Re: Tales from the Dark Side

Ian Joyner wrote:
> On 17/03/2006, at 4:47 PM, Peter McGregor wrote:
>
>> Hello
>>
>>
>> Ian Joyner wrote:
>>> Strange how Apple posted a note about Ruby on Rails in their latest 
>>> ADN (http://developer.apple.com/tools/rubyonrails.html). So, I had a 
>>> look. Seems to be very text and terminal based from the tutorial 
>>> with no tools like WO Builder, so you end up hand crafting the html 
>>> with <% ... %> rails tags instead of WebObject tags automatically 
>>> provided by WOB.
>>>
>>> Installation was somewhat tedious as well taking about an hour (but 
>>> straightforward). Ruby is reasonably simple, considering it has 
>>> syntactic elements of LISP, perl, Java, and Eiffel. Treating line 
>>> breaks as statement terminators is a throw back to the 1950s – 
>>> that's why ALGOL introduced the semi-colon (which Ada and Eiffel 
>>> realised was unnecessary anyway if the syntax were regular enough, 
>>> and also that begins were unnecessary, you only need ends, like 
>>> Ruby, but it mixes in { and } just to keep C people happy I guess). 
>>> Then again C defines don't get this right either also requiring line 
>>> continuations (whoever stole the idea of defines from Burroughs 
>>> ALGOL missed the subtle point that the # terminates the define, not 
>>> starts it!)
>>>
>>> The MVC separation was nice, but you get that in WO components 
>>> anyway. I didn't see that you could do desktop apps in rails like 
>>> WO. Is there an equivalent of EOModeler so you can get your model 
>>> right first?
>>>
>>> Still, not bad as a simple object-relational system for simple web 
>>> pages. Don't know how it would scale up though. They said migrations 
>>> were database agnostic, but that is the point of SQL anyway (to be a 
>>> standard). Perhaps just nicer to work with than SQL, but still text 
>>> based rather than entity based as in EOModeler.
>>>
>>> Anyone else have real experience with it?
>>>
>> Rails doesn't persist sessions like WebObjects or Tapestry.
>> The sessions are more like java servlet sessions.
>> So the objects have to be manually retrieved and saved in the session 
>> area in every method(submit) call.
>>
>> Ruby is very dynamic. The downside of this is if there is something 
>> wrong in the code the Ruby instance may decide to just stop
>> without any warning. eg if there is a syntax error in a database 
>> model the browser will just return a blank page. There won't be any
>> error messages in any log files. There are ways though to find 
>> database errors. Just fire up irb and access/trigger the model 
>> outside the web application.
>
> So Ruby is a scripting language. Does it compile at all (at least as 
> far as being able to precheck all code branches for errors, not 
> necessarily code generation, a bit like WFL)? 
Currently Ruby doesn't compile but the the creator of Ruby, and others, 
are converting Ruby into a byte code vm, like Java.
Its called Ruby done rite.
There is someone doing an Eclipse plugin for ruby who is incorporating 
some sort of syntax checking. From memory I think he
is using a port of Ruby that runs on the Java VM, to help with building 
some sort of syntax tree.


> I'd guess there's no type checking so that significant source of 
> errors could get through. 
When an error does occur there is no stack trace, as with java, so 
sometimes its hard to know what is going on.

Rails is just one of many web frameworks built on Ruby. IOWA is another 
web application framework that uses continuations,
which means that class variables are persisted during the 
request/response loop. CGIKIT is also built on Ruby and is very similar 
to the WebObjects presentation layer.

I think the Rails presentation layer could be improved. eg there is no 
way to have multiple submit buttons in a form with the Rails
API. Special text strings have to be added to the id= or name= fields in 
the html tags to pass this information to a central method.
This method then has to decode the input parameters to decide what 
actual method to call.
I figured out how to do this because I did a google search and saw a 
reply to a question that had been asked by another former webobjects 
person. The question was about multiple submit buttons.
> Don't think I like the prefixing variables with @ and : to denote what 
> kind of variable they are, but then scripting languages tend not to 
> have declarations where you would put such modifiers only once.
>>
>> With rails I liked being able to make a change in an rb file, save 
>> and then just refresh the browser. Its quite fast to develop in from 
>> that aspect. Maybe this is similar to what objective script in 
>> WebObjects used to be.
>
> Did seem pretty neat how you didn't have to build, but then there is 
> the downside as you say.
>>
>> Regards
>>
>> Peter
>>
>>> Ian
>
> _______________________________________________
> WebObjects-dev mailing list
> [email protected]
> http://www.omnigroup.com/mailman/listinfo/webobjects-dev