When comparing Marko Widgets vs CanJS, the Slant community recommends CanJS for most people. In the question“What are the best JavaScript libraries for building a UI?” CanJS is ranked 12th while Marko Widgets is ranked 17th. The most important reason people chose CanJS is:
CanJS supports all modern browsers and IE9+.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Very fast on the server
Using Marko and Marko Widgets to render UI components on the server was shown to be 10x faster than React. A benchmark application was built using both Marko+Marko Widgets and React and the results of rendering a page of 100 search results on the server was measured and compared. Both the Marko Widgets code and the React code used a very similar UI components-based appraoch.
Pro Stateful UI components
Marko Widgets supports stateful UI components. Marko Widgets will automatically rerender a UI component if its internal state changes. A UI component's state is stored in the this.state
property that is a vanilla JavaScript object. All changes to the state should go through the this.setState(name, value)
method (or this.replaceState(newState)
)
Pro Very fast in the browser
Marko Widgets utilizes the morphdom module for updating the DOM and that module was shown to be very competitive with React and virtual-dom.
Pro The real DOM is the source of truth
Marko Widgets does not rely on a virtual DOM abstraction. Instead, the real DOM is always the source of truth. When updating the DOM, the newly rendered DOM is compared with the real DOM.
Pro DOM diffing/patching
Marko Widgets updates the DOM using a DOM diffing/patching algorithm to minimize the number of changes to the DOM when rerendering a UI component due to state changes. The DOM diffing/patching is handled by the independent morphdom library.
Pro Simple JavaScript API for rendering a UI component
The following code illustrates how the render(input)
method exported by a UI component's JavaScript module can be used to render a UI component and insert the resulting HTML into the DOM:
require('./app-hello')
.render({
name: 'John'
})
.appendTo(document.body)
Pro Batched updates
Updates to the DOM are deferred until all state changes have completed for the current tick. That is, changing a widget's state will not cause the UI component's DOM to immediately be updated.
Pro Declarative eventing binding
Marko Widgets offers a simple mechanism for declaratively binding DOM event and custom event listeners to widget handler methods. For example:
<button type="button" w-onClick="handleClick">
Click Me
</button>
And then in the JavaScript:
module.exports = require('marko-widgets').defineComponent({
// ...
handleClick: function(event, el) {
this.doSomething();
}
});
Pro Marko templating engine for the view
Marko is a fast and lightweight, general purpose HTML-based templating engine that compiles templates to CommonJS modules and supports streaming, async rendering and custom tags. Marko is used for rendering UI components and Marko Widgets is used to bind client-side behavior to rendered UI components. Marko can be used independently of Marko Widgets and this makes it suitable in all situations where HTML rendering is needed.
Pro Efficient binding of behavior for UI components rendered on the server.
When utilizing server-side rendering of a UI, Marko Widgets does not require that the UI be rerendered again in the browser just to bind behavior. Instead, extra information is passed down from the server to the client to allow Marko Widgets to efficiently bind widgets to UI components rendered on the server.
Pro Lightweight (~10 KB gzipped)
The runtime for Marko Widgets is extremely small. The runtime is very small and this makes Marko Widgets much simpler and easier to understand and debug. Marko Widgets offloads much of the work and complexity to compile time code so that the work required at runtime is minimal.
Pro Easily reference nested DOM elements and nested widgets
Marko Widgets supports the concept of "scoped" IDs. With scoped IDs, a nested DOM element or nested widget can be given an ID that is unique within the scope of the containing widget. At runtime the actual ID will be the scoped ID prefixed with the ID of the parent widget. A reference nested widget can be obtained using the this.getWidget(scopedId)
method and a reference to a nested DOM element can be obtained using the this.getEl(scopedId)
method.
For example:
<div class="my-app" w-bind>
<button type="button" w-onClick="handleButtonClick">
Click Me
</button>
<alert-overlay visible="false" w-id="alert">
This is a test alert.
</alert-overlay>
<div w-id="clickMessage" style="display: none;">
You clicked the button!
</div>
</div>
And then in the JavaScript code:
module.exports = require('marko-widgets').defineComponent({
// ...
handleButtonClick: function(event, el) {
var alertWidget = this.getWidget('alert');
// Call the `show()` function implemented by the alert widget:
alertWidget.show();
var clickMessageEl = this.getEl('clickMessage');
clickMessageEl.style.display = 'block';
}
});
Pro Efficient event delegation
Marko Widgets supports efficient event delegation to avoid attaching DOM event listeners to each DOM node. Instead, Marko Widgets attaches event listeners on the document.body
event for events that bubble. Events captured at the root are efficiently delegated out to widgets.
Pro UI components can be embedded in a Marko template using a custom tag
The following code illustrates how a UI component can be embedded in a Marko template:
<div>
<app-hello name="Frank"/>
</div>
Pro Great browser support
CanJS supports all modern browsers and IE9+.
Pro CanJS can be used with any other library
CanJS is a collection of individual libraries, each separately available as npm packages. It's easy to use just what you need.
Pro Real time support
CanJS's model layer (can-connect), support real-time updates to lists without adding any additional code.