Delphi ActiveX

Find and Delete Object from JSON Array

See more JSON Examples

Demonstrates how to find an delete an object from a JSON array of objects. Delphi ActiveX

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
json: TChilkatJsonObject;
menu: IChilkatJsonObject;
catArr: IChilkatJsonArray;
index: Integer;

begin
success := 0;

// This example will delete the "Pasta" category object from Menu B.

// {
//   "menus": [
//     {
//       "name": "Menu A",
//       "categories": [
// 			{
// 			"name": "Kebabs",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Burgers",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Pasta",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Appetizers",
// 			"description": "blah blah blah"
// 			}
// 		]
// 	},
//     {
//       "name": "Menu B",
//       "categories": [
// 			{
// 			"name": "Kebabs",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Burgers",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Pasta",
// 			"description": "blah blah blah"
// 			},
// 			{
// 			"name": "Appetizers",
// 			"description": "blah blah blah"
// 			}
// 		]
// 	  }
// 	]
// }

json := TChilkatJsonObject.Create(Self);
success := json.LoadFile('qa_data/json/menus.json');
if (success = 0) then
  begin
    Memo1.Lines.Add(json.LastErrorText);
    Exit;
  end;

// Find Menu B.
menu := json.FindRecord('menus','name','Menu B',1);
// assume menu is found..

// Get the categories array, and then find the index of the "Pasta" menu category.
catArr := menu.ArrayOf('categories');
// Assume it is found..

// Find the object where the name of the JSON member is "name", and the value is "Pasta"
index := catArr.FindObject('name','Pasta',1);
if (index < 0) then
  begin
    Memo1.Lines.Add('Pasta not found.');
  end
else
  begin

    // Delete the "Pasta" category record from Menu B
    success := catArr.DeleteAt(index);
    // Assume OK..
  end;

// Examine the JSON to see if it worked as expected..
json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());
end;