Category: React

Sometimes, we want to turn off background hover for bar charts with Recharts.

In this article, we’ll look at how to turn off background hover for bar charts with Recharts.

How to turn off background hover for bar charts with Recharts?

To turn off background hover for bar charts with Recharts, we can set the cursor prop of the Tooltip component to false.

For instance, we write:

import React from "react";
import {
  BarChart,
  Bar,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  Legend
} from "recharts";

const data = [
  { name: "Page A", uv: 4000, pv: 2400, amt: 2400 },
  { name: "Page B", uv: 3000, pv: 1398, amt: 2210 },
  { name: "Page C", uv: 2000, pv: 9800, amt: 2290 },
  { name: "Page D", uv: 2780, pv: 3908, amt: 2000 },
  { name: "Page E", uv: 1890, pv: 4800, amt: 2181 },
  { name: "Page F", uv: 2390, pv: 3800, amt: 2500 },
  { name: "Page G", uv: 3490, pv: 4300, amt: 2100 }
];

const SimpleBarChart = () => {
  return (
    <BarChart
      width={600}
      height={300}
      data={data}
      margin={{ top: 5, right: 30, left: 20, bottom: 5 }}
    >
      <CartesianGrid strokeDasharray="3 3" />
      <XAxis dataKey="name" />
      <YAxis />
      <Tooltip cursor={false} />
      <Legend />
      <Bar dataKey="pv" fill="#8884d8" />
      <Bar dataKey="uv" fill="#82ca9d" />
    </BarChart>
  );
};

export default function App() {
  return <SimpleBarChart />;
}

We define the SimpleBarChart component that renders the BarChart component.

We set the data prop to data to render the data array’s entries in the bar chart.

And we render the x-axis with the XAxis component.

The dataKey prop is set to 'name' to take the name property of each entry as the x-axis values.

We add the bars with the Bar component and we set the dataKey prop to the name of the property with the values we want to render as the bar heights.

Finally, we add the Tooltip component to add the tooltips that are shown when we hover over each bar.

And we set the cursor prop to false to disable highlighting the background when we hover over a bar.

Conclusion

To turn off background hover for bar charts with Recharts, we can set the cursor prop of the Tooltip component to false.

Sometimes, we want to handle null values in React.

In this article, we’ll look at how to handle null values in React.

How to handle null values in React?

To handle null values in React, we can use the optional chaining operator.

For instance, we write:

import React from "react";

const customer = {
  name: "Carl",
  details: {
    age: 22,
    location: "Paradise Falls"
  }
};

export default function App() {
  return <div>{customer.details?.address?.city}</div>;
}

We render the value of customer.details?.address?.city without crashing since we a used the optional chaining operator (?.) instead of the regular dot operator for accessing nested properties.

The optional chaining operator returns undefined when it tries to access a property that doesn’t exist or it’s set to null or undefined.

Conclusion

To handle null values in React, we can use the optional chaining operator.

Sometimes, we want to fix the anchor tag isn’t calling the onClick function issue in React.

In this article, we’ll look at how to fix the anchor tag isn’t calling the onClick function issue in React.

How to fix the anchor tag isn’t calling the onClick function issue in React?

To fix the anchor tag isn’t calling the onClick function issue in React, we can call e.preventDefault in our click event handler function.

For instance, we write:

import React from "react";

export default function App() {
  const onClick = (e) => {
    e.preventDefault();
    console.log("clicked");
  };

  return (
    <a href="https:/example.com" onClick={onClick}>
      click me
    </a>
  );
}

to add the onClick function that calls e.preventDefault to stop the default behavior of going to the page with the URL set as the value of the href attribute.

And then we set the onClick prop of the a element to the onClick function.

As a result, we see 'clicked' logged in the console instead of going to https://example.com when we click on the link.

Conclusion

To fix the anchor tag isn’t calling the onClick function issue in React, we can call e.preventDefault in our click event handler function.

Sometimes, we want to call a method from another class component in React.js.

In this article, we’ll look at how to call a method from another class component in React.js.

How to call a method from another class component in React.js?

To call a method from another class component in React.js, we can pass the class method as a prop to a child component.

For instance, we write:

import React, { Component } from "react";

class Class1 extends Component {
  render() {
    const { onClick } = this.props;
    return <div onClick={onClick}>click me</div>;
  }
}

class Class2 extends Component {
  onClick = () => {
    console.log("class 2 click");
  };

  render() {
    return <Class1 onClick={this.onClick} />;
  }
}

export default function App() {
  return <Class2 />;
}

We have components Class1 and Class2.

And Class1 is a child of Class2.

To pass the onClick method as a prop to Class1, we add onClick={this.onClick}.

Then in Class1, we get the onClick method from this.props and set that as the value of the onClick prop of the div.

Now when we click on the div, we see 'class 2 click' logged.

Conclusion

To call a method from another class component in React.js, we can pass the class method as a prop to a child component.

Sometimes, we want to use escape characters in JSX React components.

In this article, we’ll look at how to use escape characters in JSX React components.

How to use escape characters in JSX React components?

To use escape characters in JSX React components, we can use the same ones as plain JavaScript.

JavaScript escape characters include:

• ' single quote
• " double quote
• \ backslash
• \n new line
• \r carriage return
• \t tab
• \b backspace
• \f form feed

We can also use HTML escape characters in JSX.

To do so, we can put them directly between the element’s tags.

For instance, we can write:

import React from "react";

export default function App() {
  return <div>First &middot; Second</div>;
}

Then we get ‘First · Second’ as a result.

Conclusion

To use escape characters in JSX React components, we can use the same ones as plain JavaScript.

We can also use HTML escape characters in JSX.

To do so, we can put them directly between the element’s tags.