ALTer

Some quick notes…

I’m not doing very robust HTML parsing here, so if you don’t write your HTML like me then things probably won’t work. The code won’t handle uppercase tag or attribute names, spaces around the = signs, or attributes that aren’t double-quoted. It will work with attrbutes that are in odd orders, though.

If your image tag ends with an XHTML slash at the end, that slash will still be there after ALTer does its thing. If the tag doesn’t end in a slash, ALTer won’t add it.

That looks to be a handy script. You can make your regex handle uppercase tags by using the ‘i’ modifier (which makes the regex case insensitive). In the img regex, s+])?>+ would become s+])?>+i. (the period is a full stop and not part of the regex)

If you wanted to write some messy regex (is there any other kind :-) ), you could find unquoted attributes by looking for anything but spaces and single/double quote tags after the equals sign, ala m/src=([^”/s’]*)/ . I’m sure the regex I just gave fails in some instances. YMMV.

You’d want \s for a space character, not /s.

I’m aware of the i modifier, and you’d actually have to use it three times. Once after /alt\="/ once after m/src=”([^”]*)/ and once after +egs

Since the script was written primarily for my use, I’m not too concerned with different HTML styles. But if people want to suggest changes that will make things a bit more robust, please do. It could be handy.

I thought I would post this for you since I got so much milage from your Forms Errors Simplified article.

Just for info here’s how you could do it with HTML::TokeParser::Simple which will be more accepting about the nature of the HTML that’s put in.

— replace lines 45 - 65 in your script

use HTML::TokeParser::Simple; my $parser = HTML::TokeParser::Simple->new( $file ) || die “Can’t open $file for reading: $!”;

my $html; while (my $token = $parser->get_token) {

  # find image files without alt 
  if ( $token->is_start_tag('img') ) {
      my $tag        = $token->return_tag;
      my $attr       = $token->return_attr;

      # If we have an alt entry already we'll skip it

      if ( defined $attr->{alt} ){

    # we could change the above test to look in %texts for new alt contents
    # for tags that exist but are empty
    # if ( defined $attr->{alt} and $attr->{alt} ne '' )

    next;
  }
  # Add an alt attribute
  my $alt = exists $texts{ $attr->{src} } ? $texts{ $attr->{src} } : '';
  $token->set_attr( alt => $alt );

  }
  $html .= $token->as_is;

} open (OUT, “>$file”); print OUT $html;

— above code is mostly untested unless otherwise stated

Also here’s a link to an example of a script I wrote to extract inline css to external style sheets.

Extract inline styles to an external style sheet http://www.perlmonks.org/index.pl?node_id=292225

Clayton

PS the code would look nicer if the comment system would let me put code tags around it. :)

That’s a good idea. I hadn’t thought about using an actual HTML parser. I wonder how fast this method would be though. One advantage of the big ugly regex is that the script takes under a second to process 150 3kb HTML files.

On the other hand, since this is a utility script that is rarely run, speed probably isn’t much of an issue as long as it doesn’t take more than a few minutes to process.

Since it’s a rarely used utility script I’m more worried about maintainability and robustness than speed.

I’d use a set of similar scripts for all kinds of HTML transformations when refactoring a new customers old website.

It would be nice to set up a find and replace script for this in BBEdit using grep. I would if I knew how.

Looking for a regex to find and tags that have file:/// in them… any ideas?

use

while ( my $line = ) {}

instead of

@lines = ;

for those really big files, you will save a lot of memory this way.

thx for the script

What a “perler” of an idea (sorry about that) but seriously this is very clever. As a bit of a novice I use dreamweaver to do all my design work and use the find & replace all the time to try and save work, it would be nice to just whip up a script sometimes!