vcl-dxbackend-dot-connectionstring-dot-json-dot-dataset-dot-tdxbackenddatasetjsonconnection-f184876c.md
Provides access to the backend dataset collection.
property DataSets: TdxBackendDataSetCollection read; write;
| Type | Description |
|---|---|
| TdxBackendDataSetCollection |
A backend dataset collection.
|
Each backend dataset item in the DataSets collection allows you to use a dataset (a TDataSet descendant instance) as a data source for a backend client component.
The TdxBackendDataSetJSONConnection component serializes content from source datasets and stores it in memory in the JSON format. You can use the ConnectionString property to access serialized data (if required).
Call the DataSets.Add method to create a new dataset item as demonstrated in the following code example: Load and Populate Report Templates from Datasets.
Refer to the TdxBackendDataSetCollection class description for detailed information on all available options.
This code example loads an XML-based report template (REPX) from a dataset, configures export settings, populates the template with data from another dataset, and displays the report preview:
uses
dxReport, // Declares the TdxReport component and related types
dxBackend.ConnectionString.JSON.DataSet; // Declares the TdxBackendDataSetJSONConnection component
// ...
procedure TMyForm.Button1Click(Sender: TObject);
var
ADataConnection: TdxBackendDataSetJSONConnection;
AReport: TdxReport;
ALayoutStream: TStream;
begin
ADataConnection := TdxBackendDataSetJSONConnection.Create(Self);
try
ADataConnection.Name := 'DataSetJSONData';
ADataConnection.DataSets.Add('Data', FDataSource);
AReport := TdxReport.Create(Self);
try
AReport.ReportName := 'Report';
ALayoutStream := FLayoutDataSet.CreateBlobStream(FLayoutDataSet.FieldByName('Layout'), bmRead);
try
AReport.Layout.LoadFromStream(ALayoutStream);
finally
ALayoutStream.Free;
end;
AReport.Language := 'fr-FR';
AReport.ExportFormats := [TdxReportExportFormat.PDF,
TdxReportExportFormat.RTF, TdxReportExportFormat.HTML];
AReport.FilterString := 'id = 5';
AReport.ShowViewer;
finally
AReport.Free;
end;
finally
ADataConnection.Free;
end;
end;
#include "dxReport.hpp" // Declares the TdxReport component and related types
#include "dxBackend.ConnectionString.JSON.DataSet.hpp" // Declares the TdxBackendDataSetJSONConnection component
// Add the following linker directives to the corresponding CPP source file:
#pragma link "dxReport" // Required to use dxReport.hpp declarations
#pragma link "dxBackend.ConnectionString.JSON.DataSet" //Required to use TdxBackendDataSetJSONConnection declarations
// ...
void __fastcall TMyForm::Button1Click(TObject *Sender)
{
TdxBackendDataSetJSONConnection *ADataConnection;
TdxReport *AReport;
TStream *ALayoutStream;
ADataConnection = new TdxBackendDataSetJSONConnection(this);
try
{
ADataConnection->Name = "DataSetJSONData";
ADataConnection->DataSets->Add("Data", FDataSource);
AReport = new TdxReport(this);
try
{
AReport->ReportName = "Report";
ALayoutStream = FLayoutDataSet->CreateBlobStream(FLayoutDataSet->FieldByName("Layout"), bmRead);
try
{
AReport->Layout->LoadFromStream(ALayoutStream);
}
__finally
{
delete ALayoutStream;
}
AReport->Language = "fr-FR";
AReport->ExportFormats = TdxReportExportFormats() << TdxReportExportFormat::PDF
<< TdxReportExportFormat::RTF << TdxReportExportFormat::HTML;
AReport->FilterString = "id = 5";
AReport->ShowViewer();
}
__finally
{
delete AReport;
}
}
__finally
{
delete ADataConnection;
}
}
See Also
TdxBackendDataSetJSONConnection.AutoRefreshData Property
TdxBackendCustomInMemoryJSONConnection.ConnectionString Property
TdxBackendDataSetJSONConnection Class