I've implemented ReCaptcha in MVC3 using ReCaptcha.net NuGet package http://recaptchanet.codeplex.com/wikipage?title=How%20to%20Use%20Recaptcha%20in%20an%20ASP.NET%20MVC%20Web%20Application. All working well, except I'd like to see if I can implement this as Async as it is sometimes quite slow, and we may have some volume on these pages.
The instructions say
RecaptchaVerificationResult recaptchaResult = await recaptchaHelper.VerifyRecaptchaResponse();
if (recaptchaResult != RecaptchaVerificationResult.Success)
{
ModelState.AddModelError("", "Incorrect captcha answer.");
}
however, this is using the MVC4 await syntax. Is there a way I can use this method within the MVC3 async framework?
I did try a quick hack, converting the controller to AsyncController naming the method with an Async suffix and wrapping the entire action in a Task.Factory.StartNew(() => { ... }); while using the non-async syntax, but RecaptchaVerificationHelper recaptchaHelper = this.GetRecaptchaVerificationHelper(); complains about a lack of HTTPContext.
So, can anyone help me with doing ReCaptcha asynchronously in MVC3
In the end, I've dropped using the NuGet package, and simply process the captcha's using the code below, binding the recaptcha fields in the controller method.
public bool ProcessCaptcha(string recaptcha_challenge_field, string recaptcha_response_field)
{
const string verifyUrl = "http://www.google.com/recaptcha/api/verify";
var res = true;
var ip = Request.UserHostAddress;
if (ip == "::1") ip = "127.0.0.1";
var myParameters = string.Format("privatekey={0}&remoteip={1}&challenge={2}&response={3}", Config.CaptchPriv, ip, recaptcha_challenge_field, recaptcha_response_field);
using (WebClient wc = new WebClient())
{
wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
string HtmlResult = wc.UploadString(verifyUrl, myParameters);
var split = HtmlResult.Split('\n');
if (split[0] == "false") res = false;
}
return res;
}
With this in place, I split my original controller method into a Async/Completed pair, and wrapped the work it does in Task.Factory.StartNew(() => { ... }), following the pattern outlined here http://www.deanhume.com/Home/BlogPost/mvc-asynchronous-controller---the-basics/67 which seems to work perfectly.
Related
As a sample of what I'm trying to accomplish, here in MapPost I'm manually parsing the body of the HTTP request.
// Program.cs
using System.Text.Json;
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
Type[] types = new[] { typeof(SampleDto1), typeof(SampleDto2), <other unknown types> };
foreach (var type in types)
{
app.MapPost(type.Name, async (HttpContext httpContext) =>
{
var request = await JsonSerializer.DeserializeAsync(
httpContext.Request.Body,
type,
new JsonSerializerOptions(JsonSerializerDefaults.Web),
httpContext.RequestAborted);
return Results.Ok(request);
});
}
app.Run();
internal record SampleDto1(string Input) { }
internal record SampleDto2(string Input) { }
This works, yay! However, ... ASP.NET Core's MVC has all these sophisticated ModelBinding functionality and I really would like to use that. Because that opens up possibilities for binding to querystring parameters and other sources instead of only the request body.
Basically I want to replace the call to JsonSerializer with a call to framework code.
I've been browsing the ASP.NET Core source code and at first the DefaultModelBindingContext looked promising. However, I soon stumbled on some internal classes which I couldn't access from my code.
Long story short, .. is it at all possible to plug-in to MVC's model binding from application code?
Update: Although it doesn't show from the initial question, the solution should work dynamically with any request type. Not only SampleDto1 and SampleDto2. That's why explicit parameter binding from Minimal API won't do the trick.
You could try the codes :
using Microsoft.AspNetCore.Mvc;
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
builder.Services.AddSingleton<Service>();
app.MapPost("/{id}", ([FromRoute] int id,
[FromQuery(Name = "p")] int page,
[FromBody]SampleDto1 sample1,
[FromBody] SampleDto2 sample2,
[FromServices] Service service,
[FromHeader(Name = "Content-Type")] string contentType)
=> { });
app.Run();
internal record SampleDto1(string Input) { }
internal record SampleDto2(string Input) { }
You could read the official document for more details:
https://learn.microsoft.com/en-us/aspnet/core/fundamentals/minimal-apis?view=aspnetcore-6.0#explicit-parameter-binding
I am struggling with uploading an image from thew client-side to a folder on the server-side in .Net Core.I used Postman to check if the method on the server-side is working and it does without any problem,but when I try to upload an image from the client-side,I get an error on the server-side of type NullReferenceException:Object reference not set to an instance of an object.This is the Post method on the server-side:
[HttpPost]
public async Task Post(IFormFile file)
{
if (string.IsNullOrWhiteSpace(_environment.WebRootPath))
{
_environment.WebRootPath = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot");
}
var uploads = Path.Combine(_environment.WebRootPath, "uploads");
//var fileName = file.FileName.Split('\\').LastOrDefault().Split('/').LastOrDefault();
if (!Directory.Exists(uploads)) Directory.CreateDirectory(uploads);
if (file.Length > 0)
{
using (var fileStream = new FileStream(Path.Combine(uploads, file.FileName), FileMode.Create))
{
await file.CopyToAsync(fileStream);
}
}
}
Apparently the method is thrown where I check if the length of the file is bigger than 0.On the client-side I get error "500 internal server error" and I tried to check using the debugger where exactly the error is thrown but i can't find anything that could resemble an error of some sort.This is the API method for the client-side:
public async Task UploadPictureAsync(MediaFile image)
{
User user = new User();
string pictureUrl = "http://10.0.2.2:5000/api/UploadPicture";
HttpContent fileStreamContent = new StreamContent(image.GetStream());
// user.Picture=GetImageStreamAsBytes(image.GetStream());
fileStreamContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data") {FileName=Guid.NewGuid() + ".Png",Name="image"};
fileStreamContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
HttpClientHandler clientHandler = new HttpClientHandler();
clientHandler.ServerCertificateCustomValidationCallback = (sender, cert, chain, sslPolicyErrors) => { return true; };
using (var client = new HttpClient(clientHandler))
{
using (var formData = new MultipartFormDataContent())
{
formData.Add(fileStreamContent);
var response = await client.PostAsync(pictureUrl, formData);
if(response.IsSuccessStatusCode)
{
var result = response.Content.ReadAsStringAsync().Result;
}
}
}
}
The image is declared in the Model as byte array:
public byte[] Picture { get; set; }
Does someone understand why my POST method has this behavior since the server-side works perfectly but fails when I try to upload an image from the client-side?What I find weird though is that when i read the error and I look at the Content-Type it is "text/plain" instead of "form-data" and I have tried to set it at the MutipartFormDataContent like this:
formData.Headers.ContentType.MediaType = "multipart/form-data";
I also tried to set the MediaTypeHeaderValue on the client like this:
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/octet-stream"));
I still get the wrong content type.
I have also tried a different approach with Stream instead of MediaFile but without any luck as it did not even hit the break point in debugger mode for the response.Any help would be appreciated! :)
I have managed to find the answer finalllyyyyy!!!The problem was on the client-side as I suspected and guess what,it was all about the correct name.It turns out that since on the server side I have IFormFile file I had to change the client side to take the parameter name "file" instead of image as well so that it could work.Thank you #Jason for the suggestions as I didn't understand the error from the first place and did some debugging on the server-side to help me figure it out.
I have an endpoint that needs to accept a file upload and also some other information from the client request. With the following code I can upload the file successfully but can't seem to figure out how to read the other info.
I make a test request from Postman with the following form data:
image -- myimage.jpg -- of type File
email -- a#b.com -- of type Text
The backend code looks like this:
[HttpPost]
public async Task<HttpResponseMessage> SharePhoto()
{
try
{
var provider = new MultipartMemoryStreamProvider();
var data = await Request.Content.ReadAsMultipartAsync(provider);
// this is how I get the image which I am succesfully passing to EmailService
var item = (StreamContent)provider.Contents[0];
using (var stream = new MemoryStream())
{
await item.CopyToAsync(stream);
String emailAddress;
EmailService.SendSharedPhoto(emailAddress, stream);
return Request.CreateResponse();
}
}
catch
{
// do stuff
}
}
In this example I am able to access provider.Contents[1] but can't seem to be able to get the value from it into emailAddress. I'm thinking it may be possible to use the same trick as the await item.CopyToASync(stream) from the image upload, but I'm hoping I can get a simpler solution to that. Any ideas?
I just barely answered a very similar question to this yesterday. See my answer here complete with sample controller code.
The method I ended up using is:
If the form elements are strings (and it worked for me since the mobiel frontend took responsability for input data) you can do this:
var streamContent = (StreamContent)provider.Contents[1];
var memStream = new MemoryStream();
await streamContent.CopyToAsync(memStream);
var actualString = Encoding.UTF8.GetString(x.ToArray());
If however the field needs to represent a collection of items, like for example the email list: ["a#b.com", "x#c.com"], etc a JavaScriptSerializer can be user, like so:
var streamContent = (StreamContent)provider.Contents[1];
var emailAddresses = await str.ReadAsStringAsync();
var jsSerializer = new JavaScriptSerializer();
var deserializedData = jsSerializer.Deserialize<string[]>(emailAddresses);
Note that this is nowhere near safe, though it is few lines of code and happens to work.
