C#•13mo ago

Requests

Hello, i have never done something that i will say before, how can i send a request to an API Url, get responce in a form of a .json file and then getting specific values from the .json into variables. How can i do that?

77 Replies

Angius•13mo ago

HttpClient Then .GetFromJsonAsync<T>() Where T is a class that represents the JSON response

PixxelKick•13mo ago

Is the API returning a json file or a json response? Json File you'll need to handle slightly different as it's a text file which has a small bit of headers and you need to open a stream reader, I think? I want to say a text file cant be read exactly the same way as a raw byte stream of text, the file has a little bit of stuff at the start to go "Im a file!"

BlazeOP•13mo ago

json responce

PixxelKick•13mo ago

oh then thats easy yeh, what Z23Z said is 👍

BlazeOP•13mo ago

how could i pass data into httpclient

Angius•13mo ago

What data?

PixxelKick•13mo ago

https://learn.microsoft.com/en-us/dotnet/api/system.net.http.httpclient?view=net-8.0&viewFallbackFrom=dotnet-aspire-8.0

Angius•13mo ago

A GET request has no body, only query parameters

BlazeOP•13mo ago

for exaplme the api im using requires username + password to be passed in order to get a valid login token

Angius•13mo ago

Ah, a POST request then .PostAsJsonAsync<T>(url, data)

PixxelKick•13mo ago

is it FormContent or Body or Url Params?

BlazeOP•13mo ago

"Content-Type: application/json" body

PixxelKick•13mo ago

Body, aight

BlazeOP•13mo ago

var client = new HttpClient();

var pairs = new List<KeyValuePair<string, string>> {                 
    new KeyValuePair<string, string>("username", "username"),
    new KeyValuePair<string, string>("password", "password")
};
var content = new FormUrlEncodedContent(pairs);

var response = client.PostAsync(URL_LOGIN, content).Result;

if (response.IsSuccessStatusCode) {
    string _data = await response.Content.ReadAsStringAsync();
}

var client = new HttpClient();

var pairs = new List<KeyValuePair<string, string>> {                 
    new KeyValuePair<string, string>("username", "username"),
    new KeyValuePair<string, string>("password", "password")
};
var content = new FormUrlEncodedContent(pairs);

var response = client.PostAsync(URL_LOGIN, content).Result;

if (response.IsSuccessStatusCode) {
    string _data = await response.Content.ReadAsStringAsync();
}

So something like this?

PixxelKick•13mo ago

FormUrlEncodedContent is for when it has to be submitted as FormContent PostAsJsonAsync is when it has to be submitted as just application/json in the body

BlazeOP•13mo ago

httpclient.PostAsJsonAsync? ah just needed to add a reference to http.formating altho im confused on what type the "value" has to be

Angius•13mo ago

class PostData
{
    [JsonProperty("username")]
    public string Username { get; init; }
    [JsonProperty("password")]
    public string Password { get; init; }
}

class PostData
{
    [JsonProperty("username")]
    public string Username { get; init; }
    [JsonProperty("password")]
    public string Password { get; init; }
}

var client = new HttpClient();

var data = new PostData {
    Username = ...,
    Password = ...,
}
var response = await client.PostAsJsonAsync(url, data);
var responseData = response.ReadFromJsonAsync<SomeClass>();

var client = new HttpClient();

var data = new PostData {
    Username = ...,
    Password = ...,
}
var response = await client.PostAsJsonAsync(url, data);
var responseData = response.ReadFromJsonAsync<SomeClass>();

SomeClass being a class that describes the data you get from the endpoint

BlazeOP•13mo ago

okay thanks also if you dont mind how can i enable cs9+ , i cant find <LangVersion> inside my .csproj

Angius•13mo ago

What's the framework version you're using?

BlazeOP•13mo ago

i find that in .csproj?

Angius•13mo ago

Yep

BlazeOP•13mo ago

4.8

Angius•13mo ago

Oof Why not use a recent version of .NET instead?

BlazeOP•13mo ago

idk xD i never got to update it +idk how to do it

Angius•13mo ago

You probably created a project with .NET Framework instead of .NET For reference, $newproject

MODiX•13mo ago

When creating a new project, prefer using .NET over .NET Framework, unless you have a very specific reason to be using .NET Framework. .NET Framework is now legacy code and only get security fix updates, it no longer gets new features and is not recommended. https://cdn.discordapp.com/attachments/569261465463160900/899381236617855016/unknown.png

BlazeOP•13mo ago

never touched those things

Angius•13mo ago

Did you not create this project, then?

BlazeOP•13mo ago

aight lemme remake my project i did but i used .net framework

Angius•13mo ago

Well, shouldn't have

BlazeOP•13mo ago

dw i didnt go much into it aigh so i got 7.0 rn

Angius•13mo ago

8.0 is current Might have to update VS to use it, tho

BlazeOP•13mo ago

hm gimme a sec i updated it, we will talk tmr if thats fine i have to do smt rn

PixxelKick•13mo ago

I wish "paste json as class" automated this, hopefully eventually this becomes a thing

BlazeOP•13mo ago

@ZZZZZZZZZZZZZZZZZZZZZZZZZ ive got the framework on my project how do i enable cs 9 now?

