> For the complete documentation index, see [llms.txt](https://atomico.gitbook.io/doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://atomico.gitbook.io/doc/guides/atomico-and-react/from-react-to-atomico/virtualdom-api-differences.md).

# VirtualDOM api differences

Guide that defines some differences that exist between Atomico and React when working with the DOM.

Atomico's virtualDOM is:

1. Close to standard DOM .
2. Additional coverage to webcomponents.

### Components as constructors

Atomico does not support the use of functions to instantiate the component as we traditionally do in React, so that the component can be instantiated as a constructor it must be a webcomponent or a real Node.

{% tabs %}
{% tab title="❌ Not supported" %}

```jsx
function Component(){
    const [ state, setState ] = useState();
    return <host></host>
}

function App(){
    return <host>
        <Component/>
    </host>
}
```

{% endtab %}

{% tab title="✔️ Spported" %}

```jsx
// ⚠️ stateless component
function Component(){ 
    return <host></host>
}

function App(){
    return <host>
        <Component/>
    </host>
}
```

{% endtab %}

{% tab title="✔️ Spported" %}

```jsx
function component(){
    return <host></host>
}

const Component = c(component);
customElements.define("my-component",Component)

function app(){
    return <host>
        <Component/>
    </host>
}
```

{% endtab %}

{% tab title="✔️ Supported" %}

```jsx
function app(){
    const Div = document.createElement("div");
    return <host>
        <Image/>
        <Div/>
    </host>
}
```

{% endtab %}
{% endtabs %}

### Event Association

Like React in Atomico you need to use the prefix on to announce an event, but there is a difference **Atomico does not manipulate the name of the event so `onClick` is different from `onclick`**, the purpose of this difference is to support custom events.

```jsx
<div>
    <button onclick={console.log}>click</button>
    <button onMyCustomEvent={console.log}>click</button>
    <button onmy-event={console.log}>click</button>
    <button onmouseover={console.log}>click</button>
</div>
```

### Keyes

the `key` property in Atomicoo can be of type String, Number, Symbol or other immutable reference.

```jsx
<div>
    <div key={1}>1</div>
    <div key={symbol}>1</div>
    <div key={immutable}>1</div>
</div>
```

### dangerouslySetInnerHTML

```jsx
<div innerHTML={`<h1>html!</h1>`}/>
```


---

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