From: Philip Mak <pmak@...>
Date: 2002-11-09T17:47:21+09:00
Subject: An alternative HTML generation syntax

I'm using Ruby to output HTML a lot these days. I know of these
methods:

1. Use CGI::Html4. Problem: Must use '+' all the time to join things.
If I forget a '+', everything in the block before the '+' will get
silently ignored since only the return value matters.

2. Manually using puts or print statements. I get tired of having to
type 'puts' all the time.

3. Use eruby. Problem: Can't seem to use this inside methods.

I'm trying to come up with another method of HTML generation that
minimizes typing and is readable.

Here's an example. Instead of this piece of code:

puts "<p>"
puts "NEW!" if flag == 'new'
puts "UPDATED!" if flag == 'updated'
puts "<br>"
if numparts > 1
    puts "Parts:"
    (1..numparts).each do |i|
        puts %Q{ <a href="#{i}.asp">[#{i}]</a>}
    end
end
puts "by #{author.display}" if author
puts "</p>"

It would be this:

HTML.new { p {
    t 'NEW!' if flag == 'new'
    t 'UPDATED!' if flag == 'updated'
    br
    if numparts > 1
        t 'Parts:'
        (1..numparts).each do |i|
            a(:href => "#{i}.asp") { "[#{i}]" }
        end
    end
} }

The HTML class would be something like this:

class HTML
    def initialize(&block)
        @buff = ''
        self.instance_eval &block
        puts @buff
    end

    def p
        @buff += "<P>#{yield || @buff}</P>"
    end
    # define a, h1, h2, etc. and all the other HTML tags similarly
end

Whenever an HTML function (like "p" or "a") is called, it will
generate some HTML code and tack it onto a buffer. Finally at the end,
the contents of the buffer are returned.

Any thoughts on this? Do you like the interface to my HTML class (can
it be made any easier)? Are there any other HTML-generation-with-Ruby
methods that I missed?