public class ODataVirtualDataSourceDataProvider
: IDataSourceVirtualDataProvider
{
private ODataVirtualDataSourceDataProviderWorker _worker;
private LinkedList<int> _requests = new LinkedList<int>();
private DataSourcePageLoadedCallback _callback;
public ODataVirtualDataSourceDataProvider()
{
_sortDescriptions = new SortDescriptionCollection();
_sortDescriptions.CollectionChanged += SortDescriptions_CollectionChanged;
_filterExpressions = new FilterExpressionCollection();
_filterExpressions.CollectionChanged += FilterExpressions_CollectionChanged;
_groupDescriptions = new SortDescriptionCollection();
_groupDescriptions.CollectionChanged += GroupDescriptions_CollectionChanged;
_summaryDescriptions = new SummaryDescriptionCollection();
_summaryDescriptions.CollectionChanged += _summaryDescriptions_CollectionChanged;
}
private void _summaryDescriptions_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
QueueAutoRefresh();
}
private void FilterExpressions_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
QueueAutoRefresh();
}
private void SortDescriptions_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
QueueAutoRefresh();
}
private void GroupDescriptions_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
QueueAutoRefresh();
}
public void AddPageRequest(int pageIndex, DataSourcePageRequestPriority priority)
{
if (DeferAutoRefresh)
{
return;
}
if (_worker != null && _worker.IsShutdown)
{
_worker = null;
_callback = null;
}
if (_worker == null)
{
CreateWorker();
}
if (priority == DataSourcePageRequestPriority.High)
{
_requests.AddFirst(pageIndex);
}
else
{
_requests.AddLast(pageIndex);
}
if (!_worker.AddPageRequest(pageIndex, priority))
{
_worker = null;
_callback = null;
AddPageRequest(pageIndex, priority);
}
}
private void CreateWorker()
{
if (!Valid())
{
return;
}
_callback = RaisePageLoaded;
var settings = GetWorkerSettings();
_worker = new ODataVirtualDataSourceDataProviderWorker(settings);
}
private bool Valid()
{
return EntitySet != null &&
BaseUri != null;
}
private ODataVirtualDataSourceDataProviderWorkerSettings GetWorkerSettings()
{
return new ODataVirtualDataSourceDataProviderWorkerSettings()
{
BaseUri = _baseUri,
EntitySet = _entitySet,
PageSizeRequested = _pageSizeRequested,
TimeoutMilliseconds = _timeoutMilliseconds,
PageLoaded = _callback,
ExecutionContext = _executionContext,
SortDescriptions = _sortDescriptions,
FilterExpressions = _filterExpressions,
PropertiesRequested = _propertiesRequested,
GroupDescriptions = _groupDescriptions,
IsAggregationSupportedByServer = _isAggregationSupportedByServer,
SummaryDescriptions = _summaryDescriptions,
SummaryScope = _summaryScope
};
}
public void RemovePageRequest(int pageIndex)
{
_requests.Remove(pageIndex);
if (_worker == null)
{
return;
}
_worker.RemovePageRequest(pageIndex);
}
public void RemoveAllPageRequests()
{
_requests.Clear();
if (_worker == null)
{
return;
}
_worker.RemoveAllPageRequests();
}
public void Close()
{
if (_worker != null)
{
_worker.Shutdown();
_worker = null;
_callback = null;
}
}
private DataSourcePageLoadedCallback _pageLoaded;
public DataSourcePageLoadedCallback PageLoaded
{
get
{
return _pageLoaded;
}
set
{
_pageLoaded = value;
QueueAutoRefresh();
}
}
private void RaisePageLoaded(IDataSourcePage page, int fullCount, int actualPageSize)
{
if (_pageLoaded != null)
{
_currentFullCount = fullCount;
if (_currentSchema == null)
{
IDataSourceSchema currentSchema = null;
