中继突变中的 RANGE_ADD 问题答案

【问题标题】：Issue with RANGE_ADD in Relay Mutations中继突变中的 RANGE_ADD 问题
【发布时间】：2017-06-27 02:13:57
【问题描述】：

我正在阅读中继文档并在 RANGE_ADD 中找到以下代码。

class IntroduceShipMutation extends Relay.Mutation {
  // This mutation declares a dependency on the faction
  // into which this ship is to be introduced.
  static fragments = {
    faction: () => Relay.QL`fragment on Faction { id }`,
  };
  // Introducing a ship will add it to a faction's fleet, so we
  // specify the faction's ships connection as part of the fat query.
  getFatQuery() {
    return Relay.QL`
      fragment on IntroduceShipPayload {
        faction { ships },
        newShipEdge,
      }
    `;
  }
  getConfigs() {
    return [{
      type: 'RANGE_ADD',
      parentName: 'faction',
      parentID: this.props.faction.id,
      connectionName: 'ships',
      edgeName: 'newShipEdge',  
      rangeBehaviors: {
        // When the ships connection is not under the influence
        // of any call, append the ship to the end of the connection
        '': 'append',
        // Prepend the ship, wherever the connection is sorted by age
        'orderby(newest)': 'prepend',
      },
    }];
  }
  /* ... */
}

现在在这里提到edgeName 是添加新节点到连接所必需的。看起来不错。

现在，我将文档往下移，到达了这个突变的 GraphQL 实现。

mutation AddBWingQuery($input: IntroduceShipInput!) {
  introduceShip(input: $input) {
    ship {
      id
      name
    }
    faction {
      name
    }
    clientMutationId
  }
}

现在根据文档，这个突变给了我输出

{
  "introduceShip": {
    "ship": {
      "id": "U2hpcDo5",
      "name": "B-Wing"
    },
    "faction": {
      "name": "Alliance to Restore the Republic"
    },
    "clientMutationId": "abcde"
  }
}

我看不到edgeName 出现在这里。

我在我的项目中使用了石墨烯。那边我也只看到类似的东西

class IntroduceShip(relay.ClientIDMutation):
  class Input:
    ship_name = graphene.String(required=True)
    faction_id = graphene.String(required=True)

ship = graphene.Field(Ship)
faction = graphene.Field(Faction)

@classmethod
def mutate_and_get_payload(cls, input, context, info):
    ship_name = input.get('ship_name')
    faction_id = input.get('faction_id')
    ship = create_ship(ship_name, faction_id)
    faction = get_faction(faction_id)
    return IntroduceShip(ship=ship, faction=faction)

在这里，我也无法在任何地方看到edgeName。

有什么帮助吗？我正在研究第一个突变，所以想确认我错过了什么或者这里有什么问题？

【问题讨论】：

标签： graphql relayjs relay

【解决方案1】：

这个例子可能会被简化或有点过时，因为在实践中需要返回边缘，而这正是中继获取的内容（RANGE_ADD 中的其他字段更多是一种声明和不一定要获取）。

在石墨烯中你可以这样做：

# Import valid as of graphene==0.10.2 and graphql-relay=0.4.4
from graphql_relay.connection.arrayconnection import offset_to_cursor

class IntroduceShip(relay.ClientIDMutation):
    class Input:
        ship_name = graphene.String(required=True)
        faction_id = graphene.String(required=True)

    ship = graphene.Field(Ship)
    faction = graphene.Field(Faction)
    new_ship_edge = graphene.Field(Ship.get_edge_type().for_node(Ship))

    @classmethod
    def mutate_and_get_payload(cls, input, context, info):
        ship_name = input.get('ship_name')
        faction_id = input.get('faction_id')
        ship = create_ship(ship_name, faction_id)
        faction = get_faction(faction_id)

        ship_edge_type = Ship.get_edge_type().for_node(Ship)
        new_ship_edge = edge_type(
            # Assuming get_ships_number supplied
            cursor=offset_to_cursor(get_ships_number())
            node=ship
        )

        return cls(ship=ship, faction=faction, new_ship_edge=new_ship_edge)

【讨论】：