Nested contexts allow developers to wrap a part of a view in a special construction, which offers some additional behavior.
It is possible to create the following types of nested contexts:
Foreach: This nested context walks through all collection elements and provides easy access to HTML elements:Razor: @using (var items = ko.Foreach(m => m.Items)) { <tr> <td @items.Bind.Text(items.GetIndex())> </td> <td @items.Bind.Text(m => m)> </td> </tr> } Html: <!-- ko foreach: Items --> <tr> <td data-bind="text : $index()"> </td> <td data-bind="text : $data"> </td> </tr> <!-- /ko -->With: This allows easy referring to a subentity of the main model:Razor: @using (var subModel = ko.With(m => m.SubModel)) { using (var subSubModel = subModel.With(m => m.SubSubModel)) { @subSubModel.Html.Span(m => ko.Model.ModelName + " " + subModel.Model.SubModelName + " " + m.SubSubModelName) } } Html: <!-- ko with: SubModel --> <!-- ko with: SubSubModel --> <span data-bind="text : $parents[1].ModelName()+' '+$parent.SubModelName()+' '+SubSubModelName()"></span> <!-- /ko --> <!-- /ko -->If: With this, some elements will be displayed according to a specified condition:Razor: @using (ko.If(model => model.Condition1 || model.Condition2)) { <p>Text</p> } Html: <!-- ko if: Condition1()||Condition2() --> <p>Text</p> <!-- /ko -->