Embracing Ruby on Rails

What is Rails and why would you want to use it over the myriad of other web application frameworks? From the website: Rails is a full-stack framework for developing database-backed web applications according to the Model-View-Control pattern. However, the second question is much harder to answer and is at the heart of a much heated debate in the developer community. Every developer has their favorite tool, framework, web server, text editor, etc… Moreover, the will vehemently defend their selection regardless of the faults of their platform of choice. In all honestly, I am just like other developers. I have my favorites and I often find my self trying to deploy it no matter how inappropriate a choice it may be. With my last design, I was finding Perl more and more of a hinderance than alleviating the workload. That’s not to say that Perl is not a great option for developing web software. However, my choice of programming language (Perl) and framework (CGI::Application) were just not created for what I wanted to do. Originally, I was very please at how lightweight CGI::Application was, but in the end, it was that fact that lead me to look elsewhere. Now there were plenty of other Perl frameworks for me to consider: Maypole, Catalyst and Jifty, Woodstock, and who knows how many others by now. After all the Perl mantra is <acronym title="there is more than one way to do it">TIMTOWTDI</acronym>. So why did I abandon Perl? David Cross sums up the main reasons in his post <a href="http://www.oreillynet.com/onlamp/blog/2006/05/mvc_frameworks_in_perl.html">MVC Frameworks in Perl</a>, fragmentation. All of these Perl frameworks work great in some niche areas and suck in others. Having all these options is great in once sense as you can choose the tool that best fits your initial idea of what you need to accomplish. However, what I set out to do very rarely resembles my finished product and I often find myself struggling to accommodate my new vision with the set of restrictions I have imposed upon myself by selecting a certain tool. I had a similar instance a few years ago when I switched my templating system from HTML::Template to Template::Toolkit. My needs grew, and although I could accomplish them with my original choice, it be increasingly obvious that a different solution would be a better fit. With Ruby, Rails is your only choice and because of that the ceiling of what you can accomplish is much higher. However, although I have not yet hit it, there are plenty of people who have. So what is my impression of Ruby on Rails after creating my first real site? Do I think it lived up to all the hype? Yes and no. I certinally can’t deny that it is very powerfuly MVC framework. However, there are certain aspects, especially coming from the Perl developer community, that I found quite lacking. First there is no Ruby equivalent of <a href="http://www.perlmonks.org">Perl Monks</a>. While similar sites do exist, such as <a href="http://www.railsforum.com">RailsForum</a>, they are no where near as complete or active. I would often post some perplexing problem and get a slew of high quality answers within the hour, sometime even big shots in the community itself (for instance perl Randal Schwartz, one of the authors of the Perl O’Reilly books is an active member). Second, I missed <a href="http://www.cpan.org">CPAN</a>. Rails plugins are found everywhere from RubyForge to the person svn servers of the developer. However, I do believe that <a href="http://www.github.com">GitHub</a> is going to change this fragmentation. It is a great collaboration tool. Finally, all of the hype has caused a flow of developers to the platform, a large majority of whom are first time programmers. Now a huge influx of developers is usually not a bad thing for any programming language, but because many of them are inexperienced, it makes it harder to find definitive answers. Everyone is still searching for ways to do it themselves. However, when this developer base matures, this will become a great asset. My website has always been a personal project designed for me to grow in my programming skills. Throughout the years I had become very comfortable with Perl. Unfortunately, with comfort comes stagnation. By choosing Rails, I was in effect choosing to learn a whole new paradigm, programming language, and join a whole new developer environment. I may eventually go back to Perl, but if my experience with designing this site are any indication of the future, I think I will be sticking with Ruby on Rails for quite some time.

2008-06-09T22:46:01Z

1 There has been so much hype surrounding Ruby on Rails. Even the mailing list for my beloved CGI:Application framework was being littered with posts comparing the two or about how to make thinks more railsesque. But on the other hand, I had spent so much time coding my previous site engine in Perl and perfecting it that I didn’t know if it would be worth the effort to learn a new platform, a new language with a different set of idioms, and rewrite working code. Well in about two months (my first commit was April 6th), I have a working site that is nearly feature comparable (and in some cases far surpasses) with my previous design. Rails really is a very powerful web development platform. embracing-ruby-on-rails Embracing Ruby on Rails

