I am retrieving XML result from thrid-party API to ASP.net web API. Now I want to send this retrieved XML( converted in JSON) to angular typescript file. How can I achieve it?
My approach 1. send JSON from model class to controller and then from the controller to angular service or component's .ts file.
2.post from model class to component's .ts file.
var objJson = new JavaScriptSerializer().Serialize(responseB);
var response = await client.PostAsync("http://localhost:4200/add", new StringContent(objJson, Encoding.UTF8, "application/json"));
var responseString = await response.Content.ReadAsStringAsync();
You can't send something "from a WebAPI to a TypeScript file".
It sounds like you want to send it from the server to a client app in a web browser? If this is the case, then you need the client app to ask for it, or to push it to the client.
If the client initiated the request that had you fetch this resource, then you could send it in the response to the client.
If the client app has some bi-directional connection to your server like socket.io or SignalR, you can send it over that.
Or, depending on the frequency, probability of this happening, you might have the client poll for it.
But it all depends on the state machine of the entire process you are implementing. Does the client app initiate any of this, or this an event that the client does not initiate, but needs to be informed of? If this is the case, you either need to poll or to set up a connection from the client to the server.
Related
I am using SignalR in a Blazor server-side app. I added the Microsoft.AspNetCore.SignalR.Client Nuget package (v5.0.11) to the project, and used the following code to create the hub connection...
HubConnection hubConnection = new HubConnectionBuilder()
.WithUrl("url")
.Build();
await hubConnection.StartAsync();
I then send out a message with the following code (Debug.WriteLine added to confirm what's going on)...
Debug.WriteLine($"{DateTime.Now.ToLongTimeString()} SignalR msg sent");
await hubConnection.SendAsync("Send", "Hello");
The component that is to handle such messages creates the hub connection and hooks up to the On handler as follows...
HubConnection hubConnection = new HubConnectionBuilder()
.WithUrl("url")
.Build();
hubConnection.On<string>("Receive", msg =>
Debug.WriteLine($"{DateTime.Now.ToLongTimeString()} SignalR msg received - {msg}"));
await hubConnection.StartAsync();
When the message is sent out, it is definitely only being sent once (which I can confirm from the output panel, where I only see the "sent" output once), but it is received twice.
Searching around, it seems that a common reason for this is if jQuery was loaded twice. However, I have checked this, and it's not the case. It's only being loaded the once. Furthermore, one of the other developers on the team tried it, and he got the message received 15 times! Even if we had accidentally included jQuery twice, we certainly didn't include it 15 times. Also, he's using exactly the same code as me (checked out from source control), so we should get the same results if this were the issue.
Anyone any idea why this could be happening? Thanks
This can occur when you initialise a HubConnection within a component and don’t configure IDispose or IAsyncDispose on your component to dispose the HubConnection.
In a Blazor Server-Side application there is already a SignalR host pushing updates to the client.
If you want to push updates from a page you can use a Singleton Service to handle the communication.
If you set up your own SignalR hub and use the SignalR client in your components, your application is something like the diagram below:
As you can see, the client is actually running on the server. The SignalR hub you've added adds processing and memory overhead and does not add any value.
I created a simple sample app that uses a service that clients listen to for updates:
https://github.com/conficient/BlazorServerWithSignalR
Is there something special I need to define in an ASP.NET MVC application to read an incoming response from a ASP.NET Web API?
From my MVC app, I make a request to an ASP.NET Web API using System.Net.HttpClient. The API receives the request and processes it fine and returns a valid response. However, the MVC application, it appears, never gets the response. I have a break point on the line that makes the request. The flow of control never comes back after executing that line. The MVC app just keeps waiting and times-out after a very long time.
However, I can confirm that the API returns a valid Json response. I have tried composing this request in Chrome Postman and see that the API returns a valid response.
Here's the code from my MVC app that makes the request to the Web API:
public async Task<R> PostAsJsonAsync<T, R>(string uri, T value)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri(_baseUri);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.PostAsJsonAsync(uri, value);
if (response.IsSuccessStatusCode) return await response.Content.ReadAsAsync<R>();
else return default(R);
}
}
In the past, i.e. before Web API 2, I've had MVC apps talk to the Web API without any problem. I don't know if I am missing something that has been introduced in Web API 2.
I have a feeling you are getting a deadlock. Are you using .Result anywhere? You should be using async all the way. I mean your MVC action method should also be async method and they should await and not use .Result. Read this log post by Stephen Cleary for more info. http://blog.stephencleary.com/2012/07/dont-block-on-async-code.html
I have a web application which has few charts on dashboard. The data for charts is fetched on document.ready function at client side invoking a WCF service method.
What i want is now to use SignalR in my application. I am really new to SignalR. How can i call WCF methods from SignalR Hub or what you can say is that instead of pulling data from server i want the WCF service to push data to client every one minute.
Is there a way of communication between signalR and WCF service.
Also another approach can be to force client to ask for data from WCF Service every minute.
Any help will be really appreciated.
I have done following as of yet.
