Different day, same shit: MySQL Gem again

Again, the MySQL ruby gem totally annyoed me trying to install it on a fresh Mac OS X 10.5.5 install and MySQL 5.0.67.

This time the following command brought it to life:

sudo env ARCHFLAGS="-arch i386" gem install mysql -- \
  --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib \
  --with-mysql-include=/usr/local/mysql/include

Thanks to a bitter software engineer.

Filed in English posts, Rails | Comments (1) »

11-Dec-08

Some random Grails thoughts and tipps

Lately i’ve been rambling and ranting a lot on twitter about the Grails framework.

To my surprise, many other developers actually read this tweets and helped me out on some problems. Thanks a lot gals and guys, i really appreciate that. Me rambling isn’t meant to be personal at any time, i guess you know how easily one gets frustrated with too less time and too much stuff to do.

Anyway, here are some shortcuts that could eventually be helpful. I’m gonna add more to this list the next days:

Enabling hibernate filters in the grails session

Took me a little digging through the source code, but i came up with the following idea:

import org.springframework.transaction.support.TransactionSynchronizationManager;
 
class SecurityFilters {
  def sessionFactory
  def filters = {
    login(controller:'*', action:'*') {
      before = {
        // get your user id somewhere
        def whatsoeveruserId = 0
        def sessionHolder =  TransactionSynchronizationManager.getResource(sessionFactory);     
        sessionHolder.getSession().enableFilter("filterByOwner").setParameter("currentUserId", whatsoeveruserId);
      }
    }
  }
}

I want to have some kind of rowlevel security through a Hibernate filter. Through dependency injection i get hold of the sessionFactory and through the TA Manager, i get the current session on which i can enable my filter.

Doing this in a Grails filter, i can combine this with some kinda login mechanism and i’m good to go.

Whitelisting attributes through bindData

To me it’s a bad idea using blacklisting on data binding as i can and will forget attributes that must not be updated through a webform.

With Marc i found the following solution:

bindData(entity, params, entity.properties.collect{it.key} - ['foo', 'bar'])

That way only attributes foo and bar gets updated.

Anyway, with Grails 1.1 this won’t be necessary anymore as Graeme anonced.

Graeme was so kind to comment on this: This feature is already in 1.0.x, i just didn’t find it, have a look at the docu at The Web Layer.

bindData(entity, params,  [include:['foo', 'bar']])

Updates on 2008/12/9

Adding custom errors to a domain class

The grails reference has a handy example for adding custom errors to domain classes, have a look here. This works quite well except that all other errors from databinding are mysteriously gone.

For me, the following steps worked to update a user (change some persistent attributes and the transient attributes password and passwordConfirmation):

bindData(anwender, params, [include:['name', 'vorname', 'password', 'passwordConfirmation']])
 
if(params.password