Delphi DLL

Keeping Query Params in a Hashtable

Demonstrates how to use a Chilkat Hashtable to hold query params and re-emit as a query param string.

Note: The ToQueryString method was added in Chilkat v9.5.0.92.

Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Hashtable, StringTable;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
ht: HCkHashtable;
qp: PWideChar;
keys: HCkStringTable;
numKeys: Integer;
key: PWideChar;
val: PWideChar;
i: Integer;

begin
success := False;

ht := CkHashtable_Create();

// Add name/value pairs from an existing query param string where the values are already URL encoded.
qp := 'txt=this%20is%20a%20test&color=blue&fruits=apples%26oranges';
success := CkHashtable_AddQueryParams(ht,qp);

// Add some additional name/value pairs.
CkHashtable_AddStr(ht,'name','Jack Sparrow');
CkHashtable_AddStr(ht,'movie','Pirates of the Carribean');

// Iterate over the hash table to show what we have..

keys := CkStringTable_Create();
CkHashtable_GetKeys(ht,keys);
numKeys := CkStringTable_getCount(keys);

i := 0;
while i < numKeys do
  begin
    key := CkStringTable__stringAt(keys,i);
    val := CkHashtable__lookupStr(ht,key);
    Memo1.Lines.Add(key + ' = ' + val);
    i := i + 1;
  end;

// Output for the above loop:

// color = blue
// name = Jack Sparrow
// fruits = apples&oranges
// txt = this is a test
// movie = Pirates of the Carribean

// Get all name/value pairs as a query parm string with values URL encoded
qp := CkHashtable__toQueryString(ht);
Memo1.Lines.Add(qp);

// Result:
// color=blue&name=Jack%20Sparrow&fruits=apples%26oranges&txt=this%20is%20a%20test&movie=Pirates%20of%20the%20Carribean

CkHashtable_Dispose(ht);
CkStringTable_Dispose(keys);

end;