How to create a Scroll to Top Button with React
Tags: react, womenintech, codenewbie, webdev
Published: 2021-08-24 08:27:01

#<h1> Hola Mundo! </h1>
<Enter>
So this is my first coding post and am really excited about it 👩‍🎤✨

Thing is that, when I was creating my Portfolio I decided I didn't want to do a sticky menu because well...not a  fan of it. However I noticed that from the user perspective, scrolling through the page all the way to the top is not nice at all 🙅.

At the same time, while  I was reading some old messages in a WhatsApp group I noticed the Scroll-to-Bottom button that appears on the conversation ![capture of how the button looks like](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/cnan116nnrpkngv7mrwn.png) Eureka!💡, so that was my hipothesis: what if I tried to create a button to do the same but the other way around!

I did it and I loooooooooove it 💓. It's one of my favorites  components and now I use it in a lot of projects because:

- It makes  navigation much more easier 🖱️

- The devil is in the details 😈, this may be small but it adds up a lot to your user experience

- Is really simple to do 🤗

So this is my "How to do a Scroll to top button with React functional components"

<Enter>
___

###What does the button does - The logic behind 🧠
<Enter>
After the user start scrolling, the button will appear in a corner allowing it to click it so they can run all the way to the top without having to scroll anymore.

![Gif of the go-to-top button works](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/uyj50ne3xf3jjoyrsfq4.gif)

For doing so, we need, of course, a button. The button can have a text, an emoji or an icon whatever you feel suits it better.. 

We will also need to hear the scroll position so we can hide🙈 or show🐵 our button and finally we will need to handle the scrolling action itself.

So these are the steps:

1- Create and style the button
2- Hear the user position and handle the display
3- Handle the scroll to top action
4- Send *props* to component

Let's get to it!💪

___

###Creating the button 🔼
<Enter>

I started by creating a new component that I called  "GoTop.js". I highly recommend to create a new component so in the future, you can reuse ♻️ it if you want to.

This is pretty much a dumb component that will render the button itself and that will receive via props the hidding and the action methods 🔨. 

For my button I used a [fontawesome icon](https://fontawesome.com/) as I think it looks really clean and simple. 

```react 
//goTop.js COMPONENT

const GoTop = (props) => {
  return (
    <>
      <div className={props.showGoTop} onClick={props.scrollUp}>
        <button className="goTop">
          <i className="goTop__text fas fa-chevron-up" />
        </button>
      </div>
    </>
  );
};
export default GoTop;
```


 

For the styles 💅 I worked with SASS: my button only has a `display:block;` and the goTop__text class has everything else: position, colours, size, shadows and a little hover action. Don't forget to make it fixed!

![Code showing how I styled my component](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/58bcc52gd6u659zpjx8t.png)

#### Step one: done.
✔️ Create and style the button

<Enter>
 ___

###Hearing the user position 👂 and showing the button
<Enter>
For the button to render we need to know where the user is. We don't want the button to show if there's no way up to go 🛑

So we will start declaring our scroll position with an initial state  of 0 
`const [scrollPosition, setSrollPosition] = useState(0); `

Now, as we also need to show or hide the button, we will declare another state, this time for the "showing".
`const [showGoTop, setshowGoTop] = useState("goTopHidden");`. 

In my oppinion, I think the easiest way to manage this state is to add one or other class, having the "goTopHidden" class with a ` display: none;` style and a "goTop" class that, as you have seen before states a ` display: block;` that makes it visible.

This will be sent 📤 via prop to my component so the div that wraps up the button, receives the corresponding class. 

<Enter>
####Handle the display 👀
<Enter>
This handler will set new states to the states we just declared. For doing so, we are gonna use the `window.pageYOffset;` this property "returns the number of pixels that the document is currently scrolled vertically"  <small>[read more...](https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollY)</small>

So first thing first, our handler  will take this information and set it in our position state. Now that we know where our user is🙋, we can tell the handler  that when the user reaches a certain position something *must* happen. According to our code it will change the class that hides our button.

As you can see on the code below, when the scrollPosition is greater than 50 (px) it will change the element class to "GoTop" else, it will set the class that hides the button.

```react
//DISPLAY HANDLER
const handleVisibleButton = () => {
    const position = window.pageYOffset;
    setSrollPosition(position);

    if (scrollPosition > 50) {
      return setshowGoTop("goTop");
    } else if (scrollPosition < 50) {
      return setshowGoTop("goTopHidden");
    }
  };
```

To wrap up this step we will add an eventListener to our window that will trigger the method. For this we will need to use the *useEffect* Hook with a simple `window.addEventListener` that will call our handleVisibleButton method.

```react
//SCROLL LISTENER
useEffect(() => {
    window.addEventListener("scroll", handleVisibleButton);
  });
```
<Enter>

####Step two: done.
✔️ Hear the user position and handle the display
<Enter>
 ___

###Handling the scroll action🖱️
<Enter>
This handler will be triggered by the user click and its function is very simple: to scroll up the user.

In order to do this we will need to use another Hook: *useRef()*, that we will declare in a constant `const refScrollUp = useRef();` 

Having this constant declared now we have to call it in our JSX in the element we want to use as reference. Understanding that we want to send the user all the way up, we will have to call it in an element that is in the top of  our page 🔝

I decided  to add a `<div>` tag on top of everything as reference.

```react
//REF IN JSX
function App() {
 //code
  return (
    <>
      <div ref={refScrollUp}> </div>
      <Header />
      <AboutUs />
     </>
  );
}

export default App;
```
 
Now it comes the last step: our handling method. In our method we will have to use the property `current` of  our Hook. As we referenced an element of our DOM, React will assign that element as "current".

We also will need to use the `scrollIntoView()` method. This  method will make that the element on which scrollIntoView() is called is visible to the user.

So our handling method will use the reference we created and with the scrollIntoView, we will be 
 able  to actually scroll our user all the way to the top.

Our function will look like this: 

```react
//SCROLL UP HANDLER

const handleScrollUp = () => {
    refScrollUp.current.scrollIntoView({ behavior: "smooth" });
  };
```

<small>P.D: I added a `behavior: "smooth" ` because we want the scroll to look soft.</small>
<Enter>

####Step three: done.
✔️ Handle the scroll-to-top action
<Enter>
 ___

###Sending everything via props ✈️
<Enter>
Now that all the things are in motion we have to send via props two things: the state for the button, so it changes correctly and the handleScrollUp funcion that we will call onClick.

`  <GoTop showGoTop={showGoTop} scrollUp={handleScrollUp} />`

```react
//PROPS
const GoTop = (props) => {
  return (
    <>
      <div className={props.showGoTop} onClick={props.scrollUp}>
      //BUTTON CODE
    </div>
  );
};
export default GoTop;
```
 
<Enter>

####Step four: done.
✔️ Send *props* to component
<Enter>
 ___

###It's done 🎆🎇

After this four steps you should have a Go-to-Top button that is totally functional💯 

This is my take for the Go-to-Top Button in React using functional components. I really hope this works for you and if you have any question, feel free to ask so, if I have the answer I'll answer and if not...we can Google it  together  😅

![Joke code about being able to answer things](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/0ili0oajp1sxkzw81s44.png)