Would it be better in terms of clean architecture to have a separate service class that calls the api? or its it better off in the blazor component file itself
Tim, A lot of things have change with Webasembly especially in this area. I pretty sure this can be done ASP.Core Host server, it much more different related to HtmlClient. I want this work in something I am working - my quests it probably related to client is not actually a core project. When you research Webassembly, please research HtmlClient example here and with that project. One big difference there is no startup.cs
Base on Microsoft docs - I try the following replacement in program.cs string uri = "www.metaweather.com/api/"; var builder = WebAssemblyHostBuilder.CreateDefault(args); builder.RootComponents.Add("app"); builder.Services.AddTransient(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) }); builder.Services.AddHttpClient("ServerAPI", client => client.BaseAddress = new Uri(uri)) .AddHttpMessageHandler(); builder.Services.AddTransient(sp => sp.GetRequiredService() .CreateClient("ServerAPI")); await builder.Build().RunAsync();
I need to consume an endpoint that returns a JSON array (that is, the JSON text starts with a '['-character). Generating the model from JSON with "Paste Special" works fine. However, because the received JSON represents an array and not a single object, I think that "Paste Special" is doing it wrong when it generates a *single* Rootobject (with an array inside of it). And obviously it doesn't work either, because the *ReadFromJsonAsync()* throws an exception on the first JSON character it sees (the '['). Is there a trick that I can use to consume the JSON anyway?
I think I found the answer myself: Just disregard the genereted *RootObject* class and do a *ReadFromJasonAsync()* instead (where *Class1* is the generated type of the objects inside the JSON array)
@@martinchristiansen556 Thanks, this might fix the issue I'm having too. I was trying to pull in a JSON RootObject that contains a list of objects but I guess I just need to read directly into the list.
The new System.Text.Json package is faster, so if you are able to use it and don't need the more advanced features of Newtonsoft, I would recommend going that way.
29:37 Hi Tim Great Video again!! Its great help in my journey to learn Blazor and C#. I was trying to see if I can get the 'Title' and 'Timezone' but not able to figure it out...
Are you saying those two properties are empty or that you don't know how to display them? If the former, check the spelling of the properties. If the latter, follow the pattern of what I did for the other properties.
I recommend a couple of my videos for this - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DwbYxP-etMY.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ub3P8c87cwk.html
Hi Tim, Hope you are well. Is it possible to have a video what happening behind during dependency injection. If I'm not wrong I think there are so many things we can do using dependency injection while configuring services. I would love to learn more about that. Thanks.
What strategy do you suggest for clients generated by NSwag which is default for scaffolding REST API Clients in NET Framework in Visual Studio? It accepts HttpClient as an argument. Do you suggest creating one such client everytime (short lived, such as DbContext with EF Core) and populating it with a HttpClient received from IHttpClientFactory? The problem is that the NSwag-generated client accepting HttpClient in constructor does not implement IDisposable. How to work with that?
Hi Tim, When we use Multiple named http client, is there any way we can assign the common properties in single place instead repeating in all the named http clients? Thanks in advance
Hi Tim, I tried this except using the WebAssembly project and ran into CORS issues that I haven't been able to resolve. I'm not sure where the issue needs to be corrected. I ran the source linked above and it does work for me so it seems to be a webassembly specific issue.
Nope. It is an option but it is not going to become the only option. In general, you will not find any languages or systems that "kill" all of the rest. There are just too many scenarios for one solution to fit well.
Hi Tim, would this method work for calling an API that is a completely separate app? From debugging the code I have noticed that my "client" is NULL therefore I believe my Blazor App is not finding the URI that is supplied! Tried several different techniques but to no avail. I have looked thru MS documentation, watched this video several times while taking notes and viewed videos from Nick Chapass /Raw Coding but neither are using separate apps. Any help from yourself or other pupils would be appreciated. Thanks.
would be good , if you have some video on HttpClient(POST) , with some advanced concepts like sending IFormFile in post request , send parameters to post request
Hi Tim, I have a very important question. The problem with IHttpclientFactory is that when used for a service like in blazor, it always creates a Transient, Service. But most of the time we want the service to be Scoped as an example to make it clearer. With Httpclient we write for a scoped service in program.cs of the client.WASM in NET6. builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) }); builder.Services.AddScoped(); which is scoped fine. But with IHttpclientFactory we would have builder.Services.AddHttpClient(client => { client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress); }); Which is transient which is not what we want! we want it scoped when injected in a component. How can we make this IHttpclientFactory create a scoped service here for (IProductService, ProductService)!!? The' easiest way possible?!! Thank you for your help.