if (page != null)
{
currentSchema = page.Schema();
}
_currentSchema = currentSchema;
if (SchemaChanged != null)
{
SchemaChanged(this, new DataSourceDataProviderSchemaChangedEventArgs(_currentSchema, _currentFullCount));
}
}
if (page.PageIndex() != ODataVirtualDataSourceDataProviderWorker.SchemaRequestIndex)
{
_pageLoaded(page, fullCount, actualPageSize);
}
}
}
private void KillWorker()
{
if (_worker != null)
{
_worker.Shutdown();
_worker = null;
_callback = null;
}
}
private int _pageSizeRequested = 50;
public int PageSizeRequested
{
get
{
return _pageSizeRequested;
}
set
{
_pageSizeRequested = value;
QueueAutoRefresh();
}
}
private string _baseUri = null;
public string BaseUri
{
get
{
return _baseUri;
}
set
{
var oldValue = _baseUri;
_baseUri = value;
if (oldValue != _baseUri)
{
QueueAutoRefresh();
if (Valid() && DeferAutoRefresh)
{
QueueSchemaFetch();
}
}
}
}
private string _entitySet = null;
public string EntitySet
{
get
{
return _entitySet;
}
set
{
var oldValue = _entitySet;
_entitySet = value;
if (oldValue != _entitySet)
{
QueueAutoRefresh();
if (Valid() && DeferAutoRefresh)
{
QueueSchemaFetch();
}
}
}
}
private int _timeoutMilliseconds = 10000;
public int TimeoutMilliseconds
{
get
{
return _timeoutMilliseconds;
}
set
{
_timeoutMilliseconds = value;
QueueAutoRefresh();
}
}
private bool _isAggregationSupportedByServer = false;
/// <summary>
/// Gets or sets whether the server supports aggregation query options required for grouping.
/// </summary>
public bool IsAggregationSupportedByServer
{
get
{
return _isAggregationSupportedByServer;
}
set
{
var oldValue = _isAggregationSupportedByServer;
_isAggregationSupportedByServer = value;
QueueAutoRefresh();
}
}
public object GetItemValue(object item, string valueName)
{
var dic = (IDictionary<string, object>)item;
if (dic.ContainsKey(valueName))
{
return dic[valueName];
}
else
{
return null;
}
}
public event DataSourceDataProviderSchemaChangedHandler SchemaChanged;
private int _currentFullCount = 0;
private IDataSourceSchema _currentSchema;
public int ActualCount
{
get
{
return _currentFullCount;
}
}
public IDataSourceSchema ActualSchema
{
get
{
return _currentSchema;
}
}
private IDataSourceExecutionContext _executionContext;
public IDataSourceExecutionContext ExecutionContext
{
get
{
return _executionContext;
}
set
{
_executionContext = value;
QueueAutoRefresh();
}
}
private IDataSourceDataProviderUpdateNotifier _updateNotifier;
public IDataSourceDataProviderUpdateNotifier UpdateNotifier
{
get
{
return _updateNotifier;
}
set
{
_updateNotifier = value;
}
}
private bool _deferAutoRefresh = false;
public bool DeferAutoRefresh
{
get
{
return _deferAutoRefresh;
}
set
{
_deferAutoRefresh = value;
if (!_deferAutoRefresh)
{
QueueAutoRefresh();
}
if (_deferAutoRefresh && Valid() && _currentSchema == null)
{
QueueSchemaFetch();
}
}
}
public bool IsSortingSupported
{
get
{
return true;
}
}
public bool IsFilteringSupported
{
get
{
return true;
}
}
private SortDescriptionCollection _sortDescriptions;
public SortDescriptionCollection SortDescriptions
{
get
{
return _sortDescriptions;
}
}
private string[] _propertiesRequested;
public string[] PropertiesRequested
{
get
{
return _propertiesRequested;
}
set
{
_propertiesRequested = value;
QueueAutoRefresh();
}
}
private FilterExpressionCollection _filterExpressions;
public FilterExpressionCollection FilterExpressions
{
get
{
return _filterExpressions;
