TdxReportInMemoryJSONConnection Class

A component designed for interaction with data stored in memory.

Declaration

TdxReportInMemoryJSONConnection = class(
    TdxReportCustomInMemoryJSONConnection
)

Remarks

A data connection component allows you to bind a TdxReport component to data.

Main API Members

The list below outlines key members of the TdxReportInMemoryJSONConnection class. These members allow you to configure core data connection settings.

Data Connection Settings

Active: Specifies if the data connection is active.
DisplayName: Specifies the data connection’s name in both Report Designer and Collection Editor dialogs.
ConnectionString: Specifies a connection string or source data (as a string in the JSON format).

Tip
Refer to the following topic for detailed information on JSON Data: Connection to a JSON Data Source.

General-Purpose API Members

Collection | Index: Specify the parent collection component.

Code Example: Generate Reports Based on In-Memory Data

The following code example loads an XML-based report template (TdxReport.Layout) from a REPX file, populates the template with test data defined in a connection string, and exports the resulting report as a PNG image:

Delphi
C++

uses
  dxReport,  // Declares the TdxReport component and related types
  dxReport.ConnectionString.JSON;  // Declares the TdxReportInMemoryJSONConnection component
// ...

procedure TMyForm.Button1Click(Sender: TObject);
var
  AJSONDataConnection: TdxReportInMemoryJSONConnection;
  AReport: TdxReport;
  AFileStream: TFileStream;
begin
  AJSONDataConnection := TdxReportInMemoryJSONConnection.Create(Self);
  try
    AJSONDataConnection.Name := 'JSONData';
    // Specify in-memory report data as a connection string
    AJSONDataConnection.ConnectionString :=
      'Json=''[{"id":1, "caption":"test1"},{"id":2, "caption":"test2"}]''';
    AReport := TdxReport.Create(Self);
    try
      AReport.ReportName := 'Report';
      AReport.Layout.LoadFromFile('Report.repx');  // Loads a report template
      AFileStream := TFileStream.Create('Report.png', fmOpenReadWrite);
      try
        AReport.ExportToImage(AFileStream);  // Exports the report in the default image export format (PNG)
      finally
        AFileStream.Free;
      end;
    finally
      AReport.Free;
    end;
  finally
    AJSONDataConnection.Free;
  end;
end;

#include "dxReport.hpp"  // Declares the TdxReport component
#include "dxReport.ConnectionString.JSON.hpp"  // Declares the TdxReportInMemoryJSONConnection component

// Add the following linker directives to the corresponding CPP source file:
#pragma link "dxReport"  // Required for dxReport.hpp declarations
#pragma link "dxReport.ConnectionString.JSON" // Required for dxReport.ConnectionString.JSON.hpp declarations
// ...

void __fastcall TMyForm::Button1Click(TObject *Sender)
{
  TdxReportInMemoryJSONConnection *AJSONDataConnection;
  TdxReport *AReport;
  TFileStream *AFileStream;
  AJSONDataConnection = new TdxReportInMemoryJSONConnection(this);
  try
  {
    AJSONDataConnection->Name = "JSONData";
    // Specify in-memory report data as a connection string
    AJSONDataConnection->ConnectionString =
      "Json=\"\"[{\"id\":1, \"caption\":\"test1\"}, {\"id\":2, \"caption\":\"test2\"}]\"";
    AReport = new TdxReport(this);
    try
    {
      AReport->ReportName = "Report";
      AReport->Layout->LoadFromFile("Report.repx");  // Loads a report template
      AFileStream = new TFileStream('Report.png', fmOpenReadWrite);
      try
      {
        AReport->ExportToImage(AFileStream);  // Exports the report in the default image export format (PNG)
      }
      __finally
      {
        delete AFileStream;
      }
    }
    __finally
    {
        delete AReport;
    }
  }
  __finally
  {
    delete AJSONDataConnection;
  }
}

Indirect TdxReportInMemoryJSONConnection Class References

The following public API members reference the TdxReportInMemoryJSONConnection class as a TdxReportCustomDataConnection object:

TdxReportDataConnectionCollection.Add: Creates a data connection of the required type and adds the connection to the collection.
TdxReportDataConnectionCollection.Items: Provides indexed access to all data connection components stored in the collection.
TdxReportDataConnectionManager.Items: Provides indexed access to stored data connection components.

Other Report Data Connection Components

TdxReportDataSetJSONConnection: A component designed to fetch data from one or multiple datasets (TDataSet descendant instances).
TdxReportDatabaseSQLConnection: A component designed to fetch data from an SQL database (SQL Server, PostgreSQL, SQLite, etc.).