Get random element from Graphcool?

Question

Is it possible to return a random graphql element from a Graphcool backend? If so, how could this be done?

Alternatively, any tips on howto create custom queries for Graphcool backends?

Answer 1

The best way to do this is by using the API Gateway pattern.

The idea of that approach is to put a gateway server on top of Graphcool's CRUD API and thus customize the API. With this approach, you'd write an additional resolver function that retrieves the random element for you:

const extendTypeDefs = `
  extend type Query {
    randomItem: Item
  }
`

const mergedSchemas = mergeSchemas({
  schemas: [graphcoolSchema, extendTypeDefs],
  resolvers: mergeInfo => ({
    Query: {
      randomItem: {
        resolve: () => {
          return request(endpoint, allItemsQuery).then(data => {
            const { count } = data._allItemsMeta
            const randomIndex = Math.floor((Math.random() * (count-1)) + 0)
            const { id } = data.allItems[randomIndex]
            return request(endpoint, singleItemQuery, { id }).then(data => data.Item)
          })
        },
      }
    },
  }),
})

I created a full example of this here. Let me know if you have any additional questions :)