The input was not valid .Net Core Web API
I am facing a weird issue and almost spent 4 hours with no luck.
I have a simple Web API which I am calling on form submit.
API-
// POST: api/Tool
[HttpPost]
public void Post([FromBody] Object value)
{
_toolService.CreateToolDetail(Convert.ToString(value));
}
HTML-
<!DOCTYPE html>
<html>
<body>
<h2>HTML Forms</h2>
<form name="value" action="https://localhost:44352/api/tool" method="post">
First name:<br>
<input type="text" id="PropertyA" name="PropertyA" value="Some value A">
<br>
Last name:<br>
<input type="text" id="PropertyB" name="PropertyB" value="Some value B">
<br><br>
<!--<input type="file" id="Files" name="Files" multiple="multiple"/>-->
<br><br>
<input type="submit" value="Submit">
</form>
</body>
</html>
When I hit the submit button I get below error-
{"":["The input was not valid."]}
Configurations in Startup class-
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
services.AddSingleton<IConfiguration>(Configuration);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseMvc();
}
This only happens for POST request. GET request works fine. Same issue when testing in Postman REST client. Any help please? Please let me know if I can provide more details.
Answer
Don't use FromBody. You're submitting as x-www-form-urlencoded (i.e. standard HTML form post). The FromBody attribute is for JSON/XML.
You cannot handle both standard form submits and JSON/XML request bodies from the same action. If you need to request the action both ways, you'll need two separate endpoints, one with the param decorated with FromBody and one without. There is no other way. The actual functionality of your action can be factored out into a private method that both actions can utilize, to reduce code duplication.