エラーの後にJavaScriptを実行し続けるにはどうすればよいですか？

Question

Delphi 2010 WebBrowserでjavascriptエラー処理に問題があります。

有効なサイレントプロパティでWebBrowserを使用しています。 OKと思われますが、バグのあるサイトには1つの問題があります。エラーが発生してもスクリプトの一部のように見えます。いくつかのスクリプトの結果はIEと少し異なります。

この問題をどのように解決できますか？

Answer 1

IOleCommandTargetを使用し、そのIOleCommandTarget.Execメソッドでは、OLECMDID_SHOWSCRIPTERRORコマンドをキャッチすることができます。

次の例では介在クラスを使用していますので、このコードをユニットに配置すると、フォーム上のWebブラウザまたはこのユニットで動的に作成されたブラウザのみがこの動作を行います。

uses 
    SHDocVw, ActiveX; 

type 
    TWebBrowser = class(SHDocVw.TWebBrowser, IOleCommandTarget) 
    private 
    function QueryStatus(CmdGroup: PGUID; cCmds: Cardinal; prgCmds: POleCmd; 
     CmdText: POleCmdText): HRESULT; stdcall; 
    function Exec(CmdGroup: PGUID; nCmdID, nCmdexecopt: DWORD; 
     const vaIn: OleVariant; var vaOut: OleVariant): HRESULT; stdcall; 
    end; 

implementation 

function TWebBrowser.QueryStatus(CmdGroup: PGUID; cCmds: Cardinal; 
    prgCmds: POleCmd; CmdText: POleCmdText): HRESULT; stdcall; 
begin 
    Result := S_OK; 
end; 

function TWebBrowser.Exec(CmdGroup: PGUID; nCmdID, nCmdexecopt: DWORD; 
    const vaIn: OleVariant; var vaOut: OleVariant): HRESULT; stdcall; 
begin 
    // presume that all commands can be executed; for list of available commands 
    // see SHDocVw.pas unit, using this event you can suppress or create custom 
    // events for more than just script error dialogs, there are commands like 
    // undo, redo, refresh, open, save, print etc. etc. 
    // be careful, because not all command results are meaningful, like the one 
    // with script error message boxes, I would expect that if you return S_OK, 
    // the error dialog will be displayed, but it's vice-versa 
    Result := S_OK; 

    // there's a script error in the currently executed script, so 
    if nCmdID = OLECMDID_SHOWSCRIPTERROR then 
    begin 
    // if you return S_FALSE, the script error dialog is shown 
    Result := S_FALSE; 
    // if you return S_OK, the script error dialog is suppressed 
    Result := S_OK; 
    end; 
end; 

Answer 2

これは私の推奨する実装です。

uses 
    SHDocVw, ActiveX; 

type 
    TWebBrowser = class(SHDocVw.TWebBrowser, IOleCommandTarget) 
    private 
    function QueryStatus(CmdGroup: PGUID; cCmds: Cardinal; prgCmds: POleCmd; 
     CmdText: POleCmdText): HRESULT; stdcall; 
    function Exec(CmdGroup: PGUID; nCmdID, nCmdexecopt: DWORD; 
     const vaIn: OleVariant; var vaOut: OleVariant): HRESULT; stdcall; 
    end; 

implementation 

function TWebBrowser.QueryStatus(CmdGroup: PGUID; cCmds: Cardinal; 
    prgCmds: POleCmd; CmdText: POleCmdText): HRESULT; stdcall; 
begin 
    // MSDN notes that a command target must implement this function; E_NOTIMPL is not a 
    // valid return value. Be careful to return S_OK, because we notice that context menu 
    // of Web page "Add to Favorites..." becomes disabled. Another MSDN document shows an 
    // example with default return value OLECMDERR_E_NOTSUPPORTED. 
    // http://msdn.microsoft.com/en-us/library/bb165923(v=vs.80).aspx 
    Result := OLECMDERR_E_NOTSUPPORTED; 
end; 

function TWebBrowser.Exec(CmdGroup: PGUID; nCmdID, nCmdexecopt: DWORD; 
    const vaIn: OleVariant; var vaOut: OleVariant): HRESULT; stdcall; 
var 
    ShowDialog, InterpretScript: Boolean; 
begin 
    if CmdGroup = nil then 
    begin 
    Result := OLECMDERR_E_UNKNOWNGROUP; 
    Exit; 
    end; 

    // MSDN notes that a command target must implement this function; E_NOTIMPL is not a 
    // valid return value. Be careful to return S_OK, because we notice some unhandled 
    // commands behave unexpected with S_OK. We assumed that a return value 
    // OLECMDERR_E_NOTSUPPORTED means to use the default behavior. 
    Result := OLECMDERR_E_NOTSUPPORTED; 

    if IsEqualGUID(CmdGroup^, CGID_DocHostCommandHandler) then 
    begin 
    // there's a script error in the currently executed script, so 
    if nCmdID = OLECMDID_SHOWSCRIPTERROR then 
    begin 
     ShowDialog := True; 
     InterpretScript := False; 

     // Implements an event if you want, so that your application is able to choose the way of handling script errors at runtime. 
     if Assigned(OnNotifyScriptError) then 
     OnNotifyScriptError(Self, ShowDialog, InterpretScript); 

     if ShowDialog then 
     Result := S_FALSE 
     else 
     Result := S_OK; 
     vaOut := InterpretScript; // Without setting the variable to true, further script execution will be cancelled. 
    end; 
    end; 
end;