Retaining the value of a variable in Perl

Question

I've a GUI front-end (HTML and JavaScript) a Perl back-end. On clicking a certain button on the home page of the front-end, the Perl back-end receives a specific argument. So this argument leads to change of value of a variable ( $checkInfo ) which is then given back to the GUI. The GUI now pops up a message which displays $checkInfo and on closing the pop-up, another page (say page 2) opens. On page 2 is a certain button which emails $checkInfo to a certain email address.

The problem I'm facing is that $checkInfo is equal to "" on page 2. On page 1, the back-end returns $checkInfo = something to the GUI but that value is lost when I go to page 2. I've tried declaring $value as state $checkInfo but that doesn't work either. I use $checkInfo only in the main() function.

In the code, all you need to know is that preSubmitCheck::autoSubmitCheck return the value such that $checkInfo->{rc} != 0 and in the first iteration $mode ne 'ticket' but $mode eq 'ticket' in the second iteration. In the second iteration, I need the value of $checkInfo to be the same as the first iteration value.

Perl code:

my $username = defined param("username") ? param("username") : undef;
my $action = defined param("run_type") ? param("run_type") : undef;
my $cit_suite = defined param("cit_suite") ? param("cit_suite") : undef;
my $buildroot = defined param("buildroot") ? param("buildroot") : undef;
my $site = defined param("site") ? lc(param("site")) : undef;
my $branch = defined param("branch") ? param("branch") : undef;
my $hw = defined param("hw") ? param("hw") : undef;
my $variant = defined param("variant") ? param("variant") : undef;
my $num_runs = defined param("num_runs") ? param("num_runs") : undef;
my $justification = defined param("justification") ? param("justification") : undef;
my $mode = defined param("userAction") ? param("userAction") : undef;
my $jobID = defined param("jobID") ? param("jobID") : undef;
my $cancel_type = defined param("canceltype") ? param("canceltype") : undef;

    state $checkInfo;
    my $error;
    my %rtn = (
           rc => 0,
           message => "All is well."
           );

    if($mode ne "ticket") {
        $checkInfo = preSubmitCheck::autoSubmitCheck($site,$username,$num_runs);
    }
    if(defined $checkInfo && $checkInfo->{rc} == 0){
        my $target = 1;
    }
    else {
        if($mode eq "ticket"){
            $error = $checkInfo->{message};
            my $rtnFromTicket = sendTicket(
                username => $username,
                cit_suite => $cit_suite,
                action => $action,
                buildroot => $buildroot,
                site => $site,
                branch => $branch,
                hw => $hw,
                variant => $variant,
                num_runs => $original_num_runs,
                justification => $justification,
                errorMessage => $error
               );
            $rtn{rc} = 2;
            $allMessage .= " Your job couldn't be automatically submitted: ". $error;
            $allMessage .= " Email info: ". $rtnFromTicket -> {message};
            $rtn{message} = $allMessage;
            print "00delimiter00";       # use as a delimiter to split from useless print information, and make the front end got the json data.
            print to_json(\%rtn);
            exit $rtn{rc};
        }
        else{
            $error = $checkInfo->{message};
            $rtn{rc} = $checkInfo->{rc};
            if($rtn{rc} == 6) {
                $allMessage .= " Your job couldn't be automatically submitted: ". $error. " You can schedule your run or open a ticket with the SMOKES team.";
            }
            else {
                $allMessage .= " Your job couldn't be automatically submitted: ". $error;
            }
            $rtn{message} = $allMessage;
            print "00delimiter00";       # use as a delimiter to split from useless print information, and make the front end got the json data.
            print to_json(\%rtn);
            exit $rtn{rc};
        }
     }

GUI code:

var query = "username=<% $ARGS{username} %>";
if(Mode=="all"){
    query += "&run_type=Presub_smoke";
} 
else {
    query += "&run_type=CIT" + "&cit_suite=" + document.getElementById("citsuite").value;
}
query += "&buildroot=" + encodeURIComponent(document.getElementById("buildroot").value);
query += "&site=" + encodeURIComponent(document.getElementById("remoteSite").value);
query += "&branch=" + encodeURIComponent(document.getElementById("branch").value);
query += "&hw=" + encodeURIComponent(document.getElementById("hwtype").value);
query += "&variant=" + encodeURIComponent(document.getElementById("variant").value);
query += "&num_runs=" + document.getElementById("num_runs").value;
query += "&justification=" + encodeURIComponent(document.getElementById("justification").value);
query += "&userAction=" + encodeURIComponent(action);
var submitFcts = new Array();
submitFcts[3] = "updateSubmitInfo";
submitFcts[4] = "return_request";
makeUserRequest2("<% $CGI_form_path %>", query, submitFcts, "");

I hope this suffices for answering my question. Thanks!

Answer 1

state only preserves the value of a variable within a single process. When running as CGI, there's a new process for each HTTP request.

If you want to store state across requests, you will need to persist it somewhere that survives across requests -- for instance, by storing it in a cookie, in a session, or in a database.