public override Task <string[]> ObjectListAsync(string connectionString, string prefixText, Guid objectType, Authentication auth, DatasourceProperties properties)
{
return(Task.FromResult(new string[0]));
}
public override Task <bool> TestConnectionAsync(string connectionString, Authentication auth, DatasourceProperties properties)
{
return(Task.FromResult(true));
}
public override Task <DataTable> GetAvailableFilterFieldsAsync(string connectionString, Query query, Authentication auth, DatasourceProperties properties)
{
return(Task.FromResult(new DataTable()));
}
public async override Task <IDataReader> GetDataReaderAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
return((await GetDataAsync(connectionString, query, criteria, auth, properties)).CreateDataReader());
}
public override Task <DataTable> GetSchemaAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
// Schema requires all of the available fields be returned in a flattened structure. All levels are added
// as columns to the same DataTable. Nested field names must start with the same prefix as their parent column.
var data = new DataTable();
data.Columns.Add("Column1", typeof(int));
data.Columns.Add("ColumnNested", typeof(DataTable)); // A nested parent column is identified as being of type DataTable
data.Columns.Add("ColumnNested.ChildColumn", typeof(string));
return(Task.FromResult(data));
}
public override Task <DataTable> GetDataAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
// Data at the root level is constructed as normal. Only the fields relevant at this level are added.
var data = new DataTable();
data.Columns.Add("Column1", typeof(int));
data.Columns.Add("ColumnNested", typeof(DataTable));
data.BeginLoadData();
for (int i = 1; i < 3; i++)
{
DataRow currentRow = data.NewRow();
currentRow["Column1"] = i;
// Nested data is constructed as it's own DataTable and then inserted as the value of the
// cell in the parent row. This is typically implemented as recursive function calls to handle
// data at any level.
var nestedData = new DataTable();
nestedData.Columns.Add("ColumnNested.ChildColumn", typeof(string));
DataRow currentNestedRow = nestedData.NewRow();
currentNestedRow["ColumnNested.ChildColumn"] = "SubValue" + i.ToString();
nestedData.Rows.Add(currentNestedRow);
currentRow["ColumnNested"] = nestedData;
data.Rows.Add(currentRow);
}
data.EndLoadData();
return(Task.FromResult(data));
}
public override Task <DataTable> GetSchemaAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
// Returns all the available columns/fields of the service at 'connectionString', for the resource in 'query'
var data = new DataTable();
data.Columns.Add("Column1", typeof(int));
data.Columns.Add("Column2", typeof(string));
return(Task.FromResult(data));
}
public override Task <string[]> ObjectListAsync(string connectionString, string prefixText, Guid objectType, Authentication auth, DatasourceProperties properties)
{
// Return all the data objects in the service at 'connectionString', accessing the resource in 'query'
// Filter the results to those whose names begin with 'prefixText'
string[] availableObjects = { "SampleTable1", "SampleTable2" };
return(Task.FromResult(availableObjects.Where(s => s.StartsWith(prefixText, StringComparison.OrdinalIgnoreCase)).ToArray()));
}
public override Task <DataTable> GetDataAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
// Main function of a data source that is called whenever a form needs data from the external service.
// Connect to the service at 'connectionString', accessing the resource in 'query', matching the filters in 'criteria', using the credentials in 'auth'
var data = new DataTable();
data.Columns.Add("Column1", typeof(int));
data.Columns.Add("Column2", typeof(string));
data.BeginLoadData();
DataRow currentRow = data.NewRow();
currentRow["Column1"] = 123;
currentRow["Column2"] = "ABC";
data.Rows.Add(currentRow);
data.EndLoadData();
return(Task.FromResult(data));
}
public async override Task <IDataReader> GetDataReaderAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
// This GetData call is used when repeating documents are being created. To support a large number of rows a streaming DataReader is requested.
// If the service can't support that, create a DataReader wrapper from a DataTable.
return((await GetDataAsync(connectionString, query, criteria, auth, properties)).CreateDataReader());
}
public override Task <DataTable> GetAvailableFilterFieldsAsync(string connectionString, Query query, Authentication auth, DatasourceProperties properties)
{
// Return all the things that designers can use to limit the result in a call to GetDataAsync. For data bases this is typically column names, for
// web APIs - parameter names, etc.
// Forms the basis of what can be passed in the 'criteria' parameter when getting data.
var filterFields = new DataTable();
filterFields.Columns.Add("Filter1", typeof(int));
filterFields.Columns.Add("Filter2", typeof(string));
return(Task.FromResult(filterFields));
}
public override Task <bool> TestConnectionAsync(string connectionString, Authentication auth, DatasourceProperties properties)
{
// Test that a connection to the service in 'connectionString' can be made using the credentials in 'auth';
return(Task.FromResult(true));
}
public override Task <DataTable> GetSchemaAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
var data = new DataTable();
data.Columns.Add("Column1", typeof(string));
return(Task.FromResult(data));
}
public override Task <DataTable> GetDataAsync(string connectionString, Query query, DataFilter criteria, Authentication auth, DatasourceProperties properties)
{
var data = new DataTable();
data.Columns.Add("Column1", typeof(string));
data.BeginLoadData();
DataRow currentRow = data.NewRow();
currentRow["Column1"] = "ABC";
data.Rows.Add(currentRow);
data.EndLoadData();
if (criteria != null)
{
BuildFilteringStatementRecursive(criteria);
// Implementation Detail: Filter data with the filtering statement build from BuildFilteringStatementRecursive
}
return(Task.FromResult(data));
}
public override Task <DataTable> GetAvailableFilterFieldsAsync(string connectionString, Query query, Authentication auth, DatasourceProperties properties)
{
var filterFields = new DataTable();
filterFields.Columns.Add("Column1", typeof(string));
return(Task.FromResult(filterFields));
}
