In my application i need to implement verification if user has entered correct login and password or not. the login and the password are stored at the web server so i have to organize correct connection to the server. I'm an absolute beginner in everything about http requests and all that stuff. Actually i downloaded ASIHTTPRequest library and added it to my project just yesterday. My main problem is that i don't have an actual server by now (and i' m using just a conventional URL which later will be replaced with true server name but i want my code to be correct already)so i cannot test myself whether i'm doing things correctly or not.So my questions are:
1)What is the best way to organize verifying user's login and password? Should i use synchronous request or asynchronous? For all i know synchronous requests are rare in use cause they stop the application while the request is being performed but there's really nothing else needed to be done in this event so i'm a bit confused.What would you use?
2)I suppose verifying user's login and password by using http requests is pretty common task so there must be a general rule what kind of data the web server returns. I don't want to invent a wheel. should i use NSString returned by responseString to check if user's login and password match? What does server returns usually in such cases? How should my code look like? Something like
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:someUrl];
[request startSynchronous];
NSString *response = [request responseString];
if ([response isEqualToString:@"login and password match"])
//user enters next screen
else
//user is notified about the error
or something else? What would you do?
3)This request is not only i need to implement. Later i'm going to connect to the same URL with a different request. So how does the server know what kind of request is currently being used?
I really need your advice. Great thanks in advance
I have tried to answer your question,
Q:1. Synchronous or Asynchronous request model for login?
-> As per apple's documentation
A synchronous load is built on top of the asynchronous loading code made
available by the class. The calling thread is blocked while the asynchronous
loading system performs the URL load on a thread spawned specifically for
this load request.
also,
NSURLConnection provides support for downloading the contents of an NSURLRequest in a synchronous manner using the class method sendSynchronousRequest:returningResponse:error:. Using this method is not recommended, because it has severe limitations:
The client application blocks until the data has been completely received, an error is encountered, or the request times out.
Minimal support is provided for requests that require authentication.
There is no means of modifying the default behavior of response caching or accepting server redirects.
As you are unaware of server side implementation, which may involve:
1. Redirection and other mechanisms for fulfilling the request.
2. It may require some proxy authentication or other similar stuff.
Q:2. What does server returns usually in such cases?
In general, a web service is implemented at server-side which returns XML or JSON as repsonse which you have to parse and use. example response may look like:
for XML:
<auth>
<statusCode>0</statusCode>
<statusMessage>Login Successful.</statusMessage>
</auth>
for JSON
{
"statusCode" = "0"
"statusMessage" = "Login Successful."
}
tags(for XML) and keys(for JSON) will depend upon you sever implementation.
3. How does the server know what kind of request is currently being used?
-> The URL which you will use for request will tell server, what you are looking for?
for example
http://www.example.com/mywebapp/getItem?id="1";
Thanks,
or
http://www.example.com/mywebapp/removeItem?id="1";
The bold path item represents services which you are calling.