Client Side Function on my Dashboard page
<script src="Scripts/jquery.signalR-2.0.3.min.js"></script>
<!--Reference the autogenerated SignalR hub script. -->
<script src="/signalr/hubs"></script>
<a id="refresh">Refresh</a>
$(function() {
var dashboardHubProxy = $.connection.dashboardHub;
$.connection.hub.start().done(function() {
// dashboardHubProxy.server.refreshClient(parameters);
$("#refresh").click(function() {
dashboardHubProxy.server.refreshClient(parameters);
});
});
dashboardHubProxy.client.refreshChart = function (chartData) {
debugger;
DrawChart(chartData, 'Hourly Call Count For Last ' + Duration + ' Days', '#chartHourly', 'StackedAreaChart');
};
});
and my Dashboard Hub class is as follows
public class DashboardHub : Hub
{
private readonly ReportService ReportService = new ReportService();
public void RefreshClient(string parameters)
{
var chartData = ReportService.GenerateHourlyCallsTrendGraphicalReport(parameters);
Clients.All.refreshChart(chartData);
}
}
My SignalR startup class is as follows
[assembly: OwinStartup(typeof(CallsPortalWeb.Startup), "Configuration")]
namespace CallsPortalWeb
{
public static class Startup
{
public static void Configuration(IAppBuilder app)
{
ConfigureSignalR(app);
}
public static void ConfigureSignalR(IAppBuilder app)
{
app.MapSignalR();
}
}
}
When i click on refresh button and a debugger on RefreshClient method on hub the debugger doesn't get to the method which means i am unable to call server side method of SignalR.
Is there anything needs to be done in web.config?
I agree with AD.Net's comment. To elaborate slightly more though, the SignalR hubs can be hosted directly in your web project kinda the same way controllers are used. There is also a package out there so you can host the SignalR library on its own so it can act as a service all on its own. Either way you will need to hit the SignalR hub first as that is how it communicates then you would call your WCF service methods from within the hubs.
Brief explanation
Your HUB will have methods used by both your USER Client and your WCF Client. You may use something like UserConnected() for the user to call in and setup your logging of the connection. Then the WCF service may call your HUB with an UpdateUserStats(Guid connnectionId, UserStats stats) which would in turn call the USER client directly and provide the stats passed in like so Clients.Client(connectionId).updateStats(stats) which in turn would have a method on the USERS client named updateStats() that would handle the received information.
Initial page landing
What AD.Net provided is basic code that will be called when the user lands on the page. At this point you would want to log the ConnectionId related to that user so you can directly contact them back.
First contact with your hub touching WCF
From your Hub, you could call your WCF service as you normally would inside any normal C# code to fetch your data or perform action and return it to your user.
Method of updating the user periodically
SignalR removes the need for your client code to have to continually poll the server for updates. It is meant to allow you to push data out to the client with out them asking for it directly. This is where the persistence of the connections come into play.
You will probably want to create a wrapper to easily send messages to the hub from your application, since you are using WCF I would assume you have your business logic behind this layer so you will want the WCF service reaching out to your Hub whenever action X happens. You can do that by utilizing the Client side C# code as in this case your client is actually the user and the WCF service. With a chat application the other user is basically doing what you want your WCF service to do, which is send a message to the other client.
Usage example
You are running an online store. The dashboard displays how many orders there have been for the day. So you would wire up a call to the hub to send a message out to update the products ordered when a user places a new order. You can do this by sending it to the admin group you have configured and any admins on the dashboard would get the message. Though if these stats are very user specific, you will more then likely instead reach into the database, find the ConnectionId that the user has connected with and send the update message directly to that connectionid.
WCF Client Code Example
Just incase you want some code, this is directly from MS site on connecting with a .net client. You would use this in your WCF service, or wherever in your code you plan on connecting and then sending an update to your user.
var hubConnection = new HubConnection("http://www.contoso.com/");
IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");
stockTickerHubProxy.On<Stock>("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));
await hubConnection.Start();
Here is a link directly to the .Net Client section: http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-net-client
I am sure you have seen this link but it really holds all the good information you need to get started. http://www.asp.net/signalr
Here is a more direct link that goes into usages with code for you. http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-server
ADDED: Here is a blog specific to Dashboards with SignalR and their polling.
http://solomon-t.blogspot.com/2012/12/signalr-and-interval-polling-for.html
ADDED: Here is a page on managing users signalR connections.
http://www.asp.net/signalr/overview/signalr-20/hubs-api/mapping-users-to-connections
Update for your code update
The .Net Client library (in NuGet) gives your .net code access to the hub. Since you are a client you will need to connect to the hub just like the User who is also a client. Your hub would act as the server for this. So with the .Net Client I am assuming you would setup a windows service that would internally poll, or something event based that would call the .Net Client code portion of it which would reach out to your hub. Your hub would take the information provided, more than likely a ConnectionId or GroupId and broad cast the User (which is perhaps on a website so it would be the JS client) a method that would update the front end for the user client. Basically what I mention under "Brief Explanation".
Now, to directly respond to the code you posted. That is Javascript, I would expect a connect like you have done. Updating the chart on initial connection is fine as well. If this is all the code signalR wise though you are missing a client side method to handle the refresh. Technically, instead of calling Clients.Caller.RefreshChart() you could just return that data and use it, which is what your javascript is doing right now. You are returning void but it is expecting a your date.
Now, I would actually say correct your javascript instead of correcting the hub code. Why? Because having a method in JS on your client that is called "refreshChart()" can be reused for when you are having your server reach out and update the client.
So I would recommend, dropping anything that is related to updating the dashboard in your JS done statement. If you want to do a notification or something to the user that is fine but dont update the grid.
Now create a JS client function called "refreshChart", note the lower case R, you can call it with a big R in c# but the js library will lowercase it so when you make the function have it will receive your dashboard information.
Now, on the server polling, or executing on some action, your WCF would call a method on the hub that would be say "UpdateDashboar(connectionId,dashInfo)" and that method would then inside of it call the "refreshChart" just like you are doing in your RefreshClient method, accept instead of doing Clients.Caller you would use Clients.Client(connectionId).refreshChart(chartInfo).
Directly the reason your code is not working is because you need to turn that Void into the type you expect to be returned. If the rest is coded right you will have it update once. You will need to implement the other logic I mentioned if you want it constantly updating. Which is again why I asked about how you are persisting your connections. I added a link to help you with that if you are not sure what I am talking about.
You should use the SignalR Hub to push data to the client. Your hub can consume a WCF service (the same way your client can) to get the data.
from client:
hub.VisitingDashBoard();
on the hub in the VisitingDashBoard method:
var data = wcfClient.GetDashboardData()//may be pass the user id from the context
Clients.Caller.UpdateDashboard(data)
Of course your client will have a handler for UpdateDashboard call
We have a Flex client and a server that is using the Spring/Blazeds project.
After the user logs in and is authenticated, the spring security layer sends a redirect to a new URL which is where our main application is located.
However, within the flex client, I'm currently using HTTPService for the initial request and I get the redirected page sent back to me in its entirety.
How can I just get the URL so that I can use navigatetourl to get where the app to go where it needs to?
Any help would greatly be appreciated. Thanks!
One solution would be to include a token inside a comment block on the returned page, for instance:
<!-- redirectPage="http://localhost/new-location" -->
then check for it's presence inside the HTTPService result handler. The token's value could then be used in your call to navigateToURL.
Another solution would be to examine the HTTP response headers and extract the value of the "Location" header using ActionScript. Consider using the AS3 HTTP Client lib.
From the examples page http://code.google.com/p/as3httpclientlib/wiki/Examples To determine the 'Location' header from the response:
var client:HttpClient = new HttpClient();
var uri:URI = new URI("http://localhost/j_security_check");
client.listener.onStatus = function(event:HttpStatusEvent):void {
var response:HttpResponse = event.response;
// Headers are case insensitive
var redirectLocation:String = response.header.getValue("Location");
// call navigateToURL with redirectLocation
// ...
};
// include username and password in the request
client.post(uri);
NOTE: AS3 HTTP Client depends on AS3 Core and AS3 Crypto libs.
You can also simply use the URLLoader class, no need for external code. One of the events it dispatches is HTTPStatusEvent.HTTP_RESPONSE_STATUS. Just plug into that and retrieve the redirected url:
urlLoader.addEventListener(HTTPStatusEvent.HTTP_RESPONSE_STATUS, onHTTPResponseStatus);
private function onHTTPResponseStatus(event:HTTPStatusEvent):void
{
var responseURL:String = event.responseURL;
}
I am (successfully) using this code right now, so if it doesn't work for some reason, let me know.
I am new to web services. The last time I dealt with SOAP was when I created a bunch of wrapper classes that sent requests and received responses back per some response objects/classes I had created. So I had an object to send certain API requests and likewise a set of objects to hold the response back as an object so I could utilize that 3rd party API.
Then someone came to me and said why not just use the wsdl and a web service. Ok, so today I went and created a "Service Reference". I see that this is what's called a "Proxy Class". You just instantiate an instance of this and then walla you have access to all the methods from the wsdl.
But this leaves me with auth questions. Back when I created my own classes manually, I had a class which exposed properties that I would set then access for things like signature, username, password that got sent along with the Http request that were required by whatever 3rd party API I was using to make API calls.
But then with using a Service Reference, how then would I pass this information just like I had done in my custom classes? For instance I'm going to be working with the PayPal API. It requires you to send a signature and a few other pieces of information like username and password.
// Determins if API call needs to use a session based URI
string requestURI = UseAuthURI == true ? _requestURIAuthBased + aSessionID : _requestURI;
byte[] data = XmlUtil.DocumentToBytes(doc);
// Create the atual Request instance
HttpWebRequest request = CreateWebRequest(requestURI, data.Length);
So how do I pass username, password, signature, etc. when using web service references for each method call? Is it as simple as specifying it as a param to the method or do you use the .Credentials and .URL methods of your proxy class object? It seems to me Credentials means windows credentials but I could be wrong. Is it limited to that or can you use that to specify those required header values that PayPal expects with each method call/API request?
Using Web Service or Web Service Reference