Question

i having a problem with a global method called returnDayNumber. If i call the function within my java script it works fine. but when i made a button to call the function it said: “self.returnDayNumber is not a function” (thought var self=this might solve issue).
here is my code:

 /*
     * Global data
     * used to centralize user data to be used in graphs
     */
    var userModel = new userHealthModel();
    userModel.createUsers();

    userModel.addUser();


    var newChart = new NewHighCharts();

    returnDayNumber = function(month, day)
    {
        if(month==1)
        {
            return day;
        }
        else if(month==2)
        {
            return(31+day);
        }
        else if(month==3)
        {
            return(60+day);
        }
        else if(month==4)
        {
            return (91+day);
        }
        else if(month==5)
        {
            return(121+day);
        }
        else if(month==6)
        {
            return(152+day);
        }
        else if(month==7)
        {
            return(182+day);
        }
        else if(month==8)
        {
            return(213+day);
        }
        else if(month==9)
        {
            return(244+day);
        }
        else if(month==10)
        {
            return(274+day);
        }
        else if(month==11)
        {
            return(305+day);
        }
        else if(month==12)
        {
            return(335+day);
        }           
    }
    saveThis = function()
    {
        var self = this;
        alert("your about to save!")
        newChart.destroyChart();
        newChart= new NewHighCharts();
        var numberOfUsers = userModel.users().length;
        var users = userModel.users();
        var weights = userModel.getWeights();
        var dates = userModel.getDates();
        var dataArray = [];
        var xAndY = []
        var singleDate;
        var name;
        for(var i=0;i<numberOfUsers;i++)
        {
            name = users[i].name;
            xAndY = [];
            for(var x=0;x<dates.length-1;x++)
            {

                //extract month
                var month = ([dates[i][x]].toString()).substring(0,2);
                //extract day
                day = parseInt(([dates[i][x]].toString()).substring(3,5));
                //add the day number and weight of users to an array of x and y coordinates
                xAndY.push([self.returnDayNumber(month,day),weights[i][x]])
            }
            newChart.addNewSeries(name,xAndY);
        }       
     ///!!!!This works!!!///
     this.saveThis()//!!!

    }
    ko.applyBindings(userModel);

i made a KO user model but i dont think its relevant. and here is my HTML, note its KO syntax but it works.

<button  data-bind="click: saveThis">Save</button>

im probably making a simple mistake or something is out of scope. Im a java script beginner so sorry for the simple question. Many thanks to any helpful programmers!

Answer 1

Move var self = this; outside of your saveThis function not inside, that way self is in the right scope.