knockout.js Bindings If / ifnot
Example
You can use the if binding to determine whether or not the child elements of the node should be created.
<div class="product-info">
<h2> Product1 </h2>
<img src="../products/product1.jpg"/>
<span data-bind="if:featured">
<span class="featured"></span>
</span>
<span data-bind="ifnot:inStock">
<span class="out-of-stock"></span>
</span>
</div>
<script>
ko.applyBindings({
product: {
featured: ko.observable(true),
inStock: ko.observable(false)
}
});
</script>
The inverse of the if binding is ifnot
<div data-bind="ifnot: someProperty">...</div>
is equivalent to
<div data-bind="if: !someProperty()">...</div>
Sometimes, you'll wan't to control the presence of elements without having to create a container (typically for <li> elements in a <ul> or <option> elements inside a <select>)
Knockout enables this with containerless control flow syntax based on comment tags like so:
<select>
<option value="0">fixed option</option>
<!-- ko if: featured-->
<option value="1">featured option</option>
<!-- /ko -->
</select>