You might need to stick with HttpClient for that (see the docs here: learn.microsoft.com/en-us/dotnet/core/extensions/httpclient-factory#httpclient-lifetime-management ). If that doesn't explain it well enough, you probably need to ask this question on Stack Overflow.
How do you deal with making API calls to a SQL Server instance hosted locally? I'm using EF Core and EF SQLServer and can get it to work locally when debugging, but for some reason get the 500 Server error when hosting it on IIS and accessing it through a client browser. Any thoughts?
I am not sure where in your configuration you have an issue, but something isn't set up right. Maybe your website needs to have the connection string updated. Maybe there is a permissions issue with the username and password in the connection string. Maybe the issue is somewhere else entirely.
It is not clear to me why you use System.Net.Http.Json instead of Microsoft.AspNet.WebApi.Client as you did in a previous video on api calls... What's the difference? Why use one instead than the other? Which one should we use?
Those are two different libraries. We are using Http.Json to handle translating the data from and to JSON. WebApi.Client does a lot more with connecting to the web. It isn't something we need in this instance.
Lets assume you have an WebAPI which references Services layer (class library) that handles all the logic. If you inject IHTTPClientFactory to the WebAPI all is fine, but how do you pass the HTTPClientFactory to the service layer so one is able to do calls from there? A class library doesn't know about IHTTPClientFactories and such.
WebAPI is the API itself (the project that sends data to anyone who calls it - swapi.dev is an API). HttpClient is the utility in C# to call an API and get the data.
Hello, i have my solution structured like Client -- Server -- Shared, I have to somehow access the HttpClient on my server project in my Client project to reach IHttpClientFactory, anyway to resolve this?
Those are separate projects. You cannot access a class instance across those projects. You will need to create a IHttpClientFactory on your client project as well, not just on your server project.
They were teaching us Ada & Fortran at USC back in the 80s when the industry was using C & Visual Basic! Thank god, I was working in the industry more than going to class back then. I'm a big believer of learning computer science and software development online instead of in schools.
@@mrcalico7091 Feels like it's now happening as the trend that will change the surface of an education methods dramatically. Those days when online courses have been looking just like the way to spend time are almost gone.
Nice info. I think the next step would be to refactor the httpclient code out of the razor page into a weatherService class that does all that work, and inject the weatherService into the razor page to keep your layers and responsibilities de-coupled.
Thanks for the video, Tim. I would like to know how to configure the proxy server to consume the API through it. I'm getting Authentication error in the exception message ( Response status code does not indicate success: 407 (Proxy Authentication Required)). How do that with HttpClient?
To get properly named json to c# classes you can get them from quicktype.io/csharp/. Then just change the JsonProperty to JsonPropertyName, and add the System.Text.Json.Serialization reference. Thanks for the video Tim.
Because the US is backwards. We cling to 32 degrees as freezing, 212 degrees as boiling, 5,280 feet in a mile,12 inches in a foot, etc. Doesn't that sound simpler? 😂
var client = _clientFactory.CreateClient(); Throws Nasty error 'Value cannot be null. (Parameter 'factory')' Added services.AddHttpClient(); to ConfigureServices SAME ERROR
How do you have a named client and also use a certificate? Without a factory, I would just create a HttpClientHandler and add the client certificate. Then add the handler to the client on creation. Additionally, how would you reset this client to a new certificate without restarting the app?
Thanks! I want to create a project for hands-on, but was banging my head on stackoverflow and ms documentations, got this great resource, you are doing a great job.👍
Great video, I managed to get my WebAssy app to call API working using this. Definitely had issues with CORS as you mentioned. Also need to see how to send with JWT auth. Also had issue getting config from the program.cs in the WebAssy app (no startup.cs). So I'll be looking forward to another video with a WebAssy app that covers all this. Thanks!
Thanks tim i will watch this later tonight ,Blazor is amazing especially the client version the only thing bugging me is the CSS isolation hope they will add the feature soon, is it possible to share with us the course that you will publish next here on youtube or on your website ?
Tim. You're a Godsend. I recently spent a couple of hours writing classes for deserializing large json files. My heart sand when you pulled down the menu to convert json to classes. ! Now I have to write code to deal with multiple different devices with httpclient. I am not using DI , primarily because I don't fully understand it or how it applies to a C# WPF prog like I am developing. This was very helpful. I always love it when something I don't expect pops up in your vids. Thanks again.
Is there an elegant way of adding query string parameters to attach to the GET request, or is it best to build the full URL manually with something like stringbuilder?
