BeeNag BeeNag - 3 months ago 9
React JSX Question

Finding an object in array and taking values from that to present in a select list

I have a string value (e.g. "Table 1") that I need to use to find a specific object in an array that looks like so:

[
{
lookups: [],
rows: [{data: {a: 1, b: 2}}, {data: {a: 3, b: 4}}],
title: "Table 1",
columns: [{name: "a"}, {name: "b"}]
},
{
lookups: [],
rows: [{data: {c: 5, d: 6}}, {data: {c: 7, d: 8}}],
title: "Table 2",
columns: [{name: "c"}, {name: "d"}]
}
]


Once I have found that object I then need to take the values from the columns key and display them in a select list.

I know how to do the second part, but it is getting access to the object in the first place that I am having trouble with. I am trying to do this within a React component render.

Any help with this would be greatly appreciated.

Thanks for your time.

Answer

If you need get all items from array which have title: 'Table 1', you can use .filter(Example)., if you need only first item where title: 'Table 1' you can use .find(Example)

var App = React.createClass({
  columns: function(condition) {
    return this.props.data
      .filter((e) => e.title === condition)
      .map(e => e.columns)
      .reduce((prev, current) => prev.concat(current), [])
      .map((column, index) => <p key={ index }>{ column.name }</p>)
  },

  render: function() {
    const condition = 'Table 1';
    return <div>{ this.columns( condition ) }</div>;
  }
});

const data = [{
  lookups: [], 
  rows: [{data: {a: 1, b: 2}}, {data: {a: 3, b: 4}}], 
  title: "Table 1", 
  columns: [{name: "a"}, {name: "b"}]
}, {
  lookups: [],
  rows: [{data: {c: 5, d: 6}}, {data: {c: 7, d: 8}}],
  title: "Table 2",
  columns: [{name: "c"}, {name: "d"}]
}, {
  lookups: [],
  rows: [],
  title: "Table 1",
  columns: [{name: "m"}, {name: "n"}]
}];

ReactDOM.render(
  <App data={ data } />,
  document.getElementById('container')
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="container"></div>