2008-06-16T14:59:54Z

1 [latex]\LaTeX{}[/latex] is the permier typesetting tool of the engineering and math world. It allows you to create beautifully typeset mathematical documents with a minimal learning curve. So why would you care about this on the web? Well for one, there really is no way to typset math in a browser. Sure there is <a href="http://www.w3.org/Math/">MathML</a> but that is supported by only a few browsers nativly, most will require a plugin (if even available). So how should one go about doing this, ensuring that the math formulas will be seen by the widest possible auidence? Use images! Every browser can render an image, so if we are able to take the LaTeX and render it as an image, we will be set. This is exactly the approach taked by <a href="http://www.mayer.dial.pipex.com/tex.htm">LatexRender</a>, a set of scripts for rendering LaTeX in <a href="http://www.php.net/">php</a> programs. Unfortunatly, as far as I know, there is not drop in solution for Ruby. However, there were a few projects that pointed me in the right direction. Most noteable was redsymbols <a href="http://redsymbol.net/software/l2p/">l2p</a> Perl script and the afformentioned LatexRender. I have already done the hard stuff for you and put it up on my GitHub <a href="http://github.com/mpetnuch">repository</a>. <pre><code class="multiline_code">$> git clone git://github.com/mpetnuch/latex-renderer.git vendor/plugins/latex_render</code></pre>You also need to make sure that you have the RedCloth Ruby Gem and a LaTeX package for the <a href="http://github.com/mpetnuch/latex-renderer/tree/master">Latex Render plugin</a> installed. Next we need to write our own custom RedCloth. I am going to call it Washcloth since it is cleaning up the site. Create a new file called washcloth.rb in your projects lib directory with the following contents: <pre><code class="multiline_code">class Washcloth < RedCloth LATEX_START_CODE = /\[latex\]/i LATEX_END_CODE = /\[\/latex\]/i LATEX_RE = /\[latex\](.*)\[\/latex\]/i RULES = [:block_textile_table, :block_textile_lists, :block_textile_prefix, :inline_textile_image, :inline_latex, :inline_textile_link, :inline_textile_code, :inline_textile_span, :glyphs_textile] def inline_latex( text ) # Don't do anything unless we have same number of start/end tags if text.scan(LATEX_START_CODE).size == text.scan(LATEX_END_CODE).size text.gsub!( LATEX_RE ) do |m| latex = LatexRenderer.new latex.formula = $1 begin filename = latex.process md5 = latex.md5hash # if the processing was successful we just display the rendered image sprintf '<img src="%s" alt="latex image" />', filename.gsub(/.*?\/images/, '/images') rescue => e sprintf('%s', latex.formula) end end end end def to_html super(*RULES) end end</code></pre>Let’s test it out. Fire up the console: <pre><code class="multiline_code">>> latex = '[latex]x^2 + y^2 = z^2[/latex]' => "[latex]x^2 + y^2 = z^2[/latex]" >> r = WashCloth.new latex => "[latex]x^2 + y^2 = z^2[/latex]" >> r.to_html => "<img src="/images/latex/image.png" />"</code></pre> So we see that our [latex]\LaTeX{}[/latex] is replaced with a link to a rendered image of the code. All that is left is to replace any instance of RedCloth in your program with WashCloth and it will automatically render the LaTeX in your views. What if you use something like Err the Blog’s <a href="http://errtheblog.com/posts/12-actsastextiled">acts_as_textiled</a>? You going to have to edit the plugins source and change RedCloth to WashCloth, but that’s it! So what have we accomplished? We can now render latex commands inline with our Textiled HTML. For instance, the following command: <pre> [latex] $$\Gamma(s) \zeta(s) = \int_0^{\infty} \frac{x^{s-1}e^{-x}}{1-e^{-x}}\,dx$$ [/latex] </pre>Will render as: [latex]$$\Gamma(s) \zeta(s) = \int_0^{\infty} \frac{x^{s-1}e^{-x}}{1-e^{-x}}\,dx$$[/latex]

2008-06-16T03:37:49Z

7 <a href="http://whytheluckystiff.net/ruby/redcloth/">RedCloth</a> is Ruby’s Textile module. Textile is a lightweight markup language originally developed by Dean Allen that allows a user to create well-formed styled XHTML. This site employes the RedCloth Textile module through the <a href="http://errtheblog.com/posts/12-actsastextiled">acts_as_textiled</a> plugin. The nice thing about RedCloth is it is faily easy to extend the markup which it recognies. In this tutorial, I am going to show you how to render [latex]\LaTeX{}[/latex] in your site by extending RedCloth. extending-redcloth Extending RedCloth

