@relay的目的(pattern:true)

为继电器突变定义胖查询时,要包括字段名称而不指定其任何子字段,则告诉Relay该字段的任何子字段都可能因该突变而发生变化.

不幸的是,省略连接参数,例如find,first和last在friends现场将导致连接参数的依赖字段验证错误edges和pageInfo:

getFatQuery() {
  return Relay.QL`
    fragment on AddFriendMutationPayload {
      viewer { 
        friends { edges, pageInfo }  # Will throw the validation error below
      }
    }
  `;
}

// Uncaught Error: GraphQL validation/transform error ``You supplied the `pageInfo` 
// field on a connection named `friends`, but you did not supply an argument necessary 
// to do so. Use either the `find`, `first`, or `last` argument.`` in file 
// `/path/to/MyMutation.js`.

getFatQuery() {
  return Relay.QL`
    fragment on AddFriendMutationPayload @relay(pattern: true) {
      viewer {
        friends { edges, pageInfo }  # Valid!
      }
    }
  `;
}