Im trying to execute javascript call from C# to the Document loaded in GeckoFX controller, im doing this:
public void evaluateScript(string command)
{
System.Diagnostics.Debug.WriteLine("evaluateScript: " + command);
using (Gecko.AutoJSContext context =
new AutoJSContext(geckoWebBrowser1.Window.JSContext))
{
string result;
context.EvaluateScript(
command,
(nsISupports)geckoWebBrowser1.Window.DomWindow,
out result);
}
}
But this doesn't work, I only found as a solution to call geckoWebBrowser1.Navigate('javascript:functionName(1,2);'); but with this, I can't recover return data from functionName and using the Navigate to make a JavaScript call I think is an error. Is there no way to call JavaScript functions in the DOM and receive their data in C#?
I found the solution, in the version 33, the API has changed a little, its more simple, because by default the EvaluateScript get the WebBrowser DOM as default context if you pass the param, and return the result direct.
public void evaluateScript(string command)
{
System.Diagnostics.Debug.WriteLine("evaluateScript: " + command);
using (Gecko.AutoJSContext context = new AutoJSContext(geckoWebBrowser1.Window.JSContext))
{
var result = context.EvaluateScript(command, geckoWebBrowser1.Window.DomWindow);
}
}
In the older versions, need to specify the context of the EvaluateScript, i found examples in this URL: https://nhabuiduc.wordpress.com/2014/09/18/geckofx-net-webbrowser-setup-and-features/
Related
I am working on a cefsharp based browser and i am trying to implement a search engine into the browser, but the code I have tried docent work, it doesn't really have any errors but when i star the project and type something i the text field nothing happens and it dosent load the search engine i entered into the code, the only time the textbox loads anything is when a url is typed.
This is the code used in the browser that docent work
private void LoadUrl(string url)
{
if (Uri.IsWellFormedUriString(url, UriKind.RelativeOrAbsolute))
{
WebUI.Load(url);
}
else
{
var searchUrl = "https://www.google.com/search?q=" + WebUtility.HtmlEncode(url);
WebUI.Load(searchUrl);
}
}
i have also tried
void LoadURl(String url)
{
if (url.StartsWith("http"))
{
WebUI.Load(url);
}
else
{
WebUI.Load(url);
}
}
i was also suggested to try
private void LoadUrl(string url)
{
if (Uri.IsWellFormedUriString(url, UriKind.RelativeOrAbsolute))
{
WebUI.LoadUrl(url);
}
else
{
var searchUrl = "https://www.google.com/search?q=" + Uri.EscapeDataString(url);
WebUI.LoadUrl(searchUrl);
}
}
We have here really few Information on how your code works. But what I notice is that you use WebUtility.HtmlEncode for the search query. WebUtility has also a WebUtility.UrlEncode Method, that how I understand your question makes more sense it the context. This is the documentation for the method: https://learn.microsoft.com/de-de/dotnet/api/system.net.webutility.urlencode
The Url you are generating is invalid. You need to use Uri.EscapeDataString to convert the url param into a string that can be appended to a url.
// For this example we check if a well formed absolute Uri was provided
// and load that Url, all others will be loaded using the search engine
// e.g. https://github.com will load directly, attempting to load
// github.com will load the search engine with github.com as the query.
//
if (Uri.IsWellFormedUriString(url, UriKind.Absolute))
{
chromiumWebBrowser.LoadUrl(url);
}
else
{
var searchUrl = "https://www.google.com/search?q=" + Uri.EscapeDataString(url);
chromiumWebBrowser.LoadUrl(searchUrl);
}
nothing happens and it dosent load the search engine
You need to subscribe to the LoadError event to get actual error messages. It's up to you to display errors to the user. The following is a basic example:
chromiumWebBrowser.LoadError += OnChromiumWebBrowserLoadError;
private void OnChromiumWebBrowserLoadError(object sender, LoadErrorEventArgs e)
{
//Actions that trigger a download will raise an aborted error.
