how to pass dynamic column names to observable array

Question

For example if my loop is as below

function test(obsArray,dynamicColumnName){
     var item = obsArray();
    ko.utils.arrayForEach(item, function(data) {
                computedColName = ko.computed(function () {
                    return data.dynamicColumnName();

    });
}

How do i pass dynamic columns in loop of array?

I tried the above approach but i get error as Object doesnt support property or method dynamicColumnName

Please post the full code. what is item? is it an array? does the array item have an observable called dynamicColumnName? — Sherin Mathew, Jun 18 '14 at 05:07
@SherinMathew item is an array. the observable doesnt have property called dynamicColumnName but i am passing valid property via that parameter in function test — James, Jun 18 '14 at 05:09
If the array item doesn't have a property, how can you call it like this - data.dynamicColumnName()? What are you trying to achieve? — Sherin Mathew, Jun 18 '14 at 05:12
possible duplicate of [JavaScript object: access variable property by name as string](http://stackoverflow.com/questions/4255472/javascript-object-access-variable-property-by-name-as-string)... javascript 101. — Jeff Mercado, Jun 18 '14 at 05:22
@JeffMercado so can i write like data.[dynamicColumnName]() ? can you tell exactly how to write it? — James, Jun 18 '14 at 05:41
Assuming `dynamicColumnName` is a string or other appropriate type, then yes most likely. **Try it.** — Jeff Mercado, Jun 18 '14 at 05:42
you are getting this error because `dynamicColumnName()` is not observable — Muhammad Raheel, Jun 18 '14 at 06:42
@jeffMercado i tried like data.[dynamiccolumnname]() but it gives me syntax error identifier expected — James, Jun 18 '14 at 07:00
@RaheelShan yes dynamicColumn is not observable but i want to access it as property of array — James, Jun 18 '14 at 07:02

score 0 · Answer 1 · answered Jun 18 '14 at 07:08

I assunme you want to add computed to each object of array. Each computed should be dependant of name property.

var arr = [
    {name:"A",active:true},
    {name:"B",active:true},
    {name:"C",active:true},
]

function test(){
    var self = this

    self.TestData = ko.observableArray([])

    self.LoadData = function(){
        self.TestData(arr)
        self.MakeComputed()
    }

    self.MakeComputed = function(){
        ko.utils.arrayForEach(self.TestData(),function(data) {
            data.computedColName = ko.computed(function () {
                return data.dynamicColumnName();
            });
        });     
    }
    self.LoadData()
}

ko.applyBindings(new test())

how to pass dynamic column names to observable array

1 Answers1