I am glad it did. Happy Coding !

You can put it in GitHub repository and share the link with me. Dropbox will also work.

Can I include it as an attachment somehow? Share it via dropbox or something?

Thanks.

Hi Steve,

Apologies for the delay.

It would help if you had kept the code in a notepad or something. Nevertheless I used the exact same code that you have pasted and tried with v9.33 and it seems to be working fine. Please find the screenshot below:

Can you give the entire source code so that I can try that ?

Thanks,
RC

[2023-08-04 22:51:45.24467] [3372701] [trace] [quBKk0KzFuuL] POST “/login”
[2023-08-04 22:51:45.24542] [3372701] [trace] [quBKk0KzFuuL] Routing to controller “myWebSite::Controller::CustomController” and action “validUserCheck”
[2023-08-04 22:51:45.24637] [3372701] [trace] [quBKk0KzFuuL] Rendering template “myTemplates/homepage.html.ep”
[2023-08-04 22:51:45.24813] [3372701] [trace] [quBKk0KzFuuL] Rendering cached template “layouts/master.html.ep”
[2023-08-04 22:51:45.24895] [3372701] [trace] [quBKk0KzFuuL] 200 OK (0.00429s, 233.100/s)
[2023-08-04 22:51:45.24986] [3372701] [error] [quBKk0KzFuuL] Can’t use an undefined value as an ARRAY reference at /usr/local/share/perl5/5.32/Mojolicious/Controller.pm line 231.

[2023-08-04 22:51:45.25005] [3372701] [trace] [quBKk0KzFuuL] Template “exception.development.html.ep” not found
[2023-08-04 22:51:45.25018] [3372701] [trace] [quBKk0KzFuuL] Template “exception.html.ep” not found
[2023-08-04 22:51:45.25027] [3372701] [trace] [quBKk0KzFuuL] Rendering cached template “mojo/debug.html.ep”
Mojo::Reactor::Poll: I/O watcher failed: A response has already been rendered at /usr/local/share/perl5/5.32/Mojolicious/Controller.pm line 154.

mojo version
CORE
Perl (v5.32.1, linux)
Mojolicious (9.33, Waffle)

Here’s the code in my CustomController.pm. Do you need to see anything else?

package myWebSite::Controller::CustomController;
use Mojo::Base ‘Mojolicious::Controller’, -signatures;

# This action will render a template
sub welcome ($self) {

# Render template “example/welcome.html.ep” with message
# $self->render(msg => ‘Welcome to the Mojolicious real-time web framework!’);
$self->render(template => ‘myTemplates/homepage’,
msg => ‘Welcome to my personal web site.’);
}

# Display the login page
sub displayLogin {

my $self = shift;

# if(alreadyLoggedIn($self))
# see comments in https://thecurioustechnoid.com/mojolicious-part-3-session-management/
# evidently, you can no longer render 2 things in one route. alreadyLoggedIn renders myTemplates/login
# if someone is not logged in, then this code also renders myTemplates/login if someone is not logged in.
# if we just check for the session here, we avoid the second render.
if($self->session(‘is_auth’))
{
# user already logged in. Senf the to the welcome page
welcome($self);
}
else
{
# user not logged in. Send them to login page
$self->render(template=> “myTemplates/login”, error_message=> “”);
}
}

sub validUserCheck {

my $self = shift;

# test/demo data
my %validUsers = (“JANE” => “welcome123″
,”JILL” => “welcome234″
,”TOM” => “welcome345″
,”RAJ” => “test123″
,”RAM” => “digitalocean123”
);

my $user = uc($self->param(‘username’));
my $password = $self->param(‘pass’);

if(exists($validUsers{$user}))
{
if($validUsers{$user} eq $password)
{
# create a session cookie
$self->session(is_auth => 1);
# store the username in the cookie
$self->session(username => $user);
# cookie expires in 10 minutes if no activity (how is this detected?)
$self->session(expiration => 600);

