mobileFX WebKitX CEF3 ActiveX 4.x
WebKitXCEF3Lib ActiveX Control / WebKitXCEF3 Object / OnBrowserReady Event
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    OnBrowserReady Event
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    Description

    Fired when the Chromium Embedded Browser has been created and it is ready to start loading URLs and HTML. Handle this event to enable JavaScript and Open your URL (or load plain HTML)

    Syntax
    Visual Basic
    Public Event OnBrowserReady()
    Remarks

    OnBrowserReady event notifies you that CEF3 processes and WebKitX control have been successfully created and the Interprocess Communication Mechanism (IPC) is established. At this point you can define secondary behavioral parameters such as focus control, formatting APIs, script downloading control, etc. but most importantly after OnBrowserReady event you can successfully start loading URLs for browsing or editing.

    Loading Sequence

    Loading Sequence

    WebKitX provides several Events during its initialization, creation of the browser and loading of a URL. First you need to set the licensing information by handling the early Form Loading or Creation event. Then you can control CEF Browser creation by handling the OnCreate event. Once the browser is ready it will emit the the OnBrowserReady event where you can enable JavaScript or HTML5 editing parameters. In OnBrowserReady you should also load the HTML5 markup or navigate to the URL you want to load.

    During loading WebKitX will fire several loading events such as OnLoadStart and OnLoadEnd. If you are loading HTML with frames (IFRAMEs) then some events will fire multiple times, such as OnPageLoadStart and OnPageLoadEnd. When the main frame is loaded WebKitX will fire OnLoadEnd and when all frames have loaded WebKitX will fire the OnPageComplete event.

    When you receive the OnLoadEnd and OnPageLoadEnd events, it means that network-wise the contents have downloaded but HTML-wise the contents might not be fully parsed yet. In HTML terms this means that document.readyState value might not not set to complete. Pages in window or sub frames might be in interactive state and resources might be loading in the background. The only event that guarantees that the main window frame and all sub-frames have document.readyState = complete is OnPageComplete.

    Internally, WebKitX uses an asynchronous task that checks the document.readyState for all frames; if this check result is "complete" with a count equal to browser frames, then the event is fired. If some frames have loaded while other frames have failed, the event will not fire. The check takes place on a fresh HTML DOM snapshot obtained every time at the moment of the check, and examines the current number of frames. The frames must remain unchanged for 3 seconds before the event is fired; this way, any dynamic loading or unloading of frames is taken into account.

    Please note that some frameworks such as Angular and React dynamically load portions of the page. WebKitX events will keep firing while dynamic content is downloaded. You need to examine the behavior of the control in relation with the web site you want to display and adjust your event handling accordingly. 

    Example
    Private Sub WebKitX1_OnBrowserReady()
        
        On Error Resume Next
        
        ' Restore focus to WebKitX after a command is executed (form a menu or context menu)
        WebKitX1.ExecCommandSetFocus = True
        
        ' Enable mobileFX formatting vs. CEF3 formatting (Recommended)
        WebKitX1.FormatUsingInternalSelectionAPI = True
        
        ' Allow JavaScript download (sometimes scripts such as parallax mess with HTML5 styles)
        WebKitX1.DownloadScripts = False
        mnuDownloadScripts.Checked = False
        
        ' Initial HTML to show (optional)
        
        If LoadFile <> "" Then
            WebKitX1.Open LoadFile
            LoadFile = ""
        Else
            WebKitX1.HTML = "<html><body></body></html>"
        End If
        
        'WebKitX1.Open "file:///my_path/index.html"
        
    End Sub
    private void WebKitXCEF31_OnBrowserReady(object sender, EventArgs e)
    {
        WebKitXCEF31.ExecCommandSetFocus = true;
        WebKitXCEF31.FormatUsingInternalSelectionAPI = true;
        WebKitXCEF31.DownloadScripts = false;
        menuItemDownloadScript.Checked = false;
        if (LoadFile != "")
        {
            WebKitXCEF31.Open(LoadFile);
            LoadFile = "";
        }
        else
        {
            WebKitXCEF31.HTML = "<html><body></body></html>";
        }
    }
    See Also