Question

I’m working on an app that asks the user to login to access some of his infrmations. I have a login.php file that is store on the server and all the usernames and passwords on the database.

On my app i have 2 uitextfields one for the username and one for the password. I understand that i can use the POST method to pass on the input to the web server and check wether the username and password match to then load the rest of the data. This is where am having trouble, can anyone help me with it, how do i pass on the inputs from the uitextfield to that web service to run the long.php script?

Answer 1

Skram’s answer is correct, although you might be thinking what is ASIHTTPRequest?

You can get the framework here:
ASIHTTPrequest home

Here is a short beautiful tutorial on how to use it:
Awesome Tutorial

And here is some code I used to do a login some time ago:

  -(IBAction)doLogin{

//make sure you have text in the username field, this is optional
if(![[username text] isEqualToString:@""]){
    //URL of your web service 
    NSURL *url = [NSURL URLWithString:@"http://localhost:8888/myservice.php"];
    //instantiate request object with URL
    ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
    //Set post values before you send it off (forcing password to lowercase)
    [request setPostValue:[[self.password text] lowercaseString] forKey:@"password"];
    [request setPostValue:[username text] forKey:@"email"];
    //this is optional, I have switch controlling what methods are called in the web service 
    [request setPostValue:@"2" forKey:@"method"];
    //set the delegate to self for ASIHTTPRequest delegates (things you'll see in the tutorial)
    [request setDelegate:self];
    //send out request
    [request startSynchronous];


    //Now this code handles what happens after the web service call, notice I use a dictionary called user info to hold the response and I check the string to verify pass or fail and act accordingly.

    NSString *verify = [NSString stringWithFormat:@"%@",[userinfo objectForKey:@"verify"]];
    if([verify isEqualToString:@"pass"]){
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:
                            @"MainStoryboard_iPhone" bundle:[NSBundle mainBundle]];
        UITabBarController *mainMenu = 
        [storyboard instantiateViewControllerWithIdentifier:@"mainMenu"];

        [self.navigationController pushViewController:mainMenu animated:YES];
    }
    else{
        //show login failed Dialog or something...
    }
}}

Here some more code, this is what happens when the server returns a response.

- (void)requestFinished:(ASIHTTPRequest *)request{       
if (request.responseStatusCode == 400) {
    NSLog(@"Something is wrong");        
} else if (request.responseStatusCode == 403) {
    NSLog(@"Something is wrong");
} else if (request.responseStatusCode == 200) {
    //the response code is good so proceed.
    NSString *responseString = [request responseString];
    userinfo = [responseString JSONValue];
        NSLog(@"%@", [userinfo objectForKey:@"id"]);
        NSLog(@"%@", [userinfo objectForKey:@"user"]);
        NSLog(@"%@", [userinfo objectForKey:@"verify"]);   
} else {
    //print mystery code.
    NSLog(@"%d",request.responseStatusCode);

}

}

Basically when you start the request using request startSynchronous it executes you server side code and returns a response string (or fails), you catch and handle the response string (or failure)in a delegate method you must implement from ASIHttpRequest -(void)requestFinished:(ASIHTTPRequest *)request. In the sample code I am parsing the response string into a JSON and then putting it into a dictionary for later use.

If you go through the tutorial this will all make sense to you very quickly. Hope it helps, good luck!