# direct the user to the home page
welcome($self);
}
else
{
# wrong password
$self->render(template=> “myTemplates/login”, error_message=> “Invalid password. Try again.”);
}
}
else
{
# user not found
$self->render(template=> “myTemplates/login”, error_message=> “User $user not found in this system.”);
}
}

# check if user is already logged in
sub alreadyLoggedIn {

my $self = shift;

return 1 if $self->session(‘is_auth’);

# user not logged in. Send them to login page
$self->render(template=> “myTemplates/login”, error_message=> “You must log in to use this web site”);

return 0;
}

# log out
sub logout {

my $self = shift;

# end the session by expiring the cookie in 1 second?
$self->session(expires => 1);
$self->render(template=> “myTemplates/logout”);

}

sub loadTestimonials{

my $self = shift;
my $all_testimonials_html;

foreach my $all_testimonials (@{$self->dbhandle->fetch_all_testimonials})
{
$all_testimonials_html .= ”

“.$all_testimonials->{testimonial}.”
“.$all_testimonials->{published_by}.””.$all_testimonials->{published_on}.”

“;
}
$self->render(template => ‘myTemplates/managetestimonials’,msg => ‘View Testimonials’,alltestimonials => $all_testimonials_html);

}

sub saveTestimonial{

my $self = shift;
my $new_testimonial = $self->param(‘userReview’);
my $user = $self->session(‘username’);

$self->dbhandle->publish_testimonial($new_testimonial,$user);
&loadTestimonials($self);
}

1;

But now the I/O watcher error seems to have disappeared. Are you using Mojolicious v9.22 or higher version ?

Share your code please, I will have a look.

So, when I successfully log in, I see this from morbo:

[2023-08-03 17:50:32.45835] [3241784] [trace] [eR8itINlVUpS] POST “/login”
[2023-08-03 17:50:32.45887] [3241784] [trace] [eR8itINlVUpS] Routing to controller “myWebSite::Controller::CustomController” and action “validUserCheck”
[2023-08-03 17:50:32.45972] [3241784] [trace] [eR8itINlVUpS] Rendering cached template “myTemplates/homepage.html.ep”
[2023-08-03 17:50:32.46007] [3241784] [trace] [eR8itINlVUpS] Rendering cached template “layouts/master.html.ep”
[2023-08-03 17:50:32.46183] [3241784] [trace] [eR8itINlVUpS] 200 OK (0.003493s, 286.287/s)
[2023-08-03 17:50:32.46265] [3241784] [error] [eR8itINlVUpS] Can’t use an undefined value as an ARRAY reference at /usr/local/share/perl5/5.32/Mojolicious/Controller.pm line 231.

That line is inside a subroutine called signed_cookie.

my $sum = Digest::SHA::hmac_sha256_hex(“$name=$value”, $self->app->secrets->[0]);

So it looks like it was going to render homepage.html.ep then this error happened.

Thanks. I had already made the change Peter suggested while I was doing part 3. This error started as was doing part 4.

Hi Steve,

This looks like the same issue as I mentioned here:

https://thecurioustechnoid.com/mojolicious-part-3-session-management/#comment-307

Mojolicious version issue. You might have to tweak the code a little to make it work with latest version or get the same version of Mojolicious that I used, v9.22 for this code to work.

Hope it helps !

Thank you for your kind words.

I moved to Django for a while and lately tinkering with VueJS + FastAPI. Been sometime since I used Mojolicious. I will try to see if I can create an article for this. If you are already working on it and are stuck somewhere, happy to weigh in.

[2023-08-02 23:16:22.26368] [3241784] [error] [gloA8P2znTQh] Can’t use an undefined value as an ARRAY reference at /usr/local/share/perl5/5.32/Mojolicious/Controller.pm line 231.
[2023-08-02 23:16:22.26386] [3241784] [trace] [gloA8P2znTQh] Template “exception.development.html.ep” not found
[2023-08-02 23:16:22.26399] [3241784] [trace] [gloA8P2znTQh] Template “exception.html.ep” not found
[2023-08-02 23:16:22.26407] [3241784] [trace] [gloA8P2znTQh] Rendering cached template “mojo/debug.html.ep”
Mojo::Reactor::Poll: I/O watcher failed: A response has already been rendered at /usr/local/share/perl5/5.32/Mojolicious/Controller.pm line 154.

