Sample code for 30+ languages & platforms
Unicode C++

JavaScript console using Callbacks

See more JavaScript Examples

Demonstrates console output using Chilkat JavaScript with callbacks.

Chilkat Unicode C++ Downloads

Unicode C++
#include <CkStringBuilderW.h>
#include <CkJsW.h>
#include <CkJsonObjectW.h>

#include <CkBaseProgressW.h>

class jsProgress : public CkBaseProgressW {

  public:
  jsProgress() { }
  virtual ~jsProgress() { }

  void ProgressInfo(const wchar_t *name, const wchar_t *value) {
    wprintf(L"%s: %s\n",name,value);
  }

};

void ChilkatSample(void)
    {
    bool success = false;

    // This example demonstrates using the built-in console object.
    // The Javascript run in this example is shown below.

    // Load the JavaScript from a file.
    CkStringBuilderW sbScript;
    success = sbScript.LoadFile(L"qa_data/js_tests/test_console.js",L"utf-8");
    if (success == false) {
        wprintf(L"%s\n",sbScript.lastErrorText());
        return;
    }

    CkJsW js;
    jsProgress js_progress;
    js.put_EventCallbackObject(&js_progress);
    CkJsonObjectW result;

    // Run the JavaScript
    // Results (not console output) go to result.
    // Note: Eval returns the completion value of the script. This is generally the value of the last evaluated expression.
    // In this case, the last evaluated expression is console.log which does not calculate a value. Therefore, it returns undefined.
    success = js.Eval(sbScript,result);
    if (success == false) {
        wprintf(L"%s\n",sbScript.lastErrorText());
        return;
    }

    // We can look at the result, which is "undefined", which is normal and expected.
    wprintf(L"%s\n",result.emit());
    // The result JSON is: {"type":"undefined","value":"undefined"}

    // The console output is received using ProgressInfo callbacks.
    // The output is:

    // log: Hello World, 248, 12.05
    // 
    // error: foo:bar baz
    // 
    // warn: 1 2 3
    // 
    // log: %% %s
    // 
    // log: myApp: {
    //   "appName": "Example",
    //   "version": 1,
    //   "isDebug": true,
    //   "supportedTypes": [
    //     "string",
    //     "number",
    //     "object"
    //   ],
    //   "settings": {
    //     "maxWidgets": 1024,
    //     "allowIO": true
    //   }
    // }
    // 
    // log: App: myApp (Version 1)
    // 
    // {"type":"undefined","value":"undefined"}
    }