurationList WRITE setValveConfigurationList NOTIFY valveConfigurationListChanged FINAL)
          ValveConfigurationList valveConfigurationList() { return m_valveConfigurationList; }
          bool setValveConfigurationList(const ValveConfigurationList &list);
      

      Hmm... I'm not sure if the #define will play nicely with Qt's property system. https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-properties says "Do not use typedef or using for Q_PROPERTY types as these will confuse moc). I'd imagine that the same goes for #define.

      As a sanity check, put qDebug() << list; inside setValveConfigurationList(). Is your C++ function receiving the expected list?

      Try replacing ValveConfigurationList with QList<QUuid> throughout your header. Does that make a difference? (If not, your best bet for quick troubleshooting is to provide a minimal, compilable example that triggers the issue)

      • Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

      No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

      OK. And does VspEdit contain required property EquipmentConfigEdit equipmentEdit or similar? (Remember, use EquipmentConfigEdit instead of var)

      • Where is `unassignedValves defined? What does it contain?

      In EquipmentConfigEdit.qml (I forgot to qualify that one; now fixed). Here's the definition:

      property var unassignedValves: outcomeModel.unassignedValves() 
      

      I don't think this is related to your issue, but do you need a separate property called EquipmentConfigEdit.unassignedValves? Could you just do let newValveUuid = equipmentEdit.outcomeModel.unassignedValves[i] or similar?

      Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

      mzimmersM 1 Reply Last reply
      0
      • JKSHJ JKSH

        @mzimmers said in bug in a JS function:

        #define ValveConfigurationList QList<QUuid>
        class Outcome: public QObject
        {
            Q_OBJECT
            QML_ELEMENT
            Q_PROPERTY(ValveConfigurationList valveConfigurationList READ valveConfigurationList WRITE setValveConfigurationList NOTIFY valveConfigurationListChanged FINAL)
            ValveConfigurationList valveConfigurationList() { return m_valveConfigurationList; }
            bool setValveConfigurationList(const ValveConfigurationList &list);
        

        Hmm... I'm not sure if the #define will play nicely with Qt's property system. https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-properties says "Do not use typedef or using for Q_PROPERTY types as these will confuse moc). I'd imagine that the same goes for #define.

        As a sanity check, put qDebug() << list; inside setValveConfigurationList(). Is your C++ function receiving the expected list?

        Try replacing ValveConfigurationList with QList<QUuid> throughout your header. Does that make a difference? (If not, your best bet for quick troubleshooting is to provide a minimal, compilable example that triggers the issue)

        • Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

        No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

        OK. And does VspEdit contain required property EquipmentConfigEdit equipmentEdit or similar? (Remember, use EquipmentConfigEdit instead of var)

        • Where is `unassignedValves defined? What does it contain?

        In EquipmentConfigEdit.qml (I forgot to qualify that one; now fixed). Here's the definition:

        property var unassignedValves: outcomeModel.unassignedValves() 
        

        I don't think this is related to your issue, but do you need a separate property called EquipmentConfigEdit.unassignedValves? Could you just do let newValveUuid = equipmentEdit.outcomeModel.unassignedValves[i] or similar?

        mzimmersM Offline
        mzimmersM Offline
        mzimmers
        wrote on last edited by
        #10

        @JKSH said in bug in a JS function:

        Hmm... I'm not sure if the #define will play nicely with Qt's property system. https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-properties says "Do not use typedef or using for Q_PROPERTY types as these will confuse moc). I'd imagine that the same goes for #define.
        As a sanity check, put qDebug() << list; inside setValveConfigurationList(). Is your C++ function receiving the expected list?

        I stepped into it in the debugger; it seems to be getting the correct list.

        Try replacing ValveConfigurationList with QList<QUuid> throughout your header. Does that make a difference? (If not, your best bet for quick troubleshooting is to provide a minimal, compilable example that triggers the issue)

        No, it doesn't.

        Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

        No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

        OK. And does VspEdit contain required property EquipmentConfigEdit equipmentEdit or similar? (Remember, use EquipmentConfigEdit instead of var)

        No. VspEdit is used within EquipmentConfigEdit.qml as folllows:

        ListView {
            model: equipmentCopy
            delegate: DelegateChooser {
                role: "category"
                DelegateChoice {
                    roleValue: NgaUI.CATEGORY_VSP
                    delegate: VspEdit {
                        equipment: equipmentEdit.equipment
                        equipmentCopy: equipmentEdit.equipmentCopy
        

        equipmentEdit is the id assigned to EquipmentConfigEdit.qml.

        Where is `unassignedValves defined? What does it contain?
        Also in EquipmentConfigEdit.qml:

        property var unassignedValves: outcomeModel.unassignedValves()
        

        I don't think this is related to your issue, but do you need a separate property called EquipmentConfigEdit.unassignedValves? Could you just do let newValveUuid = equipmentEdit.outcomeModel.unassignedValves[i] or similar?

        I did this (no change in results):

        var newValveUuid = outcomeModel.unassignedValves()[i]
        

        I will work on a minimal example. Thanks for the help.

        mzimmersM 1 Reply Last reply
        0
        • mzimmersM mzimmers

          @JKSH said in bug in a JS function:

          Hmm... I'm not sure if the #define will play nicely with Qt's property system. https://doc.qt.io/qt-6/qtqml-cppintegration-exposecppattributes.html#exposing-properties says "Do not use typedef or using for Q_PROPERTY types as these will confuse moc). I'd imagine that the same goes for #define.
          As a sanity check, put qDebug() << list; inside setValveConfigurationList(). Is your C++ function receiving the expected list?

          I stepped into it in the debugger; it seems to be getting the correct list.

          Try replacing ValveConfigurationList with QList<QUuid> throughout your header. Does that make a difference? (If not, your best bet for quick troubleshooting is to provide a minimal, compilable example that triggers the issue)

          No, it doesn't.

          Where is replaceValve() defined? Is it inside EquipmentConfigEdit.qml?

          No, it's in another QML file. EquipmentConfigEdit.qml has a DelegateChoice that uses VspEdit.qml, which uses another file with the above script.

          OK. And does VspEdit contain required property EquipmentConfigEdit equipmentEdit or similar? (Remember, use EquipmentConfigEdit instead of var)

          No. VspEdit is used within EquipmentConfigEdit.qml as folllows:

          ListView {
              model: equipmentCopy
              delegate: DelegateChooser {
                  role: "category"
                  DelegateChoice {
                      roleValue: NgaUI.CATEGORY_VSP
                      delegate: VspEdit {
                          equipment: equipmentEdit.equipment
                          equipmentCopy: equipmentEdit.equipmentCopy
          

          equipmentEdit is the id assigned to EquipmentConfigEdit.qml.

          Where is `unassignedValves defined? What does it contain?
          Also in EquipmentConfigEdit.qml:

          property var unassignedValves: outcomeModel.unassignedValves()
          

          I don't think this is related to your issue, but do you need a separate property called EquipmentConfigEdit.unassignedValves? Could you just do let newValveUuid = equipmentEdit.outcomeModel.unassignedValves[i] or similar?

          I did this (no change in results):

          var newValveUuid = outcomeModel.unassignedValves()[i]
          

          I will work on a minimal example. Thanks for the help.

          mzimmersM Offline
          mzimmersM Offline
          mzimmers
          wrote on last edited by
          #11

          First attempt at a minimal example produced a working script (crud).

          I'm 99% sure that I'm successfully accessing the variables created in the file EquipmentConfigEdit.qml. Now, with the fully qualified variable names, I'm getting the same error, but on "equipmentEdit."

          assignedValves[indexToReplace] = newValveUuid
          console.log("EquipmentSelectValves.qml.replaceValve(): assignedValves (after) is " + assignedValves)
          
          equipmentEdit.outcome.valveConfigurationList = assignedValves
          // line 197 below.
          console.log("EquipmentSelectValves.qml.replaceValve(): equipmentEdit.outcome.valveConfigurationList is " + equipmentEdit.outcome.valveConfigurationList)
          

          produces this error:

          qrc:/qt/qml/NgaIcdFw/qml/equipment/EquipmentSelectValves.qml:197: ReferenceError: equipmentEdit is not defined
          

          if I comment out that log, the next variable I hit is said to be not defined.

