/// <summary>
/// Runs a test query against the specified date field to determine the type of data source.
/// </summary>
private static void QueryDate(string dataSetUrl, bool useProxy, SubLayerField dateField, string dataSource, EventHandler <DataSourceEventArgs> callback)
{
DateTime testDate = new DateTime(1977, 12, 01, 0, 0, 0, 0);
QueryTask qT = new QueryTask(dataSetUrl);
if (useProxy)
{
qT.ProxyURL = ArcGISOnlineEnvironment.ConfigurationUrls.ProxyServerEncoded;
}
ESRI.ArcGIS.Client.Tasks.Query q = new ESRI.ArcGIS.Client.Tasks.Query();
q.OutFields.Add(dateField.Name);
q.Where = dateField.Name + " = " + Format(testDate, dataSource);
q.ReturnGeometry = false;
EventHandler <ESRI.ArcGIS.Client.Tasks.QueryEventArgs> completedHandler = null;
completedHandler = (object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs e) =>
{
callback(null, new DataSourceEventArgs()
{
DataSource = dataSource
});
};
qT.ExecuteCompleted += completedHandler;
//execute the query
//
qT.ExecuteAsync(q);
}
/// <summary>
/// Determines the data source type asynchronously from a date field by running a series of test queries against it.
/// </summary>
/// <remarks>
/// If a test query succeeds the data source type is reported back to the client via the callback. It is possible that
/// multiple queries succeed so the client is called back multiple times.
/// </remarks>
/// <param name="dataSetUrl">The data set that contains the dateField.</param>
/// <param name="dateField">A date field used to determine the data source type.</param>
/// <param name="callback">A event handler that is called back when a test query succeeds. Multiple callbacks are possible.</param>
public static void GetDataSource(string dataSetUrl, bool useProxy, SubLayerField dateField, EventHandler <DataSourceEventArgs> callback)
{
foreach (string dataSource in SupportedDataSources)
{
QueryDate(dataSetUrl, useProxy, dateField, dataSource, callback);
}
}
/// <summary>
/// Occurs when a field is selected. Adds the field to the where clause then
/// clears the FieldListBox selection.
/// </summary>
internal void FieldListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
SubLayerField field = FieldListBox.SelectedItem as SubLayerField;
if (field != null)
{
AddText(field.Name);
}
FieldListBox.SelectedItem = null;
}
/// <summary>
/// If the feature layer contains fields of type Date, runs a sequence of test queries to determine
/// the date format required by the underlying data source.
/// </summary>
private void SetupDateFormat()
{
if (QueryProperties.SubLayerDescription.Fields == null)
{
return;
}
SubLayerField dateField = null;
foreach (SubLayerField field in QueryProperties.SubLayerDescription.Fields)
{
if (field.Type == "esriFieldTypeDate")
{
dateField = field;
break;
}
}
if (dateField == null)
{
return;
}
//get the data source type from the QueryDateHelper by running a series of test queries against the dateField
//
QueryDateHelper.GetDataSource(QueryProperties.SubLayerDescription.Url, QueryProperties.SubLayerDescription.RequiresProxy, dateField, (object sender, DataSourceEventArgs e) =>
{
//query succeeded -> cache the datasource so the correctly formatted dates can be
//generated when the expression is created
//
if (_dataSource == null)
{
_dataSource = e.DataSource;
}
else
{
//if data source has already been set check if this one has higher priority
//if yes - replace
//
List <string> supportedDS = new List <string>(QueryDateHelper.SupportedDataSources);
if (supportedDS.IndexOf(e.DataSource) < supportedDS.IndexOf(_dataSource))
{
_dataSource = e.DataSource;
}
}
ExpressionDatePickerButton.IsEnabled = true;
});
}
/// <summary>
/// Initializes the Data tab with a sample view of attributes of the layer.
/// </summary>
private void SetupPreview()
{
if (FeatureLayer == null)
{
return;
}
QueryTask qT = new QueryTask(FeatureLayer.Url);
qT.ProxyURL = FeatureLayer.ProxyUrl;
ESRI.ArcGIS.Client.Tasks.Query q = new ESRI.ArcGIS.Client.Tasks.Query();
foreach (var field in QueryProperties.SubLayerDescription.Fields)
{
q.OutFields.Add(field.Name);
}
q.Where = "1=1"; //query for features in the layer, todo: any way to limit the number of features returned?