Hi Tim can you please be so kind and help me with my API? I followed your Video step by step, but for some reason it didn't work. Every time I open the Page, i get the following error message: JsonReaderException: '
You are trying to read a page as JSON but it appears that the page is sending back either XML or HTML. Check the contents of the page you are trying to parse.
Thank you for the video Tim. Can you make a video how to use properly HttpClient in a project that has not built-in dependency injection, e.g. Console App, WPF App or Windows Service?
Ah, the joys of RU-vid when you search for how to call an old SOAP webservice in Blazor and you're a way into the suggested video before you realise that's not what's being explained at all and you've wasted time you don't have.
Bummer. You could probably take the new ways of talking to HttpClient from this video and combine it with the answer to this Stack Overflow question: stackoverflow.com/a/20108971/733798
I connect my third party API to web application and the performance is too slow. For that I need to make web service in back-end and call on demand from front end. Can you please guide me on that?
Thanks Tim. I wonder how would you overcome that underscore issue in a layered architecture where your DTO or a model would be a part of domain/core and api fetching service a part of Infrastructure layer? Since we can change weather api provider, there should be some mapping involved? Or am I looking at this from the wrong angle? I’d just prefer my models and DTOs to remain POCO.
I am not sure I see the issue. If your DTO needs to change based upon a higher layer, you would do a mapping to a new model. Does that answer your question?
@@IAmTimCorey Yeah, that's what I figured. What I wanted to ask, for an example in EF, you could decorate your entities, but if you prefer not to, you can specify decoration equivalents in the configuration. That way you can map things outside of the entities and have them remain completely oblivious of EF. IF you then switch to a different ORM, you just (hopefully) write new configuration specific to that ORM. Is there any way to do something similar with JSON deserialization using System.Net.Http.Json ? Hope this clears it up. Thanks, Tim.
The video is very useful but i am getting "The JSON value could not be converted to Domain model" while converting the service response client.GetFromJsonAsync(employeeCache
Tim, first of all thank you for all the great tutorials! My job schedule is very demanding but I am able to find 20 minutes here and 30 minutes there to follow them. Do you have an ordered index of all the videos? It would be great to go though them in the proper order, right now I am guessing from the names and upload dates.
Can we consume an webapi in another webapi?? How can we create a request headers with basic authentication and client cert in consuming webapi request??
Sure. An API is just a C# application so it can do basically everything any other C# application can do behind the UI. So the calls would be no different than if we were making them from WPF or Blazor Server.
Hi Tim, Great Job! I just found your channel and will be a regular from now on. I see in some of the comments there was mention of a video showing how to POST data. Have you posted one of those yet?
Correct, it is not free. I have also not found the need to use a third-party solution when Visual Studio does everything I need. I often find that people look for "better" tools without first learning how to use the tools they have.
Great tutorial Tim. However how do I add httpclientfactory in a caliburn micro wpf bootstrapper.? The simple container singleton does not allow for the implementation of the client factory.
Sir tim is it advisable to inject a type client to the page instead of httpclient factory?. the type client implement the httpclient on the constructor. Thank you for these kind of great videos, you motivate me a lot.😊👍☝️
@@IAmTimCorey can you help me . I receive this error : "The operation was canceled." My code: public async Task PostPaid([FromBody] object ob) { String rep = ""; User d = JsonConvert.DeserializeObject(ob.ToString()); try { var vm = new { username = d.Login, password = d.Pwd }; //WinHttpHandler httpHandler = new WinHttpHandler(); //httpHandler.SslProtocols = SslProtocols.Tls12 | SslProtocols.Tls11 | SslProtocols.Tls; // HttpClient client = new HttpClient(httpHandler); using (HttpClient client = new HttpClient()) { client.DefaultRequestHeaders.Add("Accept", "application/json"); var httpRequestMessage = new HttpRequestMessage { Method = HttpMethod.Post, RequestUri = new Uri(d.MyUrl), Content = new StringContent(JsonConvert.SerializeObject(vm)) }; httpRequestMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json"); HttpResponseMessage result = await client.SendAsync(httpRequestMessage); rep = await result.Content.ReadAsStringAsync(); } } catch (Exception ex) { return Json(ex.Message); } return Json(rep); }
you talked about doing a Blazor Wasm video, it would be cool if you could do one with Azure Static Web App Preview. This new service is setup for the many common JavaScript frameworks, but Tim Heuer (@TimHeuer) did one with Blazor Wasm. To get live data you would need to create Azure Functions. Anyway thanks for the video
Maybe I missed it, but where is the OnInitializedAsync() coming from? I was wondering the same thing, and sure enough, it's underlined on my computer because it can't find the thing to override? Is this a Blazer/Razer only thing?
