I'm having trouble with my observable array not updating. Can someone help me figure out what I'm

function AppViewModel() {
self.tagbuttons=ko.observableArray([
    {shotbar:false, frozendrinks: false, livemusic: false, patio:false, food:false}
    ]);

self.toggleTag = function(data,event) {
    var id = event.target.id;

    self.tagbuttons()[0][id] = !self.tagbuttons()[0][id];
    console.log(self.tagbuttons()[0][id]);
    if(self.tagbuttons()[0][id] == true)
    {
        $(event.target).closest('li').addClass("active");
        console.log(event.target.id+":"+"active");
    }
    else
    {
        $(event.target).closest('li').removeClass("active");
        console.log(event.target.id+":"+"inactive");}
    }
}

ko.applyBindings(new AppViewModel());

The output of my console.log(self.tagbuttons()[0][id]) correctly displays the boolean value, but the value does not update in my array. Here is the HTML code:

 <div data-bind="text: tagbuttons()[0].shotbar"></di>

Answer №1

It's crucial to remember that you must apply the KO bindings once you have declared your MyAppViewModel and after the UI has been loaded:

$(document).ready(function(){
    ko.ApplyBindings(new MyAppViewModel());
});

If you fail to apply the KO bindings, nothing will occur beyond the boundaries of the view model.

Answer №2

Here's an excerpt from the ko documentation that highlights a key concept:

Main idea: An observableArray keeps track of which objects are in the array, not their individual state

Merely inserting an object into an observableArray does not automatically make all of its properties observable. You have the option to make these properties observable separately. The main function of an observableArray is to monitor the objects it contains and signal listeners when objects are added or removed.

Therefore, modifying the value of an item within the array will not trigger knockout notifications. To manually notify subscribers, you can utilize the valueHasMutated function like so:

self.tagbuttons()[0][id] = !self.tagbuttons()[0][id];
self.tagbuttons.valueHasMutated();

Alternatively, you can encase items in the array with observable:

self.tagbuttons = ko.observableArray([
ko.observable({
    shotbar:false, 
    frozendrinks: false, 
    livemusic: false, 
    patio:false, 
    food:false})
    ]);

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