          It's really like the call to setValveConfigurationList() is somehow clobbering something in my script.

          mzimmersM 1 Reply Last reply
          0
          • mzimmersM mzimmers

            First attempt at a minimal example produced a working script (crud).

            I'm 99% sure that I'm successfully accessing the variables created in the file EquipmentConfigEdit.qml. Now, with the fully qualified variable names, I'm getting the same error, but on "equipmentEdit."

            assignedValves[indexToReplace] = newValveUuid
            console.log("EquipmentSelectValves.qml.replaceValve(): assignedValves (after) is " + assignedValves)
            
            equipmentEdit.outcome.valveConfigurationList = assignedValves
            // line 197 below.
            console.log("EquipmentSelectValves.qml.replaceValve(): equipmentEdit.outcome.valveConfigurationList is " + equipmentEdit.outcome.valveConfigurationList)
            

            produces this error:

            qrc:/qt/qml/NgaIcdFw/qml/equipment/EquipmentSelectValves.qml:197: ReferenceError: equipmentEdit is not defined
            

            if I comment out that log, the next variable I hit is said to be not defined.

            It's really like the call to setValveConfigurationList() is somehow clobbering something in my script.

            mzimmersM Offline
            mzimmersM Offline
            mzimmers
            wrote on last edited by
            #12

            @JKSH I have a minimal example now. I've zipped it up. Where would you like me to put it?

            JKSHJ 1 Reply Last reply
            0
            • mzimmersM mzimmers

              @JKSH I have a minimal example now. I've zipped it up. Where would you like me to put it?

              JKSHJ Offline
              JKSHJ Offline
              JKSH
              Moderators
              wrote on last edited by
              #13

              @mzimmers said in bug in a JS function:

              @JKSH I have a minimal example now. I've zipped it up. Where would you like me to put it?

              Any file sharing service of your choice should be fine (Dropbox, Google Drive, Microsoft OneDrive, etc.) Or you could push it to a public Git host (e.g. GitHub, Atlassian Bitbucket, etc.)

              Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

              mzimmersM 1 Reply Last reply
              0
              • JKSHJ JKSH

                @mzimmers said in bug in a JS function:

                @JKSH I have a minimal example now. I've zipped it up. Where would you like me to put it?

                Any file sharing service of your choice should be fine (Dropbox, Google Drive, Microsoft OneDrive, etc.) Or you could push it to a public Git host (e.g. GitHub, Atlassian Bitbucket, etc.)

                mzimmersM Offline
                mzimmersM Offline
                mzimmers
                wrote on last edited by
                #14

                @JKSH Here it is:

                my zip zile

                If you can figure out what's going on with this, I'll buy you a seafood dinner the next time you're in Monterey.

                1 Reply Last reply
                0
                • JKSHJ Offline
                  JKSHJ Offline
                  JKSH
                  Moderators
                  wrote on last edited by
                  #15

                  Looks like you've found an interesting bug related to Components accessing external IDs.

                  Add pragma ComponentBehavior: Bound to the top of EquipmentSelectValves.qml (see https://doc.qt.io/qt-6/qtqml-documents-structure.html#componentbehavior ). This makes the QML engine a bit stricter though, so you need to also mark your delegate's modelData and index properties as required property (see the examples at https://doc.qt.io/qt-6/qtquick-modelviewsdata-modelview.html#models ). This is not necessarily a bad thing, as it enforces good practice.

                  Note: After this, your example will no longer complain that outcome is not defined, but it will complain about equipmentModel because that is truly not defined anywhere in your example.

