為多級JSON創建輕松的元數據

Question

我不熟悉，也不十分確定如何為服務器返回的JSON數據創建javascript元數據。 由於服務器未提供我需要的元數據，因此我必須創建一個自定義元數據。 我們使用oData。 有人可以幫我基於此JSON數據創建JavaScript元數據嗎？

 { id: "5091bed7-e035-45c6-b2c5-d1301e4170e6", name: "Mike", address: { city: "San Jose", state: "CA" }, orders: [ { id: "1889e425-e8ad-4b79-b797-fe9aa6b0e433", date: "2015/04/12 00:00:00", items: [ { id: "a71aa2eb-9f8d-4234-aa83-6dfc5cd8abcc", description: "chocolate", price: "5.00" }, { id: "5091bed7-e035-45c6-b2c5-d1301e414444", description: "cookie", price: "1.00" } ] }, { id: "5ed077b0-72c4-43d0-fe96-6bebce6e3c86", date: "2015/05/22 00:00:00", items: [ { id: "bc5ed003-1302-4686-8294-4a0186e550a2", description: "pencil", price: "0.50" } ] } ] } 

Answer 1

在Breeze中，每個對象都將作為實體 （如果有標識符）或復雜類型 （如果沒有標識符）進行處理。 在您的情況下，我為“客戶”（頂級對象），“訂單”和“ OrderItem”創建了實體。 我已經為“地址”創建了ComplexType。

請注意，每個傳入對象應具有“ $ type”屬性，以告知Breeze它是什么實體類型或復雜類型。 否則，您將需要自定義[JsonResultsAdapter]來告知Breeze類型。

我的元數據與您的對象不同，因為我假設外鍵可用於將Customer連接到Order到OrderItem，反之亦然。 這使實體更易於使用，但是如果服務器無法提供，則應從元數據中省略它們。

{
  "structuralTypes": [
    {
      "shortName": "Address",
      "namespace": "MyApp",
      "isComplexType": true,
      "dataProperties": [
        {
          "name": "city",
          "dataType": "String",
          "maxLength": 15
        },
        {
          "name": "state",
          "dataType": "String",
          "maxLength": 15
        }
      ]
    },
    {
      "shortName": "Customer",
      "namespace": "MyApp",
      "autoGeneratedKeyType": "KeyGenerator",
      "defaultResourceName": "Customers",
      "dataProperties": [
        {
          "name": "id",
          "dataType": "Guid",
          "isNullable": false,
          "isPartOfKey": true
        },
        {
          "name": "name",
          "dataType": "String",
          "maxLength": 30
        },
        {
          "name": "location",
          "complexTypeName": "Address:#MyApp"
        }
      ],
      "navigationProperties": [
        {
          "name": "orders",
          "entityTypeName": "Order:#MyApp",
          "isScalar": false,
          "associationName": "AN_Customer_Order"
        }
      ]
    },
    {
      "shortName": "Order",
      "namespace": "MyApp",
      "autoGeneratedKeyType": "Identity",
      "defaultResourceName": "Orders",
      "dataProperties": [
        {
          "name": "id",
          "dataType": "Guid",
          "isNullable": false,
          "isPartOfKey": true
        },
        {
          "name": "customerID",
          "dataType": "Guid"
        },
        {
          "name": "date",
          "dataType": "DateTime"
        }
      ],
      "navigationProperties": [
        {
          "name": "customer",
          "entityTypeName": "Customer:#MyApp",
          "isScalar": true,
          "associationName": "AN_Customer_Order",
          "foreignKeyNames": [
            "customerID"
          ]
        },
        {
          "name": "items",
          "entityTypeName": "OrderItem:#MyApp",
          "isScalar": false,
          "associationName": "AN_Order_OrderItem"
        }
      ]
    },
    {
      "shortName": "OrderItem",
      "namespace": "MyApp",
      "autoGeneratedKeyType": "None",
      "defaultResourceName": "OrderItems",
      "dataProperties": [
        {
          "name": "id",
          "dataType": "Guid",
          "isNullable": false,
          "isPartOfKey": true
        },
        {
          "name": "orderID",
          "dataType": "Guid",
          "isNullable": false
        },
        {
          "name": "description",
          "dataType": "String",
          "isNullable": false
        },
        {
          "name": "price",
          "dataType": "Decimal",
          "isNullable": false
        }
      ],
      "navigationProperties": [
        {
          "name": "order",
          "entityTypeName": "Order:#MyApp",
          "isScalar": true,
          "associationName": "AN_Order_OrderItem",
          "foreignKeyNames": [
            "orderID"
          ]
        }
      ]
    }
  ],
  "resourceEntityTypeMap": {
    "Customers": "Customer:#MyApp",
    "Orders": "Order:#MyApp",
    "OrderItems": "OrderItem:#MyApp"
  }
}