如何使组件项与其父项自动更改所有者？

Question

我正在学习 hyperledger composer，但我不知道如何修改链代码以使以下模型工作：

这是我的首席技术官：

asset Item identified by itemId{
o String itemId
o String name
o String idgId
o String serialNumber
o String comment
--> BU owner
--> Item [] items optional

}
abstract participant BU identified by buId{
    o String buId
    o String name
    o String country
    o String city
}

participant Manufacturer extends BU{

}

participant Assembler extends BU{

}

和链码：

function tradeCommodity(trade) {

trade.item.owner = trade.newOwner;
return getAssetRegistry('org.dps.track.Item')
    .then(function (assetRegistry) {

        var tradeNotification = getFactory().newEvent('org.dps.track',       'TradeNotification'); 
        tradeNotification.item = trade.item;
        emit(tradeNotification);

        // persist the state of the commodity
        return assetRegistry.update(trade.item);
    });

}

然后我做了两个项目：I1 和 I2 - 这将是第三个项目 I3 的组成部分像这样：

    {
    "$class": "org.dps.track.Item",
    "itemId": "I1",
    "name": "c1",
    "idgId": "123",
    "serialNumber": "123",
    "comment": "component1",
    "owner": "resource:org.dps.track.Assembler#BU2"
  },
  {
    "$class": "org.dps.track.Item",
    "itemId": "I2",
    "name": "c2",
    "idgId": "456",
    "serialNumber": "456",
    "comment": "component2",
    "owner": "resource:org.dps.track.Assembler#BU2"
  },
  {
    "$class": "org.dps.track.Item",
    "itemId": "I3",
    "name": "complex",
    "idgId": "789",
    "serialNumber": "789",
    "comment": "item consists of items",
    "owner": "resource:org.dps.track.Assembler#BU2",
    "items": [
      "resource:org.dps.track.Item#I1",
      "resource:org.dps.track.Item#I2"
    ]
  }

然后，如果我进行交易，I3 会更改所有者，但其组件仍然是以前的所有者。当 I3 更改所有者时，如何让 I1 和 I2 自动更改所有者。有可能实现这一目标吗？如果有任何帮助或指导，我将不胜感激。

Answer 1

像这样（请注意，这是示例代码，可能有更有效的方法来做到这一点，例如聚合所有受所有权变更影响的 'related Items'，然后执行一个 updateAll() 调用以更新项目注册表 - 示例 here) - 另请注意我使用了 async / await （在节点 8 中可用，因为它更具可读性）。

注意我的交易模型是：

transaction Trade { 
  --> Item item
  --> Assembler newOwner
}

更新：您还需要您的资产 Item 将 --> Assembler owner 作为资源 class（与之建立关系实例）而不是 -->BU 所有者`这是一个抽象 class.

模型文件中（即Assembler是参与者资源）

/**
 * Sample transaction processor function.
 * @param {org.dps.track.Trade } trade The sample transaction instance.
 * @transaction
 */
async function tradeCommodity(trade) {

    const factory = getFactory();
    trade.item.owner = trade.newOwner;
    var list = [];
    if (trade.item.items && trade.item.items.length > 0) {
        trade.item.items.forEach((asset) => {
        list.push(asset);
        });
    }  


    const assetRegistry = await getAssetRegistry('org.dps.track.Item');


    // persist the state of the current ITEM
    await assetRegistry.update(trade.item);

    for (var i = 0; i < list.length; ++i) {

         let res = await assetRegistry.get(list[i].getIdentifier());
         res.owner = factory.newRelationship('org.dps.track', 'Assembler', trade.newOwner.getIdentifier());
         // persist the state of the ITEM with new owner as a relationship
         await assetRegistry.update(res);
    }

}

如何使组件项与其父项自动更改所有者？

How to make component item change owner automatically with its parent?

api

hyperledger

hyperledger-fabric

hyperledger-composer