(Unicode C) Call a JavaScript Function Returning a String

See more JavaScript Examples

Note: This example requires Chilkat v11.4.0 or greater.

Chilkat C/C++ Library Downloads
MS Visual C/C++ C++ Builder Linux C/C++ Alpine Linux C/C++	MacOS C/C++ iOS C/C++ Android C/C++ MinGW C/C++

#include <C_CkStringBuilderW.h>
#include <C_CkJsW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilderW sbScript;
    HCkJsW js;
    HCkJsonObjectW result;
    HCkJsonObjectW funcCall;
    const wchar_t *retval;

    success = FALSE;

    // This is the JavaScript function we'll call:

    // function greet(name) {
    //     return "Hello, " + name + "!";
    // }

    sbScript = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbScript,L"function greet(name) { return \"Hello, \" + name + \"!\"; }");

    js = CkJsW_Create();

    result = CkJsonObjectW_Create();
    CkJsonObjectW_putEmitCompact(result,FALSE);

    // Call Eval to add the function to the context's global object
    success = CkJsW_Eval(js,sbScript,result);
    if (success == FALSE) {
        // Examine the result for an exception.
        wprintf(L"%s\n",CkJsonObjectW_emit(result));

        // Also examine the LastErrorText.
        wprintf(L"%s\n",CkJsW_lastErrorText(js));
        CkStringBuilderW_Dispose(sbScript);
        CkJsW_Dispose(js);
        CkJsonObjectW_Dispose(result);
        return;
    }

    // ------------------------------------------------------------------------------
    // Call the function greet("Michael")

    funcCall = CkJsonObjectW_Create();

    // Create JSON specifying the function name and arguments

    // {
    //   "name": "greet",
    //   "args": [ "Michael" ]
    // }

    CkJsonObjectW_UpdateString(funcCall,L"name",L"greet");
    CkJsonObjectW_UpdateString(funcCall,L"args[0]",L"Michael");

    success = CkJsW_CallFunction(js,funcCall,result);
    if (success == FALSE) {
        // Examine the result for an exception.
        wprintf(L"%s\n",CkJsonObjectW_emit(result));

        // Also examine the LastErrorText.
        wprintf(L"%s\n",CkJsW_lastErrorText(js));
        CkStringBuilderW_Dispose(sbScript);
        CkJsW_Dispose(js);
        CkJsonObjectW_Dispose(result);
        CkJsonObjectW_Dispose(funcCall);
        return;
    }

    wprintf(L"%s\n",CkJsonObjectW_emit(result));

    // Output:
    // {
    //   "type": "string",
    //   "value": "Hello, Michael!"
    // }

    retval = CkJsonObjectW_stringOf(result,L"value");
    wprintf(L"%s\n",retval);

    // Output:
    // Hello, Michael!


    CkStringBuilderW_Dispose(sbScript);
    CkJsW_Dispose(js);
    CkJsonObjectW_Dispose(result);
    CkJsonObjectW_Dispose(funcCall);

    }