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CL-WHO-like HTML templating for other languages?

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别那么骄傲
别那么骄傲 2020-12-10 04:44

Common Lisp guys have their CL-WHO, which makes HTML templating integrated with the \"main\" language thus making the task easier. For those who don\'t know CL-WHO, it looks

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  • 余生分开走
    2020-12-10 05:12

    Perl's standard CGI module can do something similar:

    #!/usr/bin/perl

use strict;
use warnings;
use CGI qw/:standard/;

print 
    start_html("An example"),
    h1(
        {
            -align => "left",
            -class => "headerinfo",
        },
        'this is an example'
    ),
    "The CGI module has functions that add HTML:",
    ul( map li($_),
        ("start_html",
        "h1, h2, h3, etc.",
        "ol, ul, li",
        "ol, ul, li",
        "table, tr, th, td")
    ),
    "and many more.",
    end_html();

    That produces:

    <!DOCTYPE html
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>An example</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h1 class="headerinfo" align="left">this is an example</h1>The CGI module has functions that add HTML:<ul><li>start_html</li> <li>h1, h2, h3, etc.</li> <li>ol, ul, li</li> <li>ol, ul, li</li> <li>table, tr, th, td</li></ul>and many more.
</body>
</html>

    The li section could be rewritten like this

    print ol(map li($_), @list);

    if you had a list or an array.

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  • 伪装坚强ぢ
    2020-12-10 05:16

    Perl's CGI module has support for something like this.

    use CGI ':standard';
use Lisp::Fmt 

print header();

print table( { -border => 1, -cellpading => 4},
    loop({ below => 25, by=> 5}, sub {
        my $i = shift;
        tr( {-align => 'right'} ,
            loop({ from => $i, below $i + 5}, sub {
                my $j = shift;
                td({-bgcolor => ($oddp eq $j ? 'pink' : 'green')}
                    fmt("~@R", 1+$j);
            })
        )
    });

    I tried to keep it lispy, so you'll have to implement a lispy loop function yourself. I don't really program Common List, so I hope I understood your code correctly.

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  • 谎友^
    2020-12-10 05:20

    Clojure

    There are a bunch of CL-WHO-inspired HTML-generating libraries available in Clojure (as one would expect, Clojure being a Lisp). Here's how you could do it using the HTML library that comes with Compojure, and cl-format:

    (use 'compojure.html
     'com.infolace.format)

(html
 [:table {:border 0 :cellpadding 4}
  (map (fn [tds] [:tr {:align "right"} tds])
       (partition 5 (map (fn [num color]
                           [:td {:bgcolor color}
                            (cl-format nil "~@R" (inc num))])
                         (range 25)
                         (cycle ["green" "pink"]))))])

    Compojure's HTML library makes good use of Clojure's literal hash-maps as attribute/value pairs, and using literal vectors for tags instead of lists for everything helps the tags stand out a bit and avoids some of the need for macro magic.

    partition breaks up a collection into groups of some number of elements. cycle generates an infinitely repeating list of the elements of a collection. These plus range and map help you avoid explicit loops and counter variables.

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  • 太阳男子
    2020-12-10 05:20

    There's html-tags, a Chicken Scheme extension. html-tags generates either [X]HTML or SXML.

    Here's an example (using the loop extension and considering string output):

    (<table> border: 0 cellpadding: 4
  (string-intersperse
   (loop for i below 25 by 5
         collect
         (<tr> align: "right"
               (string-intersperse
                (loop for j from i below (+ i 5)
                      collect
                      (<td> bgcolor: (if (odd? j)
                                         "pink"
                                         "green")
                            (+ 1 j))))))))

    I'd add links to the loop and html-utils extensions (which is built on top of html-tags), but stackoverflow is considering I'm a spammer and only allows me to post a maximum of two links.

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  • 情歌与酒
    2020-12-10 05:26

    For CPAN offerings have a look at the following (in alphabetical order)...

    • Builder
    • HTML::AsSubs
    • HTML::Tiny
    • Markapl
    • Template::Declare
    • XML::Generator

    Using the table part of the CL-WHO example provided (minus Roman numerals and s/background-color/color/ to squeeze code into screen width here!)....