//Aborted is generally safe to ignore
if (e.ErrorCode == CefErrorCode.Aborted)
{
return;
}
var errorHtml = string.Format("<html><body><h2>Failed to load URL {0} with error {1} ({2}).</h2></body></html>",
e.FailedUrl, e.ErrorText, e.ErrorCode);
_ = e.Browser.SetMainFrameDocumentContentAsync(errorHtml);
}
For testing purposes you can also copy and paste the searchUrl string you've generated and try loading it in Chrome to see what happens, you should also get an error.
Can any one suggest another way to integrate NodeJs in .Net MVC application? I am now using the following code:
public class Startup
{
public async Task<object> Invoke(dynamic input)
{
DepartmentRep person = new DepartmentRep(new MvcAppUsingEdgeJSMongoDbContext());
var department= person.GetAllDepartments();
//var department = "hello";
return department;
}
}
public class DepartmentController : Controller
{
DepartmentRepository departmentRepository = new DepartmentRepository(new MvcAppUsingEdgeJSMongoDbContext());
string connectionString = ConfigurationManager.AppSettings["connectionString"].ToString();
public ViewResult Index()
{
// var clrMethod = Edge.Func("DepartmentRep.cs");
var getData = Edge.Func("./DepartmentRep.dll");
// return View(clrMethod);
return View(departmentRepository.GetAllDepartments());
}
}
It seems to me, you may have a misunderstanding of the EdgeJs use case.
Your Startup/Invoke class/Signature is meant to be called from Node(JavaScript),
And from the code you are showing it looks like you are loading .Net from .Net
Also , as the Invoke signature suggest, It should be asynchronous.
If you want to use node from .Net side. You should check the project documentation from
scripting-nodejs-from-clr downwards.
var func = Edge.Func(#"
return function (data, callback) {
callback(null, 'Node.js welcomes ' + data);
}
");
As you can see there the wrapped code is Javascript, this time running in .Net more specifically running in Node.
The perfect use case IMMO is the Socket-Server, that is, something Node does better than .Net (IMMO again)
Which is in perfect contrast with the .Net Ado Sql Server access from NodeJs, a .Net Specialization from NodeJs context
I'm quite new in programming multi-threading and I could not understand from the xelium example how I could execute a javascript and get the return value.
I have tested:
browser.GetMainFrame().ExecuteJavaScript("SetContent('my Text.')", null, 0);
the javascript is executed, but I this function don’t allow me to get the return value.
I should execute the following function to get all the text the user have written in the box..
browser.GetMainFrame().ExecuteJavaScript("getContent('')", null, 0);
the function TryEval should do this…
browser.GetMainFrame().V8Context.TryEval("GetDirtyFlag", out returninformation , out exx);
But this function can’t be called from the browser, I think it must be called from the renderer? How can I do so?
I couldn’t understand the explanations about CefRenderProcessHandler and OnProcessMessageReceived.. How to register a Scriptable Object and set my javascript & parameters?
Thx for any suggestions how I could solve this!
I have been struggling with this as well. I do not think there is a way to do this synchronously...or easily :)
Perhaps what can be done is this:
From browser do sendProcessMessage with all JS information to renderer
process. You can pass all kinds of parameters to this call in a structured way so encapsulating the JS method name and params in order should not be difficult to do.
In renderer process (RenderProcessHandler onProcessMessageReceived method) do TryEval on the V8Context and get the return value via out parameters and sendProcessMessage back to the
browser process with the JS return value (Note that this supports ordinary return semantics from your JS method).You get the browser instance reference in the onProcessMessageReceived so it is as easy as this (mixed pseudo code)
browser.GetMainFrame().CefV8Context.tryEval(js-code,out retValue, out exception);
process retValue;
browser.sendProcessMessage(...);
Browser will get a callback in the WebClient in onProcessMessageReceived.
There is nothing special here in terms of setting up JS. I have for example a loaded html page with a js function in it. It takes a param as input and returns a string. in js-code parameter to TryEval I simply provide this value:
"myJSFunctionName('here I am - input param')"
It is slightly convoluted but seems like a neat workable approach - better than doing ExecuteJavaScript and posting results via XHR on custom handler in my view.
