Q: Defining data requirement in Relay.Route?

[facebook]

Q: Defining data requirement in Relay.Route?

[devknoll]

But I assume that calling getFragment directly in Relay.Route also from other components is also reasonable?

At the moment, there's a 1:1 mapping between a route root query and a fragment. You should also check #20 (comment), because the Component argument is going away too. So, multiple routes probably aren't what you're looking for.

Digging through the source code, you might be able to achieve what you're looking for using variables, doing something like this:

var MyComponentContainer = Relay.createContainer(MyComponent, {
  initialVariables: {
    showPopup: false,
  },
  fragments: {
    album: (variables) => Relay.QL`
      fragment on Album {
        name,
        ${SongList.getFragment('songs').if(variables.showPopup)}
      }
    }``
  }
});

And then running setVariables when you need to get the songs. Note: this is untested, and I have no idea if this will be a supported feature.

[devknoll]

Another possibility would be to just use connections, and do something like:

var MyComponentContainer = Relay.createContainer(MyComponent, {
  initialVariables: {
    songsToShow: 0,
  },
  fragments: {
    album: (variables) => Relay.QL`
      fragment on Album {
        name,
        songs(first: $songsToShow) {
          edges {
            node {
              ${SongList.getFragment('songs')}
            }
          }
        }
      }
    }`
  }
});

and use setVariables again to grab the list.

[jardakotesovec]

These conditional fragments would be great pattern for these use cases.

   ${SongList.getFragment('songs').if(variables.showPopup)}

Could someone from fb please comment if thats pattern we can use at the moment/future?

Thanks

[josephsavona]

@jardakotesovec Sorry for missing this: yes, ${Child.getFragment(..).if(variables.foo)} is supported. Be sure to check the value of variables.showPopup in your render code and skip rendering <SongList> when it's false, otherwise you'll get errors about missing data.

[josephsavona]

@jardakotesovec did that solution work for you? I'm going to close this issue since the question is answered, but feel free to reopen if you have any additional questions!