}
}
public bool NotifyUsingSourceIndexes
{
get
{
return true;
}
}
public bool IsItemIndexLookupSupported
{
get
{
return false;
}
}
public bool IsKeyIndexLookupSupported
{
get
{
return false;
}
}
public bool IsGroupingSupported
{
get
{
return false;
}
}
private SortDescriptionCollection _groupDescriptions;
public SortDescriptionCollection GroupDescriptions
{
get
{
return _groupDescriptions;
}
}
private SummaryDescriptionCollection _summaryDescriptions;
public SummaryDescriptionCollection SummaryDescriptions
{
get
{
return _summaryDescriptions;
}
}
private DataSourceSummaryScope _summaryScope;
public DataSourceSummaryScope SummaryScope
{
get
{
return _summaryScope;
}
set
{
_summaryScope = value;
}
}
public void NotifySetItem(int index, object oldItem, object newItem)
{
if (UpdateNotifier != null)
{
UpdateNotifier.NotifySetItem(index, oldItem, newItem);
}
}
public void NotifyClearItems()
{
if (UpdateNotifier != null)
{
UpdateNotifier.NotifyClearItems();
}
}
public void NotifyInsertItem(int index, object newItem)
{
if (UpdateNotifier != null)
{
UpdateNotifier.NotifyInsertItem(index, newItem);
}
}
public void NotifyRemoveItem(int index, object oldItem)
{
if (UpdateNotifier != null)
{
UpdateNotifier.NotifyRemoveItem(index, oldItem);
}
}
internal bool _schemaFetchQueued = false;
public void QueueSchemaFetch()
{
if (_schemaFetchQueued)
{
return;
}
if (ExecutionContext != null)
{
_schemaFetchQueued = true;
ExecutionContext.EnqueueAction(DoSchemaFetchInternal);
}
}
internal void DoSchemaFetchInternal()
{
if (!_schemaFetchQueued)
{
return;
}
_schemaFetchQueued = false;
SchemaFetchInternal();
}
internal void SchemaFetchInternal()
{
SchemaFetchInternalOverride();
}
protected virtual void SchemaFetchInternalOverride()
{
if (!DeferAutoRefresh)
{
return;
}
RemoveAllPageRequests();
KillWorker();
CreateWorker();
AddSchemaRequest();
}
private void AddSchemaRequest()
{
_worker.AddPageRequest(
ODataVirtualDataSourceDataProviderWorker.SchemaRequestIndex,
DataSourcePageRequestPriority.High
);
}
internal bool _autoRefreshQueued = false;
public void QueueAutoRefresh()
{
if (DeferAutoRefresh)
{
return;
}
if (_autoRefreshQueued)
{
return;
}
if (ExecutionContext != null)
{
_autoRefreshQueued = true;
ExecutionContext.EnqueueAction(DoRefreshInternal);
}
}
internal void DoRefreshInternal()
{
if (DeferAutoRefresh)
{
_autoRefreshQueued = false;
return;
}
if (!_autoRefreshQueued)
{
return;
}
_autoRefreshQueued = false;
RefreshInternal();
}
internal void RefreshInternal()
{
RefreshInternalOverride();
}
protected virtual void RefreshInternalOverride()
{
RemoveAllPageRequests();
KillWorker();
CreateWorker();
//TODO: should we have this here? prob need to readd request for current page instead.
_worker.AddPageRequest(0, DataSourcePageRequestPriority.Normal);
}
public void FlushAutoRefresh()
{
DoRefreshInternal();
}
public void Refresh()
{
RefreshInternal();
}
public int IndexOfItem(object item)
{
return -1;
}
public int IndexOfKey(object[] key)
{
return -1;
}
public DataSourceSchemaPropertyType ResolveSchemaPropertyType(string propertyPath)
{
var propertiesInPath = propertyPath.Split('.');
if (propertiesInPath.Length == 1 && this.ActualSchema != null)
{
for (int i = 0; i < this.ActualSchema.PropertyNames.Length; i++)
{
if (this.ActualSchema.PropertyNames[i] == propertiesInPath[0])
{
return this.ActualSchema.PropertyTypes[i];
}
}
}
return DataSourceSchemaPropertyType.ObjectValue;
}
}