I tried this and it does work quite well indeed....and is not bad as it is all non-blocking. The wiring in the browser process needs to be done to process the response properly.
This can be extended and built into a set of classes to abstract this out for all kinds of calls..
Take a look at the Xilium demo app. Most of the necessary wiring is already there for onProcessMessage - do a global search. Look for
DemoRendererProcessHandler.cs - renderer side this is where you will invoke tryEval
DemoApp.cs - this is browser side, look for sendProcessMessage - this will initiate your JS invocation process.
WebClient.cs - this is browser side. Here you receive messages from renderer with return value from your JS
Cheers.
I resolved this problem by returning the result value from my JavaScript function back to Xilium host application via an ajax call to a custom scheme handler. According to Xilium's author fddima it is the easiest way to do IPC.
You can find an example of how to implement a scheme handler in the Xilium's demo app.
Check out this post: https://groups.google.com/forum/#!topic/cefglue/CziVAo8Ojg4
using System;
using System.Windows.Forms;
using Xilium.CefGlue;
using Xilium.CefGlue.WindowsForms;
namespace CefGlue3
{
public partial class Form1 : Form
{
private CefWebBrowser browser;
public Form1()
{
InitializeCef();
InitializeComponent();
}
private static void InitializeCef()
{
CefRuntime.Load();
CefMainArgs cefArgs = new CefMainArgs(new[] {"--force-renderer-accessibility"});
CefApplication cefApp = new CefApplication();
CefRuntime.ExecuteProcess(cefArgs, cefApp);
CefSettings cefSettings = new CefSettings
{
SingleProcess = false,
MultiThreadedMessageLoop = true,
LogSeverity = CefLogSeverity.ErrorReport,
LogFile = "CefGlue.log",
};
CefRuntime.Initialize(cefArgs, cefSettings, cefApp);
}
private void Form1_Load(object sender, EventArgs e)
{
browser = new CefWebBrowser
{
Visible = true,
//StartUrl = "http://www.google.com",
Dock = DockStyle.Fill,
Parent = this
};
Controls.Add(browser);
browser.BrowserCreated += BrowserOnBrowserCreated;
}
private void BrowserOnBrowserCreated(object sender, EventArgs eventArgs)
{
browser.Browser.GetMainFrame().LoadUrl("http://www.google.com");
}
}
}
using Xilium.CefGlue;
namespace CefGlue3
{
internal sealed class CefApplication : CefApp
{
protected override CefRenderProcessHandler GetRenderProcessHandler()
{
return new RenderProcessHandler();
}
}
internal sealed class RenderProcessHandler : CefRenderProcessHandler
{
protected override void OnWebKitInitialized()
{
CefRuntime.RegisterExtension("testExtension", "var test;if (!test)test = {};(function() {test.myval = 'My Value!';})();", null);
base.OnWebKitInitialized();
}
}
}
In my WinForms application I need to call javascript function from my WebBrowser control. I used Document.InvokeScript and it works perfect with functions alone e.g
Document.InvokeScript("function").
But when i want to call javascript object method e.g.
Document.InvokeScript("obj.method")
it doesn't work. Is there a way to make it work? Or different solution to this problem? Without changing anything in the javascript code!
Thanks in advance :)
The example in the documentation does NOT include the parenthesis.
private void InvokeScript()
{
if (webBrowser1.Document != null)
{
HtmlDocument doc = webBrowser1.Document;
String str = doc.InvokeScript("test").ToString() ;
Object jscriptObj = doc.InvokeScript("testJScriptObject");
Object domOb = doc.InvokeScript("testElement");
}
}
Try
Document.InvokeMethod("obj.method");
Note that you can pass arguments if you use HtmlDocument.InvokeScript Method (String, Object[]).
