30-seconds-of-code/snippets/MappedTable.md

MappedTable

Renders a table with rows dynamically created from an array of objects and a list of property names.

Use Object.keys(), Array.prototype.filter(), Array.prototype.includes() and Array.prototype.reduce() to produce a filteredData array, containing all objects with the keys specified in propertyNames. Render a <table> element with a set of columns equal to the amount of values in propertyNames. Use Array.prototype.map to render each value in the propertyNames array as a <th> element. Use Array.prototype.map to render each object in the filteredData array as a <tr> element, containing a <td> for each key in the object.

function MappedTable({ data, propertyNames }) {
  let filteredData = data.map(v =>
    Object.keys(v)
      .filter(k => propertyNames.includes(k))
      .reduce((acc, key) => ((acc[key] = v[key]), acc), {})
  );
  return (
    <table>
      <thead>
        <tr>{propertyNames.map(val => <th key={`h_${val}`}>{val}</th>)}</tr>
      </thead>
      <tbody>
        {filteredData.map((val, i) => (
          <tr key={`i_${i}`}>
            {propertyNames.map(p => <td key={`i_${i}_${p}`}>{val[p]}</td>)}
          </tr>
        ))}
      </tbody>
    </table>
  );
}

const people = [
  { name: 'John', surname: 'Smith', age: 42 },
  { name: 'Adam', surname: 'Smith', gender: 'male' }
];
const propertyNames = ['name', 'surname', 'age'];
ReactDOM.render(
  <MappedTable data={people} propertyNames={propertyNames} />,
  document.getElementById('root')
);

Notes:

• This component does not work with nested objects and will break if there are nested objects inside any of the properties specified in propertyNames.