Using Batch support in Google Base

# The batch support

Release 1.0.5 includes support for the GoogleBatch protocol extensions. Refer to the code.google.com documentation for details on this in general.

In the C# libraries this is implemented as basic support on the AtomFeed and AtomEntry. Those objects have a new member, called BatchData. Setting this data controls the operations executed on the batchfeed, and this object also holds the return values for from the server.

To create a feed useful to talk to the batch service, you need to know the service URI for this. Here is a code snippet that retrieves that URI.

`FeedQuery query = new FeedQuery();
Service service = new Service("gbase", "mytestapplication");
NetworkCredential nc = new NetworkCredential(userName, passWord);
service.Credentials = nc;
// setup the google web key
GDataGAuthRequestFactory authFactory = service.RequestFactor as GDataGAuthRequestFactory;
authFactory.GoogleWebKey = "yourkey";
query.Uri = new Uri("http://base.google.com/base/feeds/items");
AtomFeed baseFeed = service.Query(query);
// this should have a batch URI
if (baseFeed.Batch != null) {
....`

Note, that to talk to GoogleBase, you also need a web developer key, you can see above that, once you have that key, you only need to set the GoogleWebKey property on the service to use it.

Now to set the default operation you want the batchfeed to do, you use code similiar to this:

`
batchFeed.BatchData = new GDataBatchFeedData();
batchFeed.BatchData.Type = GDataBatchOperationType.delete;`

If you do not set this, the feed will default to insert as it's operation type.

You would then go and add entries to your feed. If you want the entry to behave differently than the feed itself, you set the BatchData object on the entry.

`
entry.BatchData = new GDataBatchEntryData();
entry.BatchData.Type = GDataBatchOperationType.insert;
entry.BatchData.Id = "some id";`

To finally do the batch, you just call the new service method for this purpose:

`
AtomFeed resultFeed = service.Batch(batchFeed, new Uri(baseFeed.Batch));`

To verify that the operations were successfull, you need to iterate over the returned entries:

`
foreach (AtomEntry resultEntry in resultFeed.Entries )
{
GDataBatchEntryData data = resultEntry.BatchData;
switch (data.Stutus.Code) {
case 200:....
}
}`