iOS custom segue help...

[shahab47]

Hello there.

I am very new to apple/mac.
I am designing a simple app, where I check the username and password and if that matches, it would open a new page. It is probably very simple. Its just that I am new to this. So I don't know.

Everything works fine except that I cannot put a condition in the custom segue which checks if username and password are correct or not, before loading the next page.

How can I do that?

This is my custom segue: (I need to add a condition where I can check if username and password in the source view controller are correct or not before loading destination view controller.

I am attaching my entire project in zip file. Here.

Thanks
Shahab

#import "Akire_login_customsegue.h"

@implementation Akire_login_customsegue
-(void)perform
{
    [self.sourceViewController presentModalViewController:self.destinationViewController animated:YES];
}
@end

 

[Sykte]

Hello there.

I am very new to apple/mac.
I am designing a simple app, where I check the username and password and if that matches, it would open a new page. It is probably very simple. Its just that I am new to this. So I don't know.

Everything works fine except that I cannot put a condition in the custom segue which checks if username and password are correct or not, before loading the next page.

How can I do that?

This is my custom segue: (I need to add a condition where I can check if username and password in the source view controller are correct or not before loading destination view controller.

I am attaching my entire project in zip file. Here.

Thanks
Shahab

#import "Akire_login_customsegue.h"

@implementation Akire_login_customsegue
-(void)perform
{
    [self.sourceViewController presentModalViewController:self.destinationViewController animated:YES];
}
@end

I honestly do not think a segue is a proper location to verify credentials. I would run a conditional check in the source viewcontroller then only push the segue if the credentials pass.

However to answer your question you can access the source and destination properties via self.sourceViewController & self.destinationViewController.

Hope this helps.

 

[shahab47]

Hello Skyte.

Thanks a lot for your answer.

I think I am doing the credential check in the source view controller only. Once the credential match, I print out a label saying"login successful" or "login failed". And I can do that successfully.

Now after this text label is displayed, I want the screen to show up 2nd view controller. For this, I don't know any other way. I don't want to use "nav bar"

so once I click the "submit" button, this action checks the credentials:

- (IBAction)alogin:(id)sender {
    
    //Store the TF text into Button var declared in .h file
    self.B_login = self.TF_username.text;
    NSString *uname_var = self.B_login;
    //Store the TF text into Button var declared in .h file
    self.B_login = self.TF_password.text;
    NSString *pword_var = self.B_login;    
    //We cannot use this above variable anywhere by itself.
    //So we assign this to another variable.
    
    //Initialize something. need to explain later
    NSString *result_pass_var = [[NSString alloc] initWithFormat:@"Login Success"];
    NSString *result_fail_var = [[NSString alloc] initWithFormat:@"Login Failed!"];
    NSString *username_input = [[NSString alloc] initWithFormat:@"shahab"]; 
    NSString *password_input = [[NSString alloc] initWithFormat:@"inamdar"];
    
    
    NSString *result_var = [[NSString alloc] initWithFormat:@"%@ %@", uname_var,pword_var];
    self.LB_result.text = result_var;
    
    if ([uname_var isEqualToString:username_input] && [pword_var isEqualToString:password_input])   
        self.LB_result.text = result_pass_var;
    else 
        self.LB_result.text = result_fail_var;
}

Now I tried to access "self.sourceviewcontroller.LB_result.text == bla bla" in my custom segue, but it gives error. (LB_result doesn't show up when I hit the dot after self.sourceviewcontroller).

So in above code, I checked the credential. Now I should push the screen to destination controller. Could you please suggest, how do I do that? What code should I add above so that destination view controller opens up?

I am very new to this. ANy help would be appreciated.
Thanks
Shahab

 

[Sykte]

Hi Shahab47,

You should do some reading on how to cast objects. However, I have posted two examples below on how to accomplish your goal.

myViewControllerName *loginViewController = (myViewControllerName *) self.sourceViewController


 //Now you can access your property.
loginViewController.LB_result.text

or

//You may cast an object and access your property all within one line of code
//I have to say I typically prefer the option above.
((myViewControllerName *)self.sourceViewController).LB_result.text

Hope this helps. I'm heading out shortly but I will try and give you an example on how to handle everything in your source(login)ViewController when I get back.

Good Luck.

 

[shahab47]

Hello Skyte.

Your suggestion worked.
I can now log in. And the credential check is done in the custom segue though.
Thank you so much.

I remember you told me that its not a good idea to check credentials in custom segue.
So I did a little research and decided to do the credential check in UIViewcontroller file only.

So I created a new UIVIewController Object and named it as loginafter_viewcontroller.m. Now when I check credentials in original UIVIewcontroller then if credentials check out, I need to call this loginafter_viewcontroller.

And I couldn't do that. It opens a black page instead of my "loginafter_viewcontroller". the project doesn't crash but its black screen.

Here is my code:

if username and password equal to bla and bla, open "loginafter_veiwcontroller.
    
    if ([uname_var isEqualToString:username_input] && [pword_var isEqualToString:password_input]) 
    {

        loginafter_ViewController *myNewVC = [[loginafter_ViewController alloc] init];        
        [self presentModalViewController:myNewVC animated:YES];

If you find some time, please explain to me how to do that. I think I am again missing a statement above.
Thanks again a lot
Shahab

 

[dejo]

Shabab, please see this Sticky note: Posting code, please use the

 tags[/URL]