Reactjs - Can't trigger ASP Controller from react with fetch

MrBool
December 30, 2023
247 views
2 votes
3 Answers

Good day together,

I try to trigger a ASP Controller from React. I tested many different things.But nothing works.
Sometimes I get the message in browser that routes does not exist (I try many routes) or "No routes matched location "/DataController/alldata". The last time I get the message "Enable to verify the first certificate".(From Postman)
Please help me. I sit on this Problem already to long 😉

Merry Christmas and go happy new year.

The current code:

ASP Controller

[Authorize]
[ApiController]
[Route("[controller]")]
public class DataController : Controller {
...


[HttpGet]
[Route("alldata")]
public IActionResult GetData(){
var data = new {key1="test1", key2="test2"};
return Ok(data)
}

React Code (fetch)

export const GetDataset = function () {
const fetchData = async() => {
try {
 const result = await fetch('https://localhost:port/DataController/alldata')
 const jTest = await result.json();
 
}catch(error){
.....
}
}
fetchData()
}

React Component Call

componentDidMount() {
 GetDataset();
}

Answers

- juunas
- December 27, 2023 at 12:41 pm
- 0 votes
0
When you use [controller] in the route, that means the name of the controller class minus the word Controller.

So your URL should be something like: https://localhost:port/Data/alldata.

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- ajdinbulut
- December 27, 2023 at 1:32 pm
- 0 votes
0
Can you try adding this to your program.cs file:
```
app.UseAuthentication();
app.UseAuthorization();
```
Note that it has to be in that order.
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I tested many different things.But nothing works. Sometimes I get the
message in browser that routes does not exist (I try many routes) or
"No routes matched location "/DataController/alldata".

Well, based on your shared code snippet and description, I have tried to reproduce your issue, and was I able to hit the controller endpoint and got the response accordingly.

Altough, your code seems alright and I have just omitted the [Authorize] because I don’t need that in order to execute my testing scenario. Its working accordingly.

Here is the steps I did, for calling he API from the react endpoint:

Controller:

Almost same as yours:

    [Route("[controller]")]
    [ApiController]
    public class DataController : ControllerBase
    {
        [HttpGet]
        [Route("alldata")]
        public IActionResult GetData()
       {
            var data = new { key1 = "test1", key2 = "test2" };
            return Ok(data);
        }
    
    }

Program.cs file:

In the program.cs file I have configured the CORS setting:

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();


builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowOrigin",
        builder => builder.WithOrigins("YourReactEndpoint")
                          .AllowAnyHeader()
                          .AllowAnyMethod());
});

var app = builder.Build();
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseAuthorization();
app.UseCors("AllowOrigin");
app.MapControllers();

app.Run();

React Testing Code:

I have used below approach in react for quick test:

import React, { useEffect, useState } from 'react';

export function App(props) {
  const [data, setData] = useState(null);
  const [error, setError] = useState(null);

  useEffect(() => {
  const fetchData = async () => {
    try {
      const response = await fetch('https://localhost:7299/Data/alldata');
      if (!response.ok) {
        throw new Error('Network response was not ok');
      }
      const result = await response.json();
      console.log(result);
      setData(result);
    } catch (error) {
      setError(error);
    }
  };

  fetchData();
}, []);

  return (
    <div className='App'>
     
    </div>
  );
}

Output: