CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway.

msinfo has asked for the wisdom of the Perl Monks concerning the following question:

hi monks,

i am getting below message in my web pages, which use CGI::Ajax module

No head/html tags, nowhere to insert. Returning javascript anyway

Here is skeleton of my code:

my $pjx = new CGI::Ajax( 'exported_func' => \&perl_func);
print $pjx->build_html($cgi, \&Show_Html);

sub perl_func
{
# ajax function
}

sub Show_Html
{
# html generating code
    # first check session info
    print $session->header();
    # generate html 
print $cgi->start_html();
# remaining html code
print $cgi->end_html();
}
[download]

Now this generates, html properly and even calls Ajax function, but displays above warning message in browser, all the time.

I went through CGI::Ajax documentation, and below are the lines, which I doubt are related to problem. Arguments: The CGI object, and either a coderef, or a string containing html. Optionally, you can send in a third parameter containing information that will get passed directly to the CGI object header() call.

or is it mandatory to write Show_Html as follows only

sub Show_HTML {
    my $html = <<EOT;
  <HTML>
# html generating code
  </HTML>
EOT
    return $html;
  }
[download]

While doing debugging with Firefox, I found out that actual response body was as follows

# html generated by Show_Html
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-U
+S">
<head>
<title></title>
</html>

# and again html generated by cgi::ajax
<html>
</html>
[download]

Comment on CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. Select or Download Code

Replies are listed 'Best First'.
Re: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by poj (Abbot) on Sep 01, 2013 at 16:03 UTC
The `Show_HTML` sub should return the html, not print it. It is not mandatory to use a here-doc, you could built it up like this ; `sub Show_HTML { my $html = $cgi->start_html(); $html .= $cgi->p('Enter something'); $html .= $cgi->input( {-type=>'text', -name=>"va1",-id=>"val1", onkeyup=>"exported_func( ['val1'], ['resultdiv'] );"} ); $html .= $cgi->br; $html .= $cgi->div( {-id=>"resultdiv"} ); $html .= $cgi->end_html(); return $html; }` [download] poj	[reply] [d/l] [select]
Re^2: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by msinfo (Sexton) on Sep 01, 2013 at 17:53 UTC
Thanks poj The Show_HTML sub should return the html, not print it I learned that from you. The error message goes away, when I use code format shown by you. But, when conditional statement is inserted, in between, it fails. Error says - problem at if condition. When I remove if condition, all goes well. `my $html = $session->header(); $html .= $cgi->start_html(-charset=>'UTF-8',-style => {'src' => 'sty +lesheet/style.css'}); $html .= $cgi->div({-id=>'container'}, $cgi->img({src=>'images/pic.png', height=>'100px', + width=>'150px'}), if ($cgi->p(($session->is_expired) \|\| ($session->i +s_empty)) =1) { $cgi->p("logged") }, $cgi->div(` [download]	[reply] [d/l]
Re^3: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by Anonymous Monk on Sep 01, 2013 at 18:26 UTC
Doctor Doctor it hurts when I do this, but it doesn't hurt when I don't do it Ok then :)	[reply]
Re^4: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by msinfo (Sexton) on Sep 01, 2013 at 18:38 UTC
Re^5: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. (mini-if ternary) by Anonymous Monk on Sep 01, 2013 at 19:13 UTC
Some notes below your chosen depth have not been shown here
Re^3: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by poj (Abbot) on Sep 01, 2013 at 19:34 UTC
Put the conditional outside the div ; `my $msg = ($session->is_expired \|\| $session->is_empty) ? 'logged':''; $html .= $cgi->div({-id=>'container'}, $cgi->img({src=>'images/pic.png', height=>'100px',width=>'150px'}), $cgi->p($msg),$cgi->div(` [download] poj	[reply] [d/l]
Re^4: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by msinfo (Sexton) on Sep 01, 2013 at 21:32 UTC
Re^5: CGI::Ajax No head/html tags, nowhere to insert. Returning javascript anyway. by Anonymous Monk on Sep 02, 2013 at 00:01 UTC
Some notes below your chosen depth have not been shown here


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