                  Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                  mzimmersM 1 Reply Last reply
                  1
                  • JKSHJ JKSH

                    Looks like you've found an interesting bug related to Components accessing external IDs.

                    Add pragma ComponentBehavior: Bound to the top of EquipmentSelectValves.qml (see https://doc.qt.io/qt-6/qtqml-documents-structure.html#componentbehavior ). This makes the QML engine a bit stricter though, so you need to also mark your delegate's modelData and index properties as required property (see the examples at https://doc.qt.io/qt-6/qtquick-modelviewsdata-modelview.html#models ). This is not necessarily a bad thing, as it enforces good practice.

                    Note: After this, your example will no longer complain that outcome is not defined, but it will complain about equipmentModel because that is truly not defined anywhere in your example.

                    mzimmersM Offline
                    mzimmersM Offline
                    mzimmers
                    wrote on last edited by mzimmers
                    #16

                    @JKSH said in bug in a JS function:

                    Looks like you've found an interesting bug related to Components accessing external IDs.

                    I love when things aren't (entirely) my fault.

                    Add pragma ComponentBehavior: Bound to the top of EquipmentSelectValves.qml
                    you need to also mark your delegate's modelData and index properties as required property

                    Done and done.

                    it will complain about equipmentModel because that is truly not defined anywhere in your example.

                    Yeah, I forgot to remove that part (because it bombed before it got there). Shouldn't be a problem in my real app, where I have this line in main.cpp:

                        engine.rootContext()->setContextProperty("equipmentModel", equipmentModel);
                    

                    Let me know when you're in town, and I'll buy you the best dinner Monterey can offer (which is pretty damn good, IMO).

                    Should I report this bug, and if so, how should I characterize it?

                    1 Reply Last reply
                    0
                    • mzimmersM mzimmers has marked this topic as solved on
                    • JKSHJ Offline
                      JKSHJ Offline
                      JKSH
                      Moderators
                      wrote on last edited by JKSH
                      #17

                      Actually, I don't think it's a bug after all. Basically:

                      1. Your replaceValve() function is a "member" of your delegate. (More precisely, replaceValve() exists within the context of your valveBox delegate, which is separate from the context of EquipmentSelectValves by default)
                      2. That function modifies the ListView's model.
                      3. Modifying the model caused your delegate (and its context) to be destroyed.
                      4. Destroying the delegate's context invalidates the references inside replaceValve().

                      Here is a minimal reproducer for your issue:

                      //pragma ComponentBehavior: Bound
                      import QtQuick
                      import QtQuick.Controls.Basic
                      
                      Window {
                          width: 800
                          height: 600
                          visible: true
                      
                          ListView {
                              id: lv
                              anchors.fill: parent
                              model: 1
                              delegate: Button {
                                  text: "Click me"
                      
                                  onClicked: {
                                      console.log("parent: " + parent)
                                      console.log("lv: " + lv)
                                      lv.model = 0
                                      console.log("parent: " + parent)
                                      console.log("lv: " + lv)
                                  }
                      
                                  Component.onDestruction: console.log("Destroyed", this)
                              }
                          }
                      }
                      
                      

                      Output:

                      qml: parent: QQuickItem(0x1257086c4a0)
                      qml: lv: QQuickListView(0x12570653350)
                      qml: Destroyed Button_QMLTYPE_1(0x12570653b30)
                      qml: parent: null
                      Main.qml:22: ReferenceError: lv is not defined
                      

                      pragma ComponentBehavior: Bound changes QML's behaviour and puts replaceValve() inside the same context as EquipmentSelectValves, so you get the outcome that you expect. Qt can't make
                      this the default yet because it will break old user code. But https://doc.qt.io/qt-6/qtqml-documents-structure.html#componentbehavior does say "The default value of ComponentBehavior is Unbound.... In a future version of Qt the default will change to Bound."

                      I haven't visited Monterey before, but I'll give you a buzz if I'm ever in town. That seafood sounds tempting ;-)

                      Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                      1 Reply Last reply
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