I have had this for a couple of days now.
I have a simple search form. When form is submitted the server searches for some data from another server and return data to the screen. When the submit completes it gets some javascript from the server based on the results returned from the search. the javascript then makes multiple concurrent jquery get requests, lets say 4, to the asp.net mvc3 webapp.
I have demonstrated that all the get requests fire at the same time in Firebug but when debugging my app with VS the breakpoints only get hit once the previous request completes.
The actions are the same but the querys are different; ie
/Home/Details/040801
/Home/Details/040802
/Home/Details/040803
So these are different URLs and, from what i found out, FF should treat them differently.
So my questions are:
Am I missing something obvious?
Does IIS have some funny blocking on the same route?
Is it a session cache issue? I am locking lock (lockobject){} on writes to the common session variables.
Im not using ViewBag or TempData.
The page load times, even when everything is cached in the Session, are still noticeably synchronous.
Windows Server 2008 R2
Using IIS 7.5
ASP.NET MVC 3
VS2010 Chrome or FF browser
I have my routes set up as follows:
routes.MapRoute(
"Default", // Route name
"{controller}/{action}", // URL with parameters
new { controller = "Home", action = "Index" } // Parameter defaults
);
routes.MapRoute("Details", "{controller}/{action}/{id}/{booking}", new { id = UrlParameter.Optional, booking = UrlParameter.Optional});
Nothing special there as you can see.
Sample code from one of the blocked routes:
public ActionResult Details(string id, bool booking = false)
{
if (booking)
{
return BookingDetails(id, true);
}
Dictionary<string, FlightDetails> detailDic;
string scenarioInput;
lock (DetailsLock)
{
if (Session["DetailDic"] == null)
{
Session["DetailDic"] = new Dictionary<string, FlightDetails>();
}
detailDic = (Dictionary<string, FlightDetails>)Session["DetailDic"];
}
if (detailDic.ContainsKey(id))
{
return PartialView("Details", detailDic[id]);
}
lock (GuidLock)
{
if (Session["DetailGuids"] == null)
{
Session["DetailGuids"] = new Dictionary<string, string>();
}
scenarioInput = ((Dictionary<string, string>)Session["DetailGuids"])[id];
}
// query results list
string queryText = string.Format("<View><Query><Where><Eq><FieldRef Name=\"Title\" /><Value Type=\"Text\">OUT {0}</Value></Eq></Where></Query></View>", scenarioInput);
ListItemCollection oList;
int counter = 0;
do
{
oList = SharepointHelper.GetListFromSharepoint("ListName", queryText, ClientContext);
counter++;
Thread.Sleep(1000);
} while (oList.Count == 0 && counter <= Timeout);
if (oList.Count == 0)
{
return PartialView("Details", (object)null);
}
var item = oList[0];
FlightDetails flightDetails = CreateFlightDetails(id, scenarioInput, item);
lock (DetailsLock)
{
detailDic.Add(id, flightDetails);
}
return PartialView("Details", flightDetails);
}
when using session object in server-side your async calls wait for session object released by other request. Becuase of this async ajax calls act like sync. You have to use session as readonly in that action.
Add this attribute to action you call if you dont write anything to session.
[SessionState(SessionStateBehavior.ReadOnly)]
I am trying to get my flash application to send a request back to the webserver so that it can get some information. So far after reading on stackoverflow for a while and on the net I have some code written, but its not quite working right. I need just a little help tying it all together.
Here is the controller for my webserver
//
// POST: /Home/HoneyPot
[HttpPost]
public ActionResult HoneyPot(bool GetData)
{
//ViewBag.
return View();
}
Here is the ActionScript code that is supposed to be making the request.
// get dynamic page element information
var myData:URLRequest = new URLRequest("http://localhost:59418/HoneyPot");
myData.method = URLRequestMethod.POST;
var vars:URLVariables = new URLVariables();
vars.Input = "GetData=true";
myData.data = vars;
var loader:URLLoader = new URLLoader();
loader.dataFormat = URLLoaderDataFormat.VARIABLES;
loader.addEventListener(Event.COMPLETE, gotPostData_Spiral);
loader.load(myData);
function gotPostData_Spiral(anEvent:Event):void
{
var postData = anEvent.target.data.myVar;
}
Right now when I run the flash code I get this output back:
Error opening URL 'http://localhost:59418/HoneyPot'
Error: Error #2101: The String passed to URLVariables.decode() must be a URL-encoded query
string containing name/value pairs.
at Error$/throwError()
at flash.net::URLVariables/decode()
at flash.net::URLVariables()
at flash.net::URLLoader/onComplete()
Thank you for the help
Instead of:
vars.Input = "GetData=true";
try:
vars.GetData = "true";