Angius•13mo ago

If you have a .NET 8 project, you should be on C# 12 from the get-go

BlazeOP•13mo ago

ah okay tyty

BlazeOP•13mo ago

ive never met this error before:

BlazeOP•13mo ago

i mean i did but i do not understand it

Angius•13mo ago

You need the extension method from... uh, whatever namespace See if quick fixes fix it

BlazeOP•13mo ago

ah okay

Angius•13mo ago

System.Net.Http.Json is where thos extension methods are

BlazeOP•13mo ago

now it doesnt show up in COM oh okay there was http.extentions one installed it and included it still doesnt fix it

Angius•13mo ago

Wym "installed"? It's not a nuget, no need to install anything

BlazeOP•13mo ago

it is its not in the COM list for me

BlazeOP•13mo ago

installing this fixed it

Angius•13mo ago

Huh, maybe it is, then

BlazeOP•13mo ago

before i installed the latest vs i didnt have to install it, cus i installed a package requireing it before which prob installed it @ZZZZZZZZZZZZZZZZZZZZZZZZZ sorry for the ping, i stopped working on this for some time as of irl stuff, how do i get the data from the class inputed into ReadFromJsonAsync<>();?

Angius•13mo ago

The example you mentioned is how There isn't anything more to it

BlazeOP•13mo ago

im confused lmfao what example did i mention

Angius•13mo ago

My message you replied to

BlazeOP•13mo ago

i got my "responeData" i got that but how do i get the value that has been returned from the response

Angius•13mo ago

From responseData

BlazeOP•13mo ago

like my class has a int Token, how do i get that Token from responseData

Angius•13mo ago

The SomeClass class should describe the data you expect to receive

BlazeOP•13mo ago

yeah ive got that

Angius•13mo ago

So if you expect to receive

{
    "status": "running",
    "count": 67162,
    "identifier": "781b-1-3bb2-1"
}

{
    "status": "running",
    "count": 67162,
    "identifier": "781b-1-3bb2-1"
}

you will have a class

class MyCoolData
{
    [JsonProperty("status")]
    public string Status { get; init; }
    [JsonProperty("count")]
    public int Count { get; init; }
    [JsonProperty("identifier")]
    public string Identifier { get; init; }
}

class MyCoolData
{
    [JsonProperty("status")]
    public string Status { get; init; }
    [JsonProperty("count")]
    public int Count { get; init; }
    [JsonProperty("identifier")]
    public string Identifier { get; init; }
}

and after getting the data from the stream

var responseData = await response.ReadFromJsonAsync<MyCoolData>();

var responseData = await response.ReadFromJsonAsync<MyCoolData>();

you can get the status with

var s = responseData.Status;

var s = responseData.Status;

BlazeOP•13mo ago

yea but how do i get the value of "Count" for example from responseData

Angius•13mo ago

responseData.Count

BlazeOP•13mo ago

i did that with my "Token" variable but it wasnt under responsedata

Angius•13mo ago

MyCoolData responseData = await response.ReadFromJsonAsync<MyCoolData>();

MyCoolData responseData = await response.ReadFromJsonAsync<MyCoolData>();

this might be easier to understand

BlazeOP•13mo ago

tyty, im getting status 443 from the api url, it means that the url endpoint doesnt exist?

Angius•13mo ago

I don't remember every status code by heart Look up what it means on MDN

BlazeOP•13mo ago

Angius•13mo ago

Notice your lack of await

BlazeOP•13mo ago

im blind sorry fr this time late night coding 10/10 would not recommend im confused, out of nowhere it throws an "System.Text.Json.JsonException: ''I' is an invalid start of a value. Path: $ | LineNumber: 0 | BytePositionInLine: 0.'" from System.Text.Json.JsonException, i didnt touch that part of my code, google search did not help

Angius•13mo ago

What's the actual response you get from the API? Run it via some REST client like Bruno or Nightingale Or even just open it in the browser Chances are, that for some reason what you get from that URL isn't valid JSON

BlazeOP•13mo ago

how can i pass the json parms trought tho

Angius•13mo ago

Right, that's why I mentioned using some client You can pass params there at will Alternatively, read the response as a string and log it to the console

BlazeOP•13mo ago

ill extract the response into a plain text file

Angius•13mo ago

That'll do in a pinch as well Yeah

BlazeOP•13mo ago

i get returned "Internal Server Error" as plain string text, an issue of the api was already created on github but closed ill make anothjer one

Angius•13mo ago

Ah, that'll do it, yeah Might want to check the response status first, before trying to deserialize it

BlazeOP•13mo ago

i think its 505

Angius•13mo ago

That way you can actually tell that an error has occured instead of crashing the app

BlazeOP•13mo ago

nvm i have trycatch dw Yeah ill try tmr some poeple were saying they get same issue around same time.

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