computed-observable

I'm faced a problem that my computed observable stops triggering after some sequence of dependency changes. Finally I found out the point: if dependency was inside of false branch statement during latest evaluation, computed will not be triggered next time even if condition became true before evaluation finished . Here is a sample: https://jsfiddle.net/sgs218w0/1/ var viewModel = new function(){ var self = this; self.trigger = ko.observable(true); self.fire = function(){ self.trigger(! self.trigger()); }; self.content = function(){ var test = 3; return ko.computed(function(){ alert("triggered!

Given a computed property vm.checkedValueCount = ko.computed(function(){ var observables = getCurrentValues(); //an array of ko.observable[] return _.filter(observables, function(v) { return v() }).length; }); suppose getCurrentValues() can return different sets of observables which are modified elsewhere in the code (and comes from a more complex structure than an observableArray). I need checkedValueCount to update whenever one of its dependencies change getCurrentValues() returns a different set of observables. The problem is that ko.computed seems to memoize the last returned value and

Situation: kendo DataSource var ordersDataSource = new kendo.data.DataSource({ type: "odata", transport: { read: { url: "http://localhost/odata.svc/Orders?$expand=OrderDetails" } }, schema: { type: "json", data: function(response){ return response.value; } total: function(response){ return response['odata.count']; } }, serverPaging: true, serverFiltering: true, serverSorting: true }) the json data read from the odata source is like: { odata.metadata: "xxxx", odata.count: "5", value: [ { OrderId: 1, OrderedDate: "2013-02-20", OrderInfoA: "Info A", OrderInfoB: "Info B" OrderDetails: [ {

I would like to know how to create a computed observable array. In my view model, I have 2 observable arrays, and I would like to have a computed observable array that is simply both arrays combined. function ViewModel() { var self = this; self.listA= ko.observableArray([]); self.listB = ko.observableArray([]); self.masterList= //combine both list A and B This will combine the two arrays and return the combined list. However, it is not a computed observable array (don't know if that is even possible), but a regular computed observable. self.masterList = ko.computed(function() { return this

When using knockout, what is the advantage of using read-only computed observables rather than simple functions? Take the following viewmodel constructor and html snippet, for example: ​ var ViewModel = function(){ var self = this; self.someProperty = ko.observable("abc"); self.anotherProperty = ko.observable("xyz"); self.someComputedProperty = function(){ return self.someProperty() + self.anotherProperty(); }; }; <input data-bind="value: someProperty"/> <input data-bind="value: anotherProperty"/> <p data-bind="text: someComputedProperty()"></p> Everything here seems to work as you'd expect,