How to call mfc C++ function in HTML JavaScript and how to call JavaScript Function in mfc C++? [closed]

Question

I search on internet 1 week regularly no solution. I found one http://www.codeproject.com/Articles/2352/JavaScript-call-from-C. But that solution is very difficult to understand.

This program can call JavaScript but online. I just want to call JavaScript Internally. For example test.htm inside the project. Just 1 simple function of JavaScript and 1 simple function of c++. Please Help.

According to my project any simple function. For example adding from JavaScript or multiplication from c++ etc.

Answer 1

This is the way to call javascript function from MFC application
Suppose this is a javascript function in your html file.
JAVSCRIPT function

There may be different type of javascript function
Type 1: No arguments, No return Value

function myfunction()
{
    Alert('Hey I am Here');
} 

Type 2: having Arguments with No return Value

function myfunction1(value)
{
    Alert(value);
} 

Type 3: Arguments may or may not have with return Value

function myfunction2(value)
{
    return value;
}

---

This function is used to call javascript function

BOOL CMyDlg::CallClientScript(LPCTSTR pStrFuncName, CStringArray* pArrFuncArgs, CComVariant* pOutVarRes)
{
BOOL bRes = FALSE;
CComVariant vaResult;
CComPtr<IHTMLDocument2> pIDoc2;
if(SUCCEEDED(this->GetDHtmlDocument(&pIDoc2)))  //Uses CDHtmlDialog as 'this'
{
    //Getting IDispatch for Java Script objects
    CComPtr<IDispatch> spScript;
    if(SUCCEEDED(pIDoc2->get_Script(&spScript)))
    {
        //Find dispid for given function in the object
        CComBSTR bstrMember(pStrFuncName);
        DISPID dispid = NULL;
        if(SUCCEEDED(spScript->GetIDsOfNames(IID_NULL, &bstrMember, 1, LOCALE_USER_DEFAULT, &dispid)))
        {
            const int arraySize = pArrFuncArgs ? pArrFuncArgs->GetSize() : 0;

            //Putting parameters  
            DISPPARAMS dispparams;
            memset(&dispparams, 0, sizeof dispparams);
            dispparams.cArgs      = arraySize;
            dispparams.rgvarg     = new VARIANT[dispparams.cArgs];
            dispparams.cNamedArgs = 0;

            for( int i = 0; i < arraySize; i++)
            {
                CComBSTR bstr = pArrFuncArgs->GetAt(arraySize - 1 - i); // back reading
                bstr.CopyTo(&dispparams.rgvarg[i].bstrVal);
                dispparams.rgvarg[i].vt = VT_BSTR;
            }

            EXCEPINFO excepInfo;
            memset(&excepInfo, 0, sizeof excepInfo);
            UINT nArgErr = (UINT)-1;  // initialize to invalid arg

            //Call JavaScript function         
            if(SUCCEEDED(spScript->Invoke(dispid, IID_NULL, 0, DISPATCH_METHOD, &dispparams, &vaResult, &excepInfo, &nArgErr)))
            {
                //Done!
                bRes = TRUE;
            }
            //Free mem
            delete [] dispparams.rgvarg;
        }
    }
}

if(pOutVarRes)
    *pOutVarRes = vaResult;

return bRes;
}

How to use?
On click of any button you can call this function, for example

onbuttonclickOk()
{
    CStringArray arrArgs;
    CComVariant varRes;
    //arrArgs.Add(_T("1"));//you can add value to CStringArray 
    //arrArgs.Add(_T("2"));//if your javascript function having any arguments
    CallClientScript(L"myfunction",&arrArgs,&varRes);
}

How to get return value of javaScript function?
If your javascript function is returning any value, it will be stored invarRes variable.
you can get return value like

CString strTmp;
if(CallClientScript(L"myfunction3",&arrArgs,&varRes))
{
    if(varRes.vt == VT_BSTR){
        strTmp = varRes.bstrVal;// return value of javascript function.
    }
}

EDIT:
Work with edit control
suppose you have an edit control like this

<input type="text" id="MyEdit" />  

In DoDataExchange add one line

void CMyDlg::DoDataExchange(CDataExchange* pDX)
{
    CDHtmlDialog::DoDataExchange(pDX);
    DDX_DHtml_ElementInnerText(pDX, _T("MyEdit"), m_strMyEdit);// add this line
}

m_strMyEdit is a CString variable you can declare in your .h file.
OnInitDialog, you can give any value to show in edit control, like:

m_strMyEdit = _T("Enter anything");

And if you want to update editbox value later in your program just add these lines

UpdateData();
m_strMyEdit =_T("Hello World");// give new value
UpdateData(FALSE);

if you want to access editbox value you can directly use m_strMyEdit variable.
I think this will help you..!!!