Understanding [HttpPost], [HttpGet] and Complex Actionmethod parameters in MVC

Question

I am very very new to MVC the design-pattern and also the Framework. I am also not extremely well- versed in fundamentals of ASP.NET Forms. However, I do understand the basi

Answer 1

Generally, complex objects are passed in the HTTP body with verbs that support it such as POST and PUT. The body content must pass Model Binding validation. That basically means that if it's a POST request with Content-Type: application/json, it must deserialize from JSON into MyViewModel. If the content is XML, it must deserialize as XML.

General convention is to have all the primitive types that can be found in the URL path, query, and headers first, then one complex type from the POST (or PUT) body after that. I believe it's possible to put complex types elsewhere, but then you're getting into type converters and custom attributes which you should probably hold off on if you're a beginner.

Why is this second method adorned with [HttpPost] when the first method does not require any attributes? Are there any guidelines on when to use [Http] attributes and when not?

"[HttpPost]" is telling the routing engine that this method overload is only available via HTTP POST. Attempting to PUT /home/index with a body will fail with 404 Not Found, in this case. The parameter-free version of Index() doesn't require it because it can work with any HTTP verb, including GET, POST, and PUT.