how to assign hash element value to scalar?

[jugdish114]

sorry, here's a dumb simple question:

I am using the XML::Simple module to parse XML into a structure. This code works fine:

print "resultid:" . $response->{channel}->{result}->{resultid};

but assigning the value of the element has been difficult for me:

my $resultid = $response->{channel}->{result}->{resultid};

this does not work. I want to save the value of the has element as a scalar, or string, or whatever, for future use.

getting back into perl after a long absence. thanks in advance fer yer help.

fc thanks, here's some code examples for your reference:

#all this works:
my $xmlsimple = XML::Simple->new();
my $response = $xmlsiple->XMLin($xml_content->content);
print "resultid:" . $response->{channel}->{result}->{resultid};

#this doesn't work:
my $resultid = $response->{channel}->{result}->{resultid};
print "resultid: " . $resultid;

the output looks like this:

resultid:

but should look like this:

resultid: The item was added to the database.

thanks again!
fc
OK, here is much more code for your review, thanks:

  use XML::Simple;
  use LWP::Simple;
  use Data::Dumper;
  use HTTP::Request::Common;
  use LWP::UserAgent;

  my $url = "http://localhost/xml/add_order.xml";

  my $UserAgent = LWP::UserAgent->new(agent => 'perl post');

  my $xml_content = $UserAgent->request(POST $url,["userid" => $userid
+, 
                                                   "password" => $pass
+word,
                                                   "projectid" => $pro
+jectid,
                                                   "ordertypeid" => $o
+rdertypeid,
                                                   "orderdateid" => $o
+rderdateid,
                                                   "accountid" => $acc
+ountid,
                                                   "segcodeid" => $seg
+codeid,
                                                   "marketid" => $mark
+etid,
                                                   "marketday" => $mar
+ketday,
                                                   "marketmonth" => $m
+arketmonth,
                                                   "marketyear" => $ma
+rketyear,
                                                   "putcall" => $putca
+ll,
                                                   "strikeprice" => $s
+trikeprice,
                                                   "bs" => $bs,
                                                   "quantity" => $quan
+tity,
                                                   "orderprice" => $or
+derprice,
                                                   "entered_by" => $en
+tered_by
                                                   ]);

  print $xml_content->error_as_HTML unless $xml_content->is_success;

  #if we want to see the XML
  #printf $xml_content->content;
  #            also see ->code, ->is_info, ->is_success, ->is_error, -
+>header, ->message, etc

  my $xmlsimple = XML::Simple->new( );
  my $response = $xmlsimple->XMLin($xml_content->content);

  #if we wanted to see the object as a structure:
  #printf Dumper($response);

  if ($response->{channel}->{error}->{errorid} == "") {
    print "resultid: " . $response->{channel}->{result}->{resultid} . 
+"\n";
    print "resultdesc: " . $response->{channel}->{result}->{resultdesc
+} . "\n";
    print "orderid: " . $response->{channel}->{result}->{orderid} . "\
+n";

    my $resultid = $response->{channel}->{result}->{resultid};        
+#ERROR
    my $resultdesc = ${\$response->{channel}->{result}->{resultdesc}};
+    #ERROR
    my $orderid = $response->{channel}->{result}->{orderid};          
+#ERROR
    
    printf "ERROR resultid:" . $resultid . "\n";
    printf "ERROR: resultdesc:" . \$resultdesc . "\n";      
    printf "ERROR: orderid:" . $orderid . "\n\n";        
    
  #  foreach my $tmp (@{$response->{channel}->{result}}) {
  #    print "resultid: " . $tmp->{resultid} . "\n";
  #    print "resultdesc: " . $tmp->{resultdesc} . "\n";
  #    print "orderid: " . $tmp->{orderid} . "\n";
  #    print "\n";
  #  }
  } else {
    print "errorid: " . $response->{channel}->{error}->{errorid} . "\n
+";
    print "error desc: " . $response->{channel}->{error}->{errordesc} 
+. "\n";
    print "\n";  
  };

  my @ret_arry = ("test",
                  $resultid, 
                  $resultdesc, 
                  $orderid);
                  
  printf "ret_arry0:" . $ret_arry[0] . "\n";
  printf "ret_arry1:" . $ret_arry[1] . "\n";
  printf "ERROR ret_arry2:" . $ret_arry[2] . "\n";
  printf "ERROR ret_arry3:" . $ret_arry[3] . "\n\n";  
  
  #%ret_hash = (resultid => "a",
  #             resultdesc => "b");

  return @ret_arry;

Grandfather, et al:

Here's a link with a static XML file that is created for my code:
http://frank.mazzy.com/xfer/tmp.xml
And here is output from the command line:

Adding order
resultid: 0
resultdesc: Success - Order 109 has been added to ProjectID 4217.
orderid: 109
ERROR resultid:0
ERROR: resultdesc:SCALAR(0x181187c)
ERROR: orderid:109

ret_arry0:test
ret_arry1:
ERROR ret_arry2:
ERROR ret_arry3:

array: test   

arry0: test
arry1: 
ERROR arry2: 
ERROR arry3: 

done

thanks again!

Edited by planetscape - added code tags

[liverpole]

Hi jugdish114,

Can you post your exact code sample, please?

In the snippet you posted:

#all this works:
my $xmlsimple = XML::Simple->new();
my $response = $xmlsiple->XMLin($xml_content->content);
print "resultid:" . $response->{channel}->{result}->{resultid};

there's clearly a typo; in one place you have $xmlsimple, and another $xmlsiple.  I'm guessing maybe the part that "doesn't work" might be the reverse -- a typo which you've inadvertently corrected when you posted.

