Using Fragments in GraphQL Queries

Introduction

There's a feature that you can take advantage in your journey using GraphQL queries: Fragments

One example of a useful scenario is when you need to query specific ElementGroups from the AEC Data Model. With Fragments you can refer to specific elementgroups/elements by id without duplicated code in your payload.

How it works

Lets explore the scenario introduced previously.

We need to query the properties from elements from Walls category in two specific ElementGroups.

Using Fragments, our query could look like the one below:

fragment WallsFilter on ElementGroup{
  elements(filter:{query:"property.name.category==Walls"}){
    results{
      name
      properties{
        results{
          name
          value
          definition{
            units{
              name
            }
          }
        }
      }
    }
  }
}

query WallsfromElementGroups($elementGroupIdOne:ID!, $elementGroupIdTwo:ID!){
  Snowdon: elementGroupAtTip(elementGroupId:$elementGroupIdOne){
    name
    ...WallsFilter
  }
  RAC: elementGroupAtTip(elementGroupId:$elementGroupIdTwo){
    name
    ...WallsFilter
  }
}

Where the variables would contain your elementgroups ids:

{
  "elementGroupIdOne":"YOUR ELEMENTGROUP ID HERE",
  "elementGroupIdTwo":"YOUR ELEMENTGROUP ID HERE"
}

This approach can be used to improve your queries, removing duplicated content and providing an organized structure. 

You can check a complete demo in the video below: