C: XML, Atom 1.0: Return Hierarchical Parent Resources: Listing 1

• 04/23/2008

The Atom 1.0 specification allows you to nest a <feed> group within <entry> groups to create a hierarchical structure that accommodates one-to-many associations. This Atom document's parent <feed> group for the Orders EntitySet contains an <entry> for each Order entity, which in turn contains an Order_Details <feed> group with <entry> groups for each Order_Detail entity. Atom <link> elements with an "edit" rel value specify an editable entity instance, and "related" indicates an associated entity or collection. A type attribute value of "entry" indicates a many-to-one or one-to-one EntityReference, and "feed" indicates a one-to-many EntitySet association.

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<feed xml:base=
"http://localhost:52660/Northwind.svc/" 
xmlns:ads="http://schemas.microsoft.com/ado/2007/08/
   dataweb" 
xmlns:adsm="http://schemas.microsoft.com/ado/2007/08/dataweb/
metadata" xmlns="http://www.w3.org/2005/Atom">
   <id>http://localhost:52660/Northwind.svc/Orders</id>
   <updated />
   <title>Orders</title>
   <link rel="self" href="Orders" title="Orders" />
   <entry adsm:type="NorthwindModel.Order">
      <id>http://localhost:52660/Northwind.svc/Orders(
      10248)</id>
      <updated />
      <title />
      <author>
         <name />
      </author>
      <link rel="edit" href="Orders(10248)" title=
      "Order" />
      <content type="application/xml">
         <ads:OrderID adsm:type="Int32">10248
         </ads:OrderID>
         <ads:OrderDate adsm:type="DateTime">
             1996-07-04T00:00:00
               </ads:OrderDate>
         <ads:RequiredDate adsm:type="DateTime">
               1996-08-01T00:00:00
               </ads:RequiredDate>
         <ads:ShippedDate adsm:type=
         "Nullable'1[System.DateTime]">
             1996-07-16T00:00:00
               </ads:ShippedDate>
         <ads:Freight adsm:type=
         "Nullable'1[System.Decimal]">
               32.3800
               </ads:Freight>
         <ads:ShipName>Vins et alcools Chevalier
         </ads:ShipName>
         <ads:ShipAddress>59 rue de l'Abbaye
         </ads:ShipAddress>
         <ads:ShipCity>Reims</ads:ShipCity>
         <ads:ShipRegion ads:null="true" />
         <ads:ShipPostalCode>51100</ads:ShipPostalCode>
         <ads:ShipCountry>France</ads:ShipCountry>
      </content>
      <link rel="related" title="Customer" 
         href="Orders(10248)/Customer" 
         type="application/atom+xml;type=entry" />
      <link rel="related" title="Employee" 
         href="Orders(10248)/Employee"    
         type="application/atom+xml;type=entry" />
      <link rel="related" title="Order_Details" 
          href="Orders(10248)/Order_Details"             adsm:inline="true" 
         type="application/atom+xml;type=feed">
         <feed>
            <id>http://localhost:52660/Northwind.svc/
             Orders(10248)/Order_Details</id>
            <updated />
            <title>Order_Details</title>
            <link rel="self" href="Orders(10248)/
            Order_Details" 
               title="Order_Details" />
            <entry adsm:type="NorthwindModel.Order_Detail">
               <id>http://localhost:52660/Northwind.svc/
                  Order_Details(10248,11)</id>
               <updated />
               <title />
               <author>
                  <name />
               </author>
               <link rel="edit" href="Order_Details(10248,11)" 
                  title="Order_Detail" />
               <content type="application/xml">
                  <ads:OrderID adsm:type="Int32">
                  10248</ads:OrderID>
                  <ads:ProductID adsm:type="Int32">
                  11   </ads:ProductID>
                  <ads:UnitPrice adsm:type="Decimal">
                         14.0000</ads:UnitPrice>
                  <ads:Quantity adsm:type="Int16">
                  12   </ads:Quantity>
                  <ads:Discount adsm:type="Single">
                  0</ads:Discount>
               </content>
               
            <link rel="related" title="Order" 
                  href="Order_Details(10248,11)/Order" 
                  type="application/atom+xml;type=entry" />
               <link rel="related" title="Product" 
                  href="Order_Details(10248,11)/Product" 
                  type="application/atom+xml;type=entry" />
            </entry>
            
            <!-- Additional Order_Details in nested <feed>
               groups ... -->
         </feed>
      </link>
      <link rel="related" title="Shipper"             href="Orders(10248)/Shipper" 
          type="application/atom+xml;type=entry" />   
   </entry>
   <!-- Additional Order entities in outer <entry> 
            groups ... -->

</feed>