    Builder

    use Builder;
my $builder = Builder->new;
my $h = $builder->block( 'Builder::XML' );

$h->table( { border => 0, cellpadding => 4 }, sub {
   for ( my $i = 1; $i < 25; $i += 5 ) {
       $h->tr( { align => 'right' }, sub {
           for my $j (0..4) {
               $h->td( { color => $j % 2 ? 'pink' : 'green' }, $i + $j );
           }
       });
   } 
});

say $builder->render;


    HTML::AsSubs

    use HTML::AsSubs;

my $td = sub {
    my $i = shift;
    return map { 
        td( { color => $_ % 2 ? 'pink' : 'green' }, $i + $_ )
    } 0..4;
};

say table( { border => 0, cellpadding => 4 },
    map { 
        &tr( { align => 'right' }, $td->( $_ ) ) 
    } loop( below => 25, by => 5 )
)->as_HTML;


    HTML::Tiny

    use HTML::Tiny;
my $h = HTML::Tiny->new;

my $td = sub {
    my $i = shift;
    return map { 
        $h->td( { 'color' => $_ % 2 ? 'pink' : 'green' }, $i + $_ )
    } 0..4;
};

say $h->table(
    { border => 0, cellpadding => 4 },
    [
        map { 
            $h->tr( { align => 'right' }, [ $td->( $_ ) ] )  
        } loop( below => 25, by => 5 )    
    ]
);


    Markapl

    use Markapl;

template 'MyTable' => sub {
    table ( border => 0, cellpadding => 4 ) {
       for ( my $i = 1; $i < 25; $i += 5 ) {
           row ( align => 'right' ) {
               for my $j ( 0.. 4 ) {
                   td ( color => $j % 2 ? 'pink' : 'green' ) { $i + $j }
               }
           }
       } 
    }
};

print main->render( 'MyTable' );


    Template::Declare

    package MyTemplates;
use Template::Declare::Tags;
use base 'Template::Declare';

template 'MyTable' => sub {
    table {
        attr { border => 0, cellpadding => 4 };
        for ( my $i = 1; $i < 25; $i += 5 ) {
            row  {
                attr { align => 'right' };
                    for my $j ( 0..4 ) {
                        cell {
                            attr { color => $j % 2 ? 'pink' : 'green' } 
                            outs $i + $j;
                        }
                    }
            }
        } 
    }
};

package main;
use Template::Declare;
Template::Declare->init( roots => ['MyTemplates'] );
print Template::Declare->show( 'MyTable' );


    XML::Generator

    use XML::Generator;
my $x = XML::Generator->new( pretty => 2 );

my $td = sub {
    my $i = shift;
    return map { 
        $x->td( { 'color' => $_ % 2 ? 'pink' : 'green' }, $i + $_ )
    } 0..4;
};

say $x->table(
    { border => 0, cellpadding => 4 },
    map { 
        $x->tr( { align => 'right' }, $td->( $_ ) )  
    } loop( below => 25, by => 5 )    
);


    And the following can be used to produce the "loop" in HTML::AsSubs / HTML::Tiny / XML::Generator examples....

    sub loop {
    my ( %p ) = @_;
    my @list;

    for ( my $i = $p{start} || 1; $i < $p{below}; $i += $p{by} ) {
        push @list, $i;
    }

    return @list;
}
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  • 抹茶落季
    2020-12-10 05:29

    Haskell

    Haskell has an HTML combinator library that is not all that different from CL-WHO. The lazy functional approach to programming, though, does result in a much different idiomatic iteration structure than the loop facilities in Common Lisp:

    import Data.Char
import Data.List
import Text.Html
-- from http://fawcett.blogspot.com/2007/08/roman-numerals-in-haskell.html
import RomanNumerals

-- Simple roman numeral conversion; returns "" if it cannot convert.
rom :: Int -> String
rom r = let m = toRoman r
        in (map toUpper . maybe "" id) m

-- Group a list N elements at a time.
-- groupN 2 [1,2,3,4,5] == [[1,2],[3,4],[5]]
groupN n [] = []
groupN n xs = let (a, b) = splitAt n xs in a : (groupN n b)

pink = "pink" -- for convenience below; green is already covered by Text.Html

rom_table = table ! [border 0, cellpadding 4] << trs
    where
      -- a list of <tr> entries
      trs = map (rom_tr . map rom_td) rom_array

      -- generates a <tr> from a list of <td>s
      rom_tr tds = tr ! [align "right"] << tds

      -- generates a <td> given a numeral and a color
      rom_td (r, c) = td ! [bgcolor c] << r

      -- our 5 x 5 array (list x list) of numerals and colors
      rom_array = (groupN 5 . take 25) rom_colors

      -- a theoretically infinite list of pairs of roman numerals and colors
      -- (practically, though, the roman numeral library has limits!)
      rom_colors = zip (map rom [1..]) colors

      -- an infinite list of alternating green and pink colors
      colors = cycle [green, pink]

main = let s = prettyHtml rom_table 
       in putStrLn s

    I should note there's also a little combinator library in Text.Html for composing tables using "above" and "beside" operators to calculate row/column spanning, but it's a little too simplistic in terms of applying attributes to duplicate this example exactly, and we don't need the fancy splitting of rows and columns.

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