Edit
Looks like you aren't the only one with this issue: HtmlDocument.InvokeScript - Calling a method of an object . You can make a "Proxy function" like the poster of that link suggests. Basically you have a function that invokes your object's function. It's not an ideal solution, but it'll definitely work. I'll continue looking to see if this is possible.
Another post on same issue: Using WebBrowser.Document.InvokeScript() to mess around with foreign JavaScript . Interesting solution proposed by C. Groß on CodeProject:
private string sendJS(string JScript) {
object[] args = {JScript};
return webBrowser1.Document.InvokeScript("eval",args).ToString();
}
You could make that an extension method on HtmlDocument and call that to run your function, only using this new function you WOULD include parenthesis, arguments, the whole nine yards in the string you pass in (since it is just passed along to an eval).
Looks like HtmlDocument does not have support for calling methods on existing objects. Only global functions. :(
Unfortunately you can't call object methods out of the box using WebBrowser.Document.InvokeScript.
The solution is to provide a global function on the JavaScript side which can redirect your call. In the most simplistic form this would look like:
function invoke(method, args) {
// The root context is assumed to be the window object. The last part of the method parameter is the actual function name.
var context = window;
var namespace = method.split('.');
var func = namespace.pop();
// Resolve the context
for (var i = 0; i < namespace.length; i++) {
context = context[namespace[i]];
}
// Invoke the target function.
result = context[func].apply(context, args);
}
In your .NET code you would use this as follows:
var parameters = new object[] { "obj.method", yourArgument };
var resultJson = WebBrowser.Document.InvokeScript("invoke", parameters);
As you mention that you cannot change anything to your existing JavaScript code, you'll have to inject the above JavaScript method in some how. Fortunately the WebBrowser control can also do for you by calling the eval() method:
WebBrowser.Document.InvokeScript("eval", javaScriptString);
For a more robust and complete implementation see the WebBrowser tools I wrote and the article explaining the ScriptingBridge which specifically aims to solve the problem you describe.
webBrowser.Document.InvokeScript("execScript", new object[] { "this.alert(123)", "JavaScript" })
for you supposed to be like this
webBrowser.Document.InvokeScript("execScript", new object[] { "obj.method()", "JavaScript" })
I am using a jQuery Ajax control from this site http://abeautifulsite.net/2008/03/jquery-file-tree/
I have it all working. I tried to ask a support question but never heard back, thinking maybe someone on here can shed some light on the situation.
Basically what I am trying to do, is on a file selection run an action that returns a JsonResult, that gives more details about the file and then show them to the screen in a container. While I debug, the method gets hit, returns the correct data. After the return in the ajax call i get a error in firebug say the recursionlimit exceeded. I am not sure how to get around this...I thought I could use the callback of the fileTree(options, callback) method provided but that is not fired on selection of the file only the initialization of the file tree. Any ideas?
Heres what I did via JavaScript
function initFileTree() {
$('#fileTree').fileTree({ root: '/', script: '/Scripts/filetree/jqueryFileTree.aspx', multiFolder: false, expandEasing: 'easeOutBounce', collapseEasing: 'easeOutBounce' }, function(file) {
getFileDetails(file);
});
}
function getFileDetails(file) {
// alert(file);
$.getJSON('/Files.mvc/GetFileDetails', { Data: file }, function(data) {
$('#fileDetail').html('<h6>Selected File: ' + data.Length + '</h6>');
}, 'json');
}
Here is my action that take the data and returns a JsonResult
public virtual JsonResult GetFileDetails(string data)
{
string pageMessage = null;
FileInfo fileInfo = null;
try
{
fileInfo = new FileInfo(data);
}
catch (Exception e)
{
pageMessage = e.Message;
}
return Json(fileInfo);
}
Apparently returning a FileInfo obj is not acceptable for a JsonResult. Simplifying the return, I changed it to:
return Json("helloWorld");
and all my problems went away. Not sure why it cares that I was attempting to return a FileInfo type but either way problem solved when I changed it to return a string. So now I just create a small wrapper class to hold the data I want to pass back and life is good.
Thanks! Hope this helps someone else.