ISynchronousDataRetriever::LoadChangeData
Retrieves item data for a change.
HRESULT LoadChangeData(
ILoadChangeContext * pLoadChangeContext,
IUnknown ** ppUnkData);
Parameters
- pLoadChangeContext
[in] Metadata that describes the change for which data should be retrieved.
- ppUnkData
[out] Returns the item data for the change specified in pLoadChangeContext.
Return Value
S_OK
Provider-determined error codes
Remarks
The source provider determines the data retrieval interface that is implemented by the object that is returned in ppUnkData. The destination provider can acquire this interface by using the QueryInterface method of ppUnkData.
Example
The following example is an implementation of LoadChangeData that finds the specified change in a custom data store and returns a copy of it.
STDMETHODIMP CItemStore::LoadChangeData(
ILoadChangeContext * pLoadChangeContext,
IUnknown ** ppUnkData)
{
HRESULT hr = E_UNEXPECTED;
if (NULL == pLoadChangeContext || NULL == ppUnkData)
{
hr = E_POINTER;
}
else
{
// Find the item in the data store, clone it, and return its IUnknown interface.
ISyncChange* pChange = NULL;
hr = pLoadChangeContext->GetSyncChange(&pChange);
if (SUCCEEDED(hr))
{
SYNC_GID gidItem;
DWORD cbID = sizeof(gidItem);
hr = pChange->GetRootItemId((BYTE*)&gidItem, &cbID);
if (SUCCEEDED(hr))
{
IXMLDOMNode* pNodeItem = NULL;
hr = FindItem(&gidItem, &pNodeItem);
if (SUCCEEDED(hr))
{
IXMLDOMNode* pNodeClone = NULL;
hr = pNodeItem->cloneNode(TRUE, &pNodeClone);
if (SUCCEEDED(hr))
{
hr = pNodeClone->QueryInterface(IID_IUnknown, (void**)ppUnkData);
pNodeClone->Release();
}
pNodeItem->Release();
}
}
pChange->Release();
}
}
return hr;
}