Try actually cutting and pasting your code (and be sure to use "code tags" (eg. <code> and </code>) around any code examples you submit).

One other suggestion -- put use strict; and use warnings; at the beginning of your program.  That may even solve your problem right away!

[jugdish114]

yes, those were simple errors when i was typing the code into the webform. the code runs, and does not use '$xmlsiple' anywhere.

so...

any ideas why i can't move the value of this hash element into a simple scalar? i'm guessing i have to do somehting like cast the hash as an array or string or something.

thanks.

[liverpole]

I can see a couple more issues.

One is that, when (as I mentioned) you use strict; and use warnings;, you get:

Global symbol "$userid" requires explicit package name at x line 17.
Global symbol "$password" requires explicit package name at x line 18.
Global symbol "$projectid" requires explicit package name at x line 19
+.
Global symbol "$ordertypeid" requires explicit package name at x line 
+20.
Global symbol "$orderdateid" requires explicit package name at x line 
+21.
Global symbol "$accountid" requires explicit package name at x line 22
+.
Global symbol "$segcodeid" requires explicit package name at x line 23
+.
Global symbol "$marketid" requires explicit package name at x line 24.
Global symbol "$marketday" requires explicit package name at x line 25
+.
Global symbol "$marketmonth" requires explicit package name at x line 
+26.
Global symbol "$marketyear" requires explicit package name at x line 2
+7.
Global symbol "$putcall" requires explicit package name at x line 28.
Global symbol "$strikeprice" requires explicit package name at x line 
+29.
Global symbol "$bs" requires explicit package name at x line 30.
Global symbol "$quantity" requires explicit package name at x line 31.
Global symbol "$orderprice" requires explicit package name at x line 3
+2.
Global symbol "$entered_by" requires explicit package name at x line 3
+4.
Global symbol "$resultid" requires explicit package name at x line 80.
Global symbol "$resultdesc" requires explicit package name at x line 8
+1.
Global symbol "$orderid" requires explicit package name at x line 82.

Of these, note that $resultid is defined within the if clause:

if ($response->{channel}->{error}->{errorid} == "") {
    # ...
    my $resultid = $response->{channel}->{result}->{resultid};\
    # ...
  };

... so of *course* it's not going to be available outside of the block.

You're also trying to return from outside of a subroutine, as well as comparing a string using "==" in the if statement I referenced above (you should really either use eq for string comparisons, or change "" to the numeric 0).

Is this the whole code sample, or just part of it?

And what happens when [id://jugdish114|you] add use strict; and use warnings; to it?

[jugdish114]

thanks, yes this is part of a subroutine, here's the beginning of it:

sub enter_order {

  my ($userid) = $_[0];
  my ($password) = $_[1];
  my ($projectid) = $_[2];
  my ($ordertypeid) = $_[3];
  my ($orderdateid) = $_[4];
  my ($accountid) = $_[5];
  my ($segcodeid) = $_[6];
  my ($marketid) = $_[7];
  my ($marketday) = $_[8];
  my ($marketmonth) = $_[9];
  my ($marketyear) = $_[10];
  my ($putcall) = $_[11];
  my ($strikeprice) = $_[12];
  my ($bs) = $_[13];
  my ($quantity) = $_[14];
  my ($orderprice) = $_[15];
  my ($entered_by) = $_[16];


yes, when i add 'use strict' it is not very pretty, some of the code outside the subroutine give errors.

and thanks for pointing out the error with the "==" rather than "eq" i think i write in too many languages to keep them straight.

see ya,

[liverpole]

    when i add 'use strict' it is not very pretty, some of the code outside the subroutine give errors.

You don't really believe that by not adding 'use strict' it means the errors magically go away, do you? :-)

[Hofmator]

Well, as an aside ... if you pass that many parameters to a subroutine, have you considered using a hash and using name => value pairs? That would greatly reduce the risk of errors and makes all these variable declarations unnecessary ...

I was thinking of something like the following ... suitably adjusted to your concrete requirements of course (are all parameters necessary, should they get a default value if not given, ...)

# call the sub
my_sub(userid => 'foo', password => 'bar');

sub my_sub {
  my %default_values = (userid => 'user', password => 'passwd');

  my %param = (%default_values, @_);

  print $param{userid}, $/;
  print $param{password}, $/;
  # ...
}

# or with all required arguments
sub my_sub {
  my @required = qw/userid password/;
  my %param = @_;

  for my $req (@required) {
    die "Subroutine my_sub called without required parameter: $req"
      unless exists $param{$req};
  }

  print $param{userid}, $/;
  print $param{password}, $/;
  # ...
}

[johngg]

It may be that you want to explicitly show which element of the subroutine's arguments is assigned to which variable but if not, you could save some typing by doing

my ($userid, $password, $projectid, ... , $entered_by) = @_;

I hope this is of use.

Cheers,

JohnGG

[GrandFather]

The update is good, but doesn't help :). Can you post the two variants along with just enough data to populate $xml_content->content and show the problem? Hint: use a __DATA__ section to provide the $xml_content->content content, or simple replace $xml_content->content with $str initialised to your sample XML (using a heredoc perhaps?).

By the way,

$response->{channel}->{result}->{resultid}

can be written

$response->{channel}{result}{resultid}

and you can interpolate directly into the string rather than using concatenation by

print "resultid: $resultid";

[j3]

Can you please provide us with a small sample of code that doesn't behave as you'd expect?