I didn’t touch any of the login code.

flush privileges;

as root before demo can log into mysql.

Hello, publications are stored in the database, but in the example you suggested, user accounts are stored in CustomController.pm

sub validUserCheck {

my $self = shift;

# List of registered users
my %validUsers = ( “JANE” => “welcome123″
,”JILL” => “welcome234″
,”TOM” => “welcome345″
,”RAJ” => “test123″
,”RAM” => “digitalocean123”
);

it would be very interested to implement the registration page and have the credentials stored in the data base…

Actually, thank you very much for this article, it’s the only good article besides the official documentation that I could find where I could get information about Mojolicious.

The idea of these posts were to give you an idea as to how to work in Mojolicious. Are you stuck somewhere ? I can help if so.

Hi Peter,

Thank you for taking the time to go through the article. I have changed the code so that others don’t face the same issue.

Happy Coding.

Cheers,
RC

Had error: A response has already been rendered at /home/mojo/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0/Mojolicious/Controller.pm line 154.
# trace] [xx5kwL28OTom] Rendering cached template “mojo/debug.html.ep”
Mojo::Reactor::Poll: I/O watcher failed: A response has already been rendered at /home/mojo/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0/Mojolicious/Controller.pm line 154.

As the previous response changing this line make it works:
## if(&alreadyLoggedIn($self)){
if($self->session(‘is_auth’)){

Hope it save somebody frustration and enjoy your tutorial.
So far is fantastic, easy to understand.

Thanks for your kind words.

1. This article was written with english websites in mind, but good point.
2. You mean assign the value from the hash to a variable for clarity ? Well these articles are written with an intention to get you started with Mojolicious with ease. I guess after that, you would be writing better web apps than what is in this article 🙂

Cheers.

Hi Paul,

I looked at your code and found the cause for the issue you are facing. In the latest version of Mojolicious, it forbids you from rendering more than once which was not the case in past. You can check the change log here in the below link. Check version 9.25 comments.

https://metacpan.org/dist/Mojolicious/changes

I tried your code using my old mojolicious docker which has version 9.22 and your code worked like a charm. In case you want to use my docker you can check it here: https://hub.docker.com/r/curioustechnoid/mojolicious

What you can do with the latest Mojolicious is that, use alreadyLoginIn subroutine to render or redirect based on login validation, and don’t render after this subroutine call. That should solve your problem.

Hope this helps.

Cheers!

Of course, thank you ! I put it here:

https://github.com/Paul-sinbud2004/Mojolicious_notes/blob/main/xpsweb/lib/xpsweb/Controller/Xpscontroller.pm

The main issue is in line 23 of this file.

Surprising. The same code that is developed in these articles can be found in GitHub – https://github.com/curioustechnoid/IntroductionToMojolicious
Can you share your code with me, may be I can have a look ?

Thanks for your replying.
The alreadyLoggedIn function is really useful in terms of reuse. And it works well in the “under” statement.
But I tried many times, when calling alreadyLoggedIn in sub function displayLogin, the “get /” failed, warns:

Mojo::Reactor::Poll: I/O watcher failed: A response has already been rendered at /home/paul/perl5/lib/perl5/Mojolicious/Controller.pm line 154.

So I have to rewrite it like before to make it work. I guess it is caused by the next statement after “return 1”.

Hi Paul,

Thank you for visiting the site. The reason for using the function alreadyLoggedIn is re-usability. The function is already used in the “under” to restrict access to certain parts of the website like testimonials. Keeping this logic in subroutine which can be used in multiple places helps when we want to change the logic in future. In such an event, you just have to change this subroutine and it starts working everywhere.

Cheers!