Delphi DLL

Call a JavaScript Function Returning an Array

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns an array. Delphi DLL

var
success: Boolean;
sbScript: HCkStringBuilder;
js: HCkJs;
result: HCkJsonObject;
funcCall: HCkJsonObject;
count: Integer;
i: Integer;

begin
success := False;

//  ----------------------------------------------------------------------------------
//  The Javascript functions called in this example are shown at the bottom of this page.
//  -----------------------------------------------------------------------------------

sbScript := CkStringBuilder_Create();
success := CkStringBuilder_LoadFile(sbScript,'js_function_returning_array.js','utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add(CkStringBuilder__lastErrorText(sbScript));
    Exit;
  end;

js := CkJs_Create();

result := CkJsonObject_Create();
CkJsonObject_putEmitCompact(result,False);

//  Call Eval to add the function to the context's global object
success := CkJs_Eval(js,sbScript,result);
if (success = False) then
  begin
    //  Examine the result for an exception.
    Memo1.Lines.Add(CkJsonObject__emit(result));

    //  Also examine the LastErrorText.
    Memo1.Lines.Add(CkJs__lastErrorText(js));
    Exit;
  end;

//  ------------------------------------------------------------------------------
//  Call each function

funcCall := CkJsonObject_Create();

//  Create JSON specifying the function name and arguments
//  The function has no arguments, so we only specify the name.

CkJsonObject_UpdateString(funcCall,'name','getDays');

success := CkJs_CallFunction(js,funcCall,result);
if (success = False) then
  begin
    //  Examine the result for an exception.
    Memo1.Lines.Add(CkJsonObject__emit(result));

    //  Also examine the LastErrorText.
    Memo1.Lines.Add(CkJs__lastErrorText(js));
    Exit;
  end;

Memo1.Lines.Add(CkJsonObject__emit(result));

//  Output:
//  {
//    "type": "array",
//    "value": [
//      "Monday",
//      "Tuesday",
//      "Wednesday",
//      "Thursday",
//      "Friday"
//    ]
//  }

//  Access each array value..
count := CkJsonObject_SizeOfArray(result,'value');
i := 0;
while i < count do
  begin
    CkJsonObject_putI(result,i);
    Memo1.Lines.Add(CkJsonObject__stringOf(result,'value[i]'));
    i := i + 1;
  end;

//  ------------------------------------------------------------------------------
//  Call the getRange(start,end) function

CkJsonObject_Clear(funcCall);
CkJsonObject_UpdateString(funcCall,'name','getRange');
CkJsonObject_UpdateInt(funcCall,'args[0]',14);
CkJsonObject_UpdateInt(funcCall,'args[1]',21);
success := CkJs_CallFunction(js,funcCall,result);
Memo1.Lines.Add(CkJsonObject__emit(result));

//  Output:
//  {
//    "type": "array",
//    "value": [
//      14,
//      15,
//      16,
//      17,
//      18,
//      19,
//      20,
//      21
//    ]
//  }

count := CkJsonObject_SizeOfArray(result,'value');
i := 0;
while i < count do
  begin
    CkJsonObject_putI(result,i);
    Memo1.Lines.Add(IntToStr(CkJsonObject_IntOf(result,'value[i]')));
    i := i + 1;
  end;

//  ------------------------------------------------------------------------------
//  Call the getEmployees() function

CkJsonObject_Clear(funcCall);
CkJsonObject_UpdateString(funcCall,'name','getEmployees');
success := CkJs_CallFunction(js,funcCall,result);
Memo1.Lines.Add(CkJsonObject__emit(result));

//  Output:
//  {
//    "type": "array",
//    "value": [
//      {
//        "id": 101,
//        "name": "Alice",
//        "role": "Dev"
//      },
//      {
//        "id": 102,
//        "name": "Bob",
//        "role": "Manager"
//      }
//    ]
//  }

count := CkJsonObject_SizeOfArray(result,'value');
i := 0;
while i < count do
  begin
    CkJsonObject_putI(result,i);
    Memo1.Lines.Add('name: ' + CkJsonObject__stringOf(result,'value[i].name'));
    Memo1.Lines.Add('role: ' + CkJsonObject__stringOf(result,'value[i].role'));
    Memo1.Lines.Add('id: ' + IntToStr(CkJsonObject_IntOf(result,'value[i].id')));
    Memo1.Lines.Add('');
    i := i + 1;
  end;

CkStringBuilder_Dispose(sbScript);
CkJs_Dispose(js);
CkJsonObject_Dispose(result);
CkJsonObject_Dispose(funcCall);

JavaScript

function getDays() {
    return ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday"];
}

function getRange(start, end) {
    var arr = [];
    for (var i = start; i <= end; i++) {
        arr.push(i);
    }
    return arr;
}
// Usage: getRange(1, 5) -> [1, 2, 3, 4, 5]

function getEmployees() {
    return [
        { id: 101, name: "Alice", role: "Dev" },
        { id: 102, name: "Bob", role: "Manager" }
    ];
}