Change colour from bool within array in QML

Question

I am looking to change the colour of a Calendar cell from a Boolean within an array (calendarListModel).

Here's a sample of the array:

[
{"date":1544443200000,"name":"Edward","status":1},
{"date":1544529600000,"name":"Katie","status":0},
{"date":1544616000000,"name":"Claire","status":1}
]

What I want to do is change the colour of my calendar marker depending on the Boolean value within calendarListModel ("status": 0 or 1).

The code for my marker is;

Rectangle {
    id: calendarMarker
    visible: arrayFromFireBase.indexOf(styleData.date.getTime()) > -1
    anchors.fill: parent
    color:  "blue"
} 

I have tried making changes to the colour of the Rectangle with things such as calendarListModel.status ? "blue" : "red" amongst other variations but am either getting each cell as blue or red, or none at all?

Question: What would be the best way to change the colour based on a true/false value from the array?

I am using Calendar from the QtQuick.Controls to display dates and CalendarStyle from QtQuick.Controls.Styles to assign a custom style. I'm also using the V-Play sdk.

Here's a minimal, complete, and verifiable example of what I'm currently doing:

import VPlayApps 1.0
import QtQuick 2.2
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.1

App {
    id: app

    //  this model is read from a firebase db using v-play
    property var calendarListModel: [
        {"date":1544443200000,"name":"Edward","status":1},
        {"date":1544529600000,"name":"Katie","status":0},
        {"date":1547182800000,"name":"Claire","status":1}
    ]

    Calendar {
        id: calendar
        anchors.fill: parent
        selectedDate: new Date()
        weekNumbersVisible: true
        focus: true
        onSelectedDateChanged: {
            const day = selectedDate.getDate();
            const month = selectedDate.getMonth() + 1;
            const year = selectedDate.getFullYear();
        }

       style: CalendarStyle {
           dayOfWeekDelegate: Item {
               width: parent.width
               height: dp(30)
               Rectangle {
                   anchors.fill: parent
                   border.color: "#00000000"
                   Label {
                       id: dayOfWeekDelegateText
                       text: Qt.locale().dayName(styleData.dayOfWeek, Locale.ShortFormat)
                       anchors.centerIn: parent
                       color: "black"
                   }
               }
           }

           //  a delegate for each day cell
           dayDelegate: Item {
               id: container

               readonly property color sameMonthDateTextColor: "#444"
               readonly property color selectedDateColor: "#20d5f0"
               readonly property color selectedDateTextColor: "white"
               readonly property color differentMonthDateTextColor: "#bbb"

               //  the background of each cell
               Rectangle {
                   anchors.fill: parent
                   border.color: "#00000000"
                   color: styleData.selected ? selectedDateColor : "white"
               }

               //  a marker on the upper-left corner on each cell
               Rectangle {
                   id: calendarMarker
                   property bool isConfirmed: false
                   anchors {
                       top: parent.top; left: parent.left
                   }

                   width: 12
                   height: width

                   //  the issue lies here
                   color: {
                        var confCol
                        calendarListModel.indexOf(status? true : false)
                        confCol ? "#4286f4" : "red"
                   }

               }

               // the day number
               Label {
                   id: dayDelegateText
                   text: styleData.date.getDate()
                   anchors.centerIn: parent
                   color:  styleData.selected ? selectedDateTextColor : styleData.visibleMonth ? sameMonthDateTextColor : differentMonthDateTextColor
               }
            }
        }
    }
}

Answer 1

Alright, right now you're using an array of objects and trying to index it directly, which is no good. (Especially since you're currently indexing for true/false values, which doesn't comprise individual elements in calendarListModel.) Even if you could reconstruct the object with a date, name, and status, they'll still be different objects.

Use Array.prototype.find() instead.

color: {
    var modelObject = calendarListModel.find(
       function(obj) {
            //  look for a matching date
           return obj.date === styleData.date.getTime();
       }
    );

    if (modelObject === undefined)  //  not found in list model
       return "lightgrey";

    return modelObject.status ? "blue" : "red";
}

Here's a before and after tested from a macOS:

Before: Notice how all markers are red. Only the dates specified in calendarListModel should have colour to them.

After: Notice that only the marker at January 11 has colour (blue). Indeed, this is because the date was included in calendarListModel: 1544616000000.