Pascal (Lazarus/Delphi)

Serialize / Deserialize Hashtable to/from XML

Demonstrates how to seralize / deserialize a Hashtable to/from XML.

Note: This example requires Chilkat v9.5.0.64 or later.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.StringTable,
  Chilkat.StringBuilder,
  Chilkat.Hashtable;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  hashTab: THashtable;
  sb: TStringBuilder;
  hashTab2: THashtable;
  sTable: TStringTable;
  i: Integer;
  numKeys: Integer;
  key: string;

begin
  //  Note: This example requires Chilkat v9.5.0.64 or later.

  //  Add some entries to a hashtable.
  hashTab := THashtable.Create;

  hashTab.AddStr('aaa','111');
  hashTab.AddStr('bbb','222');
  hashTab.AddStr('ccc','333');

  //  Serialize to XML
  sb := TStringBuilder.Create;
  hashTab.ToXmlSb(sb);
  WriteLn(sb.GetAsString());
  WriteLn('---');

  //  The output is as follows.  Each hash table entry
  //  is contained in an "e" node.  The entry's key
  //  is in the "k" node, and the value in the "v" node.

  //  <?xml version="1.0" encoding="utf8-8"?>
  //  <hashtable>
  //  <e><k>aaa</k><v>111</v></e>
  //  <e><k>bbb</k><v>222</v></e>
  //  <e><k>ccc</k><v>333</v></e>
  //  </hashtable>
  //  

  //  Now load (deserialize) into a new hash table.
  hashTab2 := THashtable.Create;
  hashTab2.AddFromXmlSb(sb);

  //  Get the hash table keys, and lookup each (to show 
  //  that the hash table was correctly deserialized).
  //  The GetKeys method can return the keys in any order.
  sTable := TStringTable.Create;
  hashTab2.GetKeys(sTable);

  i := 0;
  numKeys := sTable.Count;
  while i < numKeys do
    begin
      key := sTable.StringAt(i);
      WriteLn(key + ': ' + hashTab2.LookupStr(key));
      i := i + 1;
    end;



  hashTab.Free;
  sb.Free;
  hashTab2.Free;
  sTable.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.