Switch class on tabs with React.js

Question

So I have a tab-component that has 3 items:

React.DOM.ul( className: 'nav navbar-nav', 
    MenuItem( uid: 'home')
    MenuItem( uid: 'about')
    MenuItem( uid: 'contact)
)

And in the .render of MenuItem:

React.DOM.li( id : @props.uid, className: @activeClass, onClick: @handleClick,
    React.DOM.a( href: "#"[email protected], @props.uid)
)

Every time I click an item, a backbone router gets called, which will then call the tab-component, which in turn will call a page-component.

I'm still trying to wrap my head around the fact there's basically a one-way data-flow. And I'm so used to manipulating the DOM directly.

What I want to do, is add the .active class to the tab clicked, and make sure it gets removed from the inactive ones.

I know the CSS trick where you can use a data- attribute and apply different styling to the attribute that is true or false.

The backbone router already has already gotten the variable uid and calls the right page. I'm just not sure how to best toggle the classes between tabs, because only one can be active at the same time.

Now I could keep some record of which tab is and was selected, and toggle them etc. But React.js already has this record-keeping functionality.

The @handleClick you see, I don't even want to use, because the router should tell the tab-component which one to give the className: '.active' And I want to avoid jQuery, because React.js doesn't need direct DOM manipulation.

I've tried some things with @state but I know for sure there is a really elegant way to achieve this fairly simple, I think I watched some presentation or video of someone doing it.

I'm really have to get used to and change my mindset towards thinking React-ively.

Just looking for a best practice way, I could solve it in a really ugly and bulky way, but I like React.js because it's so simple.

Answer 1

Push the state as high up the component hierarchy as possible and work on the immutable props at all levels below. It seems to make sense to store the active tab in your tab-component and to generate the menu items off data (this.props in this case) to reduce code duplication:

Working JSFiddle of the below example + a Backbone Router: http://jsfiddle.net/ssorallen/4G46g/

var TabComponent = React.createClass({
  getDefaultProps: function() {
    return {
      menuItems: [
        {uid: 'home'},
        {uid: 'about'},
        {uid: 'contact'}
      ]
    };
  },

  getInitialState: function() {
    return {
      activeMenuItemUid: 'home'
    };
  },

  setActiveMenuItem: function(uid) {
    this.setState({activeMenuItemUid: uid});
  },

  render: function() {
    var menuItems = this.props.menuItems.map(function(menuItem) {
      return (
        MenuItem({
          active: (this.state.activeMenuItemUid === menuItem.uid),
          key: menuItem.uid,
          onSelect: this.setActiveMenuItem,
          uid: menuItem.uid
        })
      );
    }.bind(this));

    return (
      React.DOM.ul({className: 'nav navbar-nav'}, menuItems)
    );
  }
});

The MenuItem could do very little aside from append a class name and expose a click event:

var MenuItem = React.createClass({
  handleClick: function(event) {
    event.preventDefault();
    this.props.onSelect(this.props.uid);
  },
  render: function() {
    var className = this.props.active ? 'active' : null;

    return (
      React.DOM.li({className: className},
        React.DOM.a({href: "#" + this.props.uid, onClick: this.handleClick})
      )
    );
  }
});