q.ReturnGeometry = false;
EventHandler <ESRI.ArcGIS.Client.Tasks.QueryEventArgs> completedHandler = null;
EventHandler <TaskFailedEventArgs> failedHandler = null;
completedHandler = (object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs e) =>
{
PreviewDataGrid.Columns.Clear();
if (e.FeatureSet == null || e.FeatureSet.Features == null || e.FeatureSet.Features.Count == 0)
{
return;
}
//set up the columns of the table
//if a field does not exist in the layer description don't add it to the table
//this is the case for the geometry field
//
List <string> columns = new List <string>();
foreach (string key in e.FeatureSet.Features[0].Attributes.Keys)
{
if (GetField(key) != null)
{
columns.Add(key);
}
}
int count = 0;
Table table = new Table(columns.ToArray());
foreach (Graphic feature in e.FeatureSet)
{
List <object> cells = new List <object>();
foreach (var attribute in feature.Attributes)
{
SubLayerField field = GetField(attribute.Key);
if (field == null)
{
continue;
}
if (field.AttributeDomain != null && field.AttributeDomain.Type == "codedValue" && attribute.Value != null)
{
cells.Add(field.AttributeDomain[attribute.Value]);
}
else
{
//if the field value is a date in milliseconds format it to a user readable date
//
string formattedDateString = null;
if (field.Type == "esriFieldTypeDate" && attribute.Value != null && attribute.Value.ToString().TryParseToDateString(out formattedDateString))
{
cells.Add(formattedDateString);
}
else
{
cells.Add(attribute.Value);
}
}
}
table.Rows.Add(new Row(cells.ToArray()));
count++;
if (count == 25)
{
break;
}
}
//initialize the DataGrid columns
//
foreach (DataGridTextColumn column in table.Columns)
{
column.CanUserSort = true;
PreviewDataGrid.Columns.Add(column);
}
//setting the table as the DataContext of the DataGrid initializes the rows via binding
//
PreviewDataGrid.DataContext = table;
PreviewDataGrid.UpdateLayout();
if (table.Rows.Count > 0 && PreviewDataGrid.Columns.Count > 0)
{
PreviewDataGrid.ScrollIntoView(table.Rows[0].Cells[0], PreviewDataGrid.Columns[0]);
}
DataPreviewProgressIndicator.Visibility = Visibility.Collapsed;
};
failedHandler = ((object sender, TaskFailedEventArgs e) =>
{
FailedPreviewTextBlock.Visibility = Visibility.Visible;
DataPreviewProgressIndicator.Visibility = Visibility.Collapsed;
});
qT.ExecuteCompleted += completedHandler;
qT.Failed += failedHandler;
//execute the query
//
qT.ExecuteAsync(q);
}
/// <summary>
/// Runs a test query against the specified date field to determine the type of data source.
/// </summary>
private static void QueryDate(string dataSetUrl, bool useProxy, SubLayerField dateField, string dataSource, EventHandler<DataSourceEventArgs> callback)
{
DateTime testDate = new DateTime(1977, 12, 01, 0, 0, 0, 0);
QueryTask qT = new QueryTask(dataSetUrl);
if (useProxy)
qT.ProxyURL = ArcGISOnlineEnvironment.ConfigurationUrls.ProxyServerEncoded;
ESRI.ArcGIS.Client.Tasks.Query q = new ESRI.ArcGIS.Client.Tasks.Query();
q.OutFields.Add(dateField.Name);
q.Where = dateField.Name + " = " + Format(testDate, dataSource);
q.ReturnGeometry = false;
EventHandler<ESRI.ArcGIS.Client.Tasks.QueryEventArgs> completedHandler = null;
completedHandler = (object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs e) =>
{
callback(null, new DataSourceEventArgs() { DataSource = dataSource });
};
qT.ExecuteCompleted += completedHandler;
//execute the query
//
qT.ExecuteAsync(q);
}
/// <summary>
/// Determines the data source type asynchronously from a date field by running a series of test queries against it.
/// </summary>
/// <remarks>
/// If a test query succeeds the data source type is reported back to the client via the callback. It is possible that
/// multiple queries succeed so the client is called back multiple times.
/// </remarks>
/// <param name="dataSetUrl">The data set that contains the dateField.</param>
/// <param name="dateField">A date field used to determine the data source type.</param>
/// <param name="callback">A event handler that is called back when a test query succeeds. Multiple callbacks are possible.</param>
public static void GetDataSource(string dataSetUrl, bool useProxy, SubLayerField dateField, EventHandler<DataSourceEventArgs> callback)
{
foreach (string dataSource in SupportedDataSources)
QueryDate(dataSetUrl, useProxy, dateField, dataSource, callback);
}
