Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <!-- DO NOT REMOVE or change the ID of following div. It is used as placeholder for the app -->
<div id="app"></div>


              
            
!

CSS

              
                html,
body {
  padding: 0;
  margin: 0px;
  display: flex;
  justify-content: center;
  font-family: Roboto, sans-serif;
  flex-direction: column;
}
@media (max-width: 320px) {
  h1 {
    font-size: 14px;
  }
}
#root {
  max-width: 400px;
}
h1 {
  border-style: solid;
  border-width: 0 2px 2px 2px;
  margin-top: 0;
  box-shadow: 0px 3px 4px gray;
  padding: 0 10px;
}
button {
  margin: 5px;
  padding: 5px 10px;
  font-size: 15px;
  border-radius: 5px;
  border: none;
  border-top: 2px solid green;
  background-color: lightgreen;
  height: 40px;
  min-width: 100px;
}

button.bad {
  border-top: 2px solid #880617;
  background: #f88493;
  color: #880617;
}

button.dangerous {
  border-top: 2px solid darkred;
  background-color: red;
  color: white;
}
.robotContainer {
  display: flex;
  justify-content: center;
  align-items: center;
}

.robotContainer img {
  border: 2px solid;
  border-radius: 5px;
}

.controls {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}

.robotSelectorContainer {
  text-align: center;
  margin-bottom: 10px;
}

select {
  font: inherit;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  height: 40px;
}

select.good {
  border: 2px solid green;
  background: lightgreen;
  color: green;
}

select.bad {
  border: 2px solid #880617;
  background: #f88493;
  color: #880617;
}

select:focus {
  outline: none;
}


              
            
!

JS

              
                /************************************/
//            Robot COMPONENT       
/************************************/
const Robot = (props) => {
  const [loadedRobot, setLoadedRobot] = React.useState({});
  const [isLoading, setIsLoading] = React.useState(false);

  const fetchData = () => {
    setIsLoading(true);
    fetch(`https://robohash.org/${props.selectedRobotId}`, {
      "Content-type": "application/octet-stream"
    })
      .then(response => {
        if (response.status !== 200) {
          throw new Error("Could not fetch the Robot");
        }
        return response.blob();
      })
      .then(robot => {
        setIsLoading(false);
        setLoadedRobot(window.URL.createObjectURL(robot));
      })
      .catch(err => console.error(err));
  };

  React.useEffect(() => {
    console.log('Robot: componentWillUpdate');
    fetchData();
  }, [props.selectedRobotId]);

  React.useEffect(() => {
    console.log('Robot: componentDidMount');
    return () => {
      console.log('Robot: componentWillUnmount');
    }
  }, []);
  let content = <p>Loading robot...</p>;
    if (!isLoading && loadedRobot) {
      content = (
        <img
          width="150"
          src={loadedRobot}
          alt=""
          onLoad={function(event) {
            window.URL.revokeObjectURL(event.target.src);
          }}
        />
      );
    } else if (!isLoading && !loadedRobot) {
      content = <p>Failed to load robot!!!</p>;
    }

    return <div className="robotContainer">{content}</div>;
}
/************************************/
//     RobotSelector COMPONENT     
/************************************/
const RobotSelector = ({onRobotChange, selectedRobotsId, robotType}) => {
  const [robots, setRobots] = React.useState([]);
  const [isLoading, setIsLoading] = React.useState(false);
  React.useEffect(() => {
    setIsLoading(true);
    fetch("https://swapi.co/api/species")
      .then(response => {
        if (!response.ok) {
          throw new Error("Failed to fetch.");
        }
        return response.json();
      })
      .then(robotData => {
        const selectedRobots = robotData.results.slice(0, 5).map((robot, index) => ({
            name: robot.name,
            id: index + 1
          }));
          setRobots(selectedRobots);
          setIsLoading(false);
        })
      .catch(err => {
        console.log(err);
      });
  }, []);

  let content = <p>Loading Robots...</p>;
  if (
    !isLoading && robots && robots.length > 0
  ) {
    content = (
      <select
        onChange={onRobotChange}
        value={selectedRobotsId}
        className={robotType}
        >
        {robots.map(robot => (
          <option key={robot.id} value={robot.id}>
            {robot.name}
          </option>
        ))}
      </select>
    );
  } else if (
    !isLoading && (!robots || robots.length === 0)
  ) {
    content = <p>Could not fetch any data.</p>;
  }

  return <div className="robotSelectorContainer">{content}</div>;
}
/************************************/
//            App COMPONENT        
/************************************/
const App = () => {
  const [selectedRobotId, setSelectedRobotId] = React.useState(1);
  const [robotType, setRobotType] = React.useState("good");
  const [destroyed, setDestroyed] = React.useState(false);
  
 const onRobotChange = event => {
    const robotId = event.target.value;
    setSelectedRobotId(robotId);
  };
  const onRobotTypeChange = robotType => {
    setRobotType(robotType);
  };
  const onDestruction = () => {
    setDestroyed(true);
  };

  if (destroyed) {
    return <h1>This bad robot destroyed everything!</h1>;
  }
  return (
    <React.Fragment>
      <h1>React Lifecycle with hooks</h1>
      <RobotSelector
        robotType={robotType}
        selectedRobotId={selectedRobotId}
        onRobotChange={onRobotChange}
        />
      <Robot selectedRobotId={selectedRobotId} />
      <div className="controls">
        <button onClick={onRobotTypeChange.bind(this, "good")}>
          Good Robot
        </button>
        <button
          className="bad"
          onClick={onRobotTypeChange.bind(this, "bad")}
          >
          Bad Robot
        </button>
        {robotType === "bad" && (
          <button className="dangerous" onClick={onDestruction}>
            Destroy
          </button>
        )}
      </div>
    </React.Fragment>
  );
}

ReactDOM.render(<App />, document.getElementById("app"));


              
            
!
999px

Console