<h4>First instance, without parameters</h4>
<div data-bind='component: "message-editor"'></div>
<h4>Second instance, passing parameters</h4>
<div data-bind='component: {
name: "message-editor",
params: { initialText: "Hello, world!" }
}'></div>

ko.components.register('message-editor', {
viewModel: function(params) {
this.text = ko.observable(params && params.initialText || '');
},
template: 'Message: <input data-bind="value: text" /> '
+ '(length: <span data-bind="text: text().length"></span>)'
});
ko.applyBindings();

<div data-bind='component: "my-component"'></div>

<div data-bind='component: observableWhoseValueIsAComponentName'></div>

<div data-bind='component: {
name: "shopping-cart",
params: { mode: "detailed-list", items: productsList }
}'></div>

ko.components.register('special-offer', {
template: '<div class="offer-box" data-bind="text: productName"></div>'
});

<div data-bind='component: {
name: "special-offer-callout",
params: { productName: someProduct.name }
}'></div>

<special-offer params='productName: someProduct.name'></special-offer>

<!-- ko component: "message-editor" -->
<!-- /ko -->

<!-- ko component: {
name: "message-editor",
params: { initialText: "Hello, world!", otherParam: 123 }
} -->
<!-- /ko -->

<div data-bind="component: { name: 'my-special-list', params: { items: someArrayOfPeople } }">
<!-- Look, here's some arbitrary markup. By default it gets stripped out
and is replaced by the component output. -->
The person <em data-bind="text: name"></em>
is <em data-bind="text: age"></em> years old.
</div>

var someExternalObservable = ko.observable(123);
function SomeComponentViewModel() {
this.myComputed = ko.computed(function() {
return someExternalObservable() + 1;
}, this);
this.myPureComputed = ko.pureComputed(function() {
return someExternalObservable() + 2;
}, this);
this.mySubscription = someExternalObservable.subscribe(function(val) {
console.log('The external observable changed to ' + val);
}, this);
this.myIntervalHandle = window.setInterval(function() {
console.log('Another second passed, and the component is still alive.');
}, 1000);
}
SomeComponentViewModel.prototype.dispose = function() {
this.myComputed.dispose();
this.mySubscription.dispose();
window.clearInterval(this.myIntervalHandle);
// this.myPureComputed doesn't need to be manually disposed.
}
ko.components.register('your-component-name', {
viewModel: SomeComponentViewModel,
template: 'some template'
});