By using styled components, how can I add some opacity to a background color that comes from an external prop? - reactjs

Question

This is my code, below it you will find the question
import { printIntrospectionSchema } from 'graphql';
import React, { useContext, useState } from 'react';
import styled from 'styled-components';
import { Context } from '../../../Context/Context';
// DATA
function DurationIntervalSelection() {
const tabsData = [
{
text: 'Duration',
},
{
text: 'Interval',
},
];
// STATE
const [selectedIndex, setselectedIndex] = useState(0);
const { selected } = useContext(Context);
console.log(selected.color, 'selected color');
// FUNCTION
const handleIndexSelection = (index) => {
setselectedIndex(index);
};
return (
<Container>
<TabsContainer backgroundColor={selected.backgroundColor}>
<Indicator
backgroundColor={selected.color}
style={{
left: `${selectedIndex * 50}%`,
}}
/>
{tabsData.map((tab, index) => {
return (
<Tab
style={{
color: selectedIndex === index ? 'white' : 'black',
}}
onClick={() => handleIndexSelection(index)}
key={tab.text}
>
<p style={{ zIndex: 100 }}>{tab.text}</p>
</Tab>
);
})}
</TabsContainer>
</Container>
);
}
const Container = styled.div`
margin-top: 10px;
border: 1px solid #f2f2f7;
border-radius: 10px;
box-sizing: border-box;
padding: 10px 0;
`;
const Indicator = styled.div`
width: 50%;
position: absolute;
/* z-index: -1; */
height: 100%;
border-radius: 20px;
cursor: pointer;
transition: all 0.3s;
background-color: ${(props) => props.backgroundColor};
`;
const TabsContainer = styled.div`
display: flex;
width: 100%;
justify-content: space-between;
position: relative;
box-shadow: 1px 1px 3px rgba(0, 0, 0, 0.2);
border-radius: 20px;
overflow: hidden;
background-color: ${(props) => props.backgroundColor};
`;
const Tab = styled.div`
display: flex;
width: 50%;
justify-content: center;
cursor: pointer;
align-items: center;
padding: 10px;
`;
export default DurationIntervalSelection;
As you can see from the above code i pass backgroundColor as a prop that takes some color from a React state.
<TabsContainer backgroundColor={selected.backgroundColor}>
And in the styled component I do:
background-color: ${(props) => props.backgroundColor};
But my question is, since i need to follow a design made by a colleague, how do i add opacity to the above background color without affecting the opacity of the whole div: TabsContainer. I mean, if i add on the TabsContainer -> opacity: 0.3 - for instance the whole TabsContainer div will be affected by the opacity, including the Tab div, while what I want is just to change opacity on the color itself so i do not affect any child. I hope it makes sense. Is there a way?

Answer 1

Okay if your hex value comes from your backend, you can either create your own javascript function that converts hex to rgba or you can use a library like polished. They have a function named rgba that converts a hex string and adds an alpha value to it
import { rgba } from 'polished'
const div = styled.div`
background: ${(props) => rgba(props.backgroundColor, 0.3)};
`
Or you can apply it directly to the prop
<TabsContainer backgroundColor={rgba(selected.backgroundColor, 0.3)}>
Example CodeSandbox.

Answer 2

Since the data from the backend where right but I could not find a solution I have realised that I could have added to
<TabsContainer backgroundColor="rgba(255,255,255, 0.5)">
A background color on the white notes with opacity so to emphasise the color behind it in a lighter way