CGI support

[russsaidwords]

Would it be possible for you to implement a plugin for CGI as you have for e.g. Mojolicious or HTML::Mason? My problem is the numerous warnings thrown due to our legacy code's usage of the HTML generation functions in the CGI library. (I know, I know...) Mostly it's "Unable to find sub definition, declaration, constant definition or typeglob aliasing", as it seems that instead of directly exporting those functions, the CGI library generates them and then exports them in a non-typical way.

This would directly benefit my workflow and I'd be willing to donate money (USD) to the effort. If this is not possible at this time, is there a workaround for this that you can think of? A similar discussion may have been #2416 - however I don't quite follow the potential solution you presented there.

Thank you for all of your hard work!

[hurricup]

There are several way we could approach this. Could you please give me few samples of these dynamic methods (preferably from different packages, I'll take a look).

[russsaidwords]

If we take the instance of table cell generation, the CGI library provided HTML generation via the "td" subroutine.
My limited understanding is that these are the related CGI.pm lines for generating subroutines based on HTML tags:

sub _all_html_tags {
	return qw/
		a abbr acronym address applet Area
		b base basefont bdo big blink blockquote body br
		caption center cite code col colgroup
		dd del dfn div dl dt
		em embed
		fieldset font fontsize frame frameset
		h1 h2 h3 h4 h5 h6 head hr html
		i iframe ilayer img input ins
		kbd
		label layer legend li Link
		Map menu meta
		nextid nobr noframes noscript
		object ol option
		p Param pre
		Q
		samp script Select small span
		strike strong style Sub sup
		table tbody td tfoot th thead title Tr TR tt
		u ul
		var
	/
}

foreach my $tag ( _all_html_tags() ) {
	*$tag = sub { return _tag_func($tag,@_); };

	# start_html and end_html already exist as custom functions
	next if ($tag eq 'html');

	foreach my $start_end ( qw/ start end / ) {
		my $start_end_function = "${start_end}_${tag}";
		*$start_end_function = sub { return _tag_func($start_end_function,@_); };
	}
}

sub _tag_func {
    my $tagname = shift;
	my ($q,$a,@rest) = self_or_default(@_);

	my($attr) = '';

	if (ref($a) && ref($a) eq 'HASH') {
		my(@attr) = make_attributes($a,$q->{'escape'});
		$attr = " @attr" if @attr;
	} else {
		unshift @rest,$a if defined $a;
	}

	$tagname = lc( $tagname );

    if ($tagname=~/start_(\w+)/i) {
		return "<$1$attr>";
    } elsif ($tagname=~/end_(\w+)/i) {
		return "</$1>";
    } else {
	    return $XHTML ? "<$tagname$attr />" : "<$tagname$attr>" unless @rest;
	    my($tag,$untag) = ("<$tagname$attr>","</$tagname>");
	    my @result = map { "$tag$_$untag" } 
                              (ref($rest[0]) eq 'ARRAY') ? @{$rest[0]} : "@rest";
	    return "@result";
    }
}

We can then use td(...) to generate a table cell and it's content.

A "fuller" dive into what CGI.pm exports is located at line 227:

%EXPORT_TAGS = (
	':html2' => [ 'h1' .. 'h6', qw/
		p br hr ol ul li dl dt dd menu code var strong em
		tt u i b blockquote pre img a address cite samp dfn html head
		base body Link nextid title meta kbd start_html end_html
		input Select option comment charset escapeHTML
	/ ],
	':html3' => [ qw/
		div table caption th td TR Tr sup Sub strike applet Param nobr
		embed basefont style span layer ilayer font frameset frame script small big Area Map
	/ ],
	':html4' => [ qw/
		abbr acronym bdo col colgroup del fieldset iframe
		ins label legend noframes noscript object optgroup Q
		thead tbody tfoot
	/ ],
	':form'     => [ qw/
		textfield textarea filefield password_field hidden checkbox checkbox_group
		submit reset defaults radio_group popup_menu button autoEscape
		scrolling_list image_button start_form end_form
		start_multipart_form end_multipart_form isindex tmpFileName uploadInfo URL_ENCODED MULTIPART
	/ ],
	':cgi' => [ qw/
		param multi_param upload path_info path_translated request_uri url self_url script_name
		cookie Dump raw_cookie request_method query_string Accept user_agent remote_host content_type
		remote_addr referer server_name server_software server_port server_protocol virtual_port
		virtual_host remote_ident auth_type http append save_parameters restore_parameters param_fetch
		remote_user user_name header redirect import_names put Delete Delete_all url_param cgi_error env_query_string
	/ ],
	':netscape' => [qw/blink fontsize center/],
	':ssl'      => [qw/https/],
	':cgi-lib'  => [qw/ReadParse PrintHeader HtmlTop HtmlBot SplitParam Vars/],
	':push'     => [qw/multipart_init multipart_start multipart_end multipart_final/],

	# bulk export/import
	':html'     => [qw/:html2 :html3 :html4 :netscape/],
	':standard' => [qw/:html2 :html3 :html4 :form :cgi :ssl/],
	':all'      => [qw/:html2 :html3 :html4 :netscape :form :cgi :ssl :push/]
);

In many cases our various applications' code will use CGI qw/:all/;, bringing all exported tags into scope (through some Perl magic that I admittedly don't fully understand). This works and has for years, however, it leads to numerous warnings that the sub definition cannot be found, even with CGI.pm installed locally on the developer's machine and available via @INC or called out as part of an External Library in the IDE. This amounts to the IDE "crying wolf" leading to missed warnings of real importance.

Thanks for taking a look at this, and if anything I've said needs expanding or clarification please let me know. I would love to have this (and the subs!) "resolved".

[hurricup]

Thanks for the insights. Looking into it.
Btw, keep in mind: https://metacpan.org/pod/CGI#HTML-Generation-functions-should-no-longer-be-used

[russsaidwords]

That's always present on my mind... unfortunately I'm looking at two decades worth of technical debt that no one bothered to clean up before me, so now I'm stuck until the organization decides to perform a full rewrite.

[hurricup]

You may try artifacts from https://github.com/Camelcade/Perl5-IDEA/actions/runs/5630912445 should work just fine (see plugins) artifacts.
This version is for 2023.2 EAP.

[russsaidwords]

That is beautiful work! Thank you so much!

It appears that the definitions for items such as "popup_menu", "textfield", and "param" are correctly leading to their definitions in the CGI.pm file, but items such as "table", "th" or "td" which are proper HTML tags are not - which is not wholly unexpected, because they don't have definitions created in the same way as the others. The warnings regarding the subroutine resolution are cleared - and the warnings are also very usable, I actually fixed an error in the file I had been working on immediately because the warnings went from 83 down to 3, and 2 of them were related to a declaration of "@isa" as "our @isa" (I had never seen this before so this must be new, and I appreciate it!). I can definitely work with this!

This is awesome and I am ecstatic. I can't wait to see this update released through regular channels. Thank you again for all of your work!

[russsaidwords]

I see the "Support" button on the project home on GitHub, but it doesn't have any funding sources options listed. Can you add a FUNDING file in the project and/or let me know where and how I can get some money your way? This change is going to change everything for me and I would really like to pay you for your time. Thanks again.

[hurricup]

see #2534