TdxReportCustomInMemoryJSONConnection.ConnectionString Property

Specifies a connection string or stores serialized data (in the JSON format).

Declaration

property ConnectionString: string read; write;

Property Value

Type	Description
string	The connection string or serialized data in the JSON format.

Remarks

The ConnectionString property serves different purposes for TdxReportInMemoryJSONConnection and TdxReportDataSetJSONConnection components (TdxReportCustomInMemoryJSONConnection descendants).

In-Memory JSON Connection Component

ConnectionString is the main property^[1] in the TdxReportInMemoryJSONConnection class. You can use this property to:

• Specify required data as a JSON string (as demonstrated in the code example below).

• Specify a Web Service Endpoint URL or a path to the required JSON file. For example:

  'Uri=https://northwind.netcore.io/customers.json;Username=user; Password=pwd; header:MyAuthHedaer1=secretToken1; header:MyAuthHeader2=secretToken2; query:id=123456;query=name=MyName'

  Tip

  Refer to the following topic for detailed information in this regard: JSON Data.

Dataset-Based JSON Connection Component

The ConnectionString property stores serialized JSON data from datasets associated with a TdxReportDataSetJSONConnection component. Use the DataSets property to bind and configure one or multiple datasets (TdxMemData, TFDTable, TFDQuery, etc.).

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

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;

C++

#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;
  }
}

Default Value

The ConnectionString property’s default value is an empty string.

Footnotes

1. Available in the Object Inspector.