2008-12-01T00:15:21Z

48 As with the LaTeX problem, I wanted something that could integrate with what I was alreadying using. Parsing the entire text twice was just not an option. RedCloth was already identifying the <code>pre</code> and <code>code</code> blocks because it doesn’t textilse those. I just had to figure out how to intercept and then stylize them. I came across <a href="http://rpheath.com/">Ryan Heath’s blog</a> and his code snippits instantly caught my eye. I shot him an email and asked him what he was using to preform the syntax highlighting. Turned out he was using the Ruby Syntax <a href="http://syntax.rubyforge.org/">gem</a>. Apparently, he tried out <a href="http://ultraviolet.rubyforge.org/">UltraViolet</a>, but couldn’t get it to run on his hosts’ server. I think the UltraViolet gem was overkill for what I wanted to accomplish and that the Syntax gem was just what I needed — simple and fast. Now that I found the tool sytlizing code, I needed to intercept the <code>code</code> blocks from RedCloth. After a little bit of fishing around in the RedCloth <a href="http://redcloth.rubyforge.org/">documentation</a>, I found the function I needed to override: rip_offtags. Before we can begin though, we have to install the Sytax gem. Preform the following on the command line: <pre><code class="multiline_code">> sudo gem install syntax</code></pre>The syntax gem contains a function called <code>convert</code> which takes code and tranforms into HTML with each token of the code put into spans. It is very simple to use. The following is taken directly from its docs: <pre><code class="multiline_code">require 'syntax/convertors/html' convertor = Syntax::Convertors::HTML.for_syntax "ruby" html = convertor.convert( File.read( "program.rb" ) ) puts html</code></pre>From the above, you can see that once we are able to intercept the code blocks from RedCloth, we just pass it onto the <code>convert</code> function and we are done. We are now ready to edit the washcloth.rb file we created when making the LaTeX extension. Add the following to the very begining of the file (before the class tag): <pre><code class="multiline_code">require 'syntax/convertors/html' # for the syntax gem</code></pre>Next we need to copy the existing rip_offtags defintion from redcloth.rb. <pre><code class="multiline_code"># File lib/redcloth.rb, line 1009 OFFTAGS = /(code|pre|kbd|notextile)/ OFFTAG_MATCH = /(?:(<\/#{ OFFTAGS }>)|(<#{ OFFTAGS }[^>]*>))(.*?)(?=<\/?#{ OFFTAGS }|\Z)/mi def rip_offtags( text ) if text =~ /<.*>/ # strip and encode pre content codepre, used_offtags = 0, {} text.gsub!( OFFTAG_MATCH ) do |line| if $3 offtag, aftertag = $4, $5 codepre += 1 used_offtags[offtag] = true if codepre - used_offtags.length > 0 htmlesc( line, :NoQuotes ) unless used_offtags['notextile'] @pre_list.last << line line = "" else # this is the part that we're interested in htmlesc( aftertag, :NoQuotes ) if aftertag and not used_offtags['notextile'] line = "<redpre##{ @pre_list.length }>" @pre_list << "#{ $3 }#{ aftertag }" end elsif $1 and codepre > 0 if codepre - used_offtags.length > 0 htmlesc( line, :NoQuotes ) unless used_offtags['notextile'] @pre_list.last << line line = "" end codepre -= 1 unless codepre.zero? used_offtags = {} if codepre.zero? end line end end text end</code></pre>The code that were need to change is the following: <pre><code class="multiline_code">htmlesc( aftertag, :NoQuotes ) if aftertag and not used_offtags['notextile'] line = "<redpre##{ @pre_list.length }>" @pre_list << "#{ $3 }#{ aftertag }"</code></pre>The local variable, <code>aftertag</code>, contains the unformatted code that we are interested in. What is happening in that block, is RedCloth is passing it off to another function which escapes special characters. Since the syntax gem will do that for us we can use it’s convert function as a drop in replacement. Chage the above code to the following: <pre><code class="multiline_code">if aftertag and not used_offtags['notextile'] convertor = Syntax::Convertors::HTML.for_syntax "ruby" aftertag = convertor.convert(aftertag, false) end line = "<redpre##{ @pre_list.length }>" @pre_list << "#{ $3 }#{ aftertag }"</code></pre>Notice that my call to convert has a second parameter set to <code>false</code>. This is because we already have <code>pre</code> and <code>code</code> tags that RedCloth is going to insert back in for us. Setting the second paramter to <code>false</code> tells convert to not add in <code>pre</code> tags. The only thing left to do is write some custom CSS to tell the browser how we want to style our tokens. <a href="/stylesheets/code.css">Here</a> is a good starting point. Just edit the colors to fit the scheme you have for your own site! <h4>Update:</h4> There is a bug in the current implementation. For instance if you have a <code>pre</code> tag inside your <code>code</code> block, RedCloth will break it out and deal with it separately which then breaks your highlighting. Once solution would be to create <code>[code]</code> blocks like we did for LaTeX rendering, but I am not sure if I like that way. Have to think about this. If you have any good ideas, let me know and post it in the comments!

2008-06-18T00:59:03Z

8 After I implemented LaTeX rendering into my views, I was quite satisfied with how it came out. LaTeX can now be effortless inserted into a field that is textile enabled with very good results. But then I began to look at the code snippits and I realized how ugly they look when compared to the rest of the site. I did a quick web search for ways to incorporate syntax highlighting in Rails applications, but I wasn’t really satisfied with what I found. Then the solution smacked me in the face. Just extend RedCloth! syntax-highlighting-with-redcloth Syntax Highlighting with RedCloth

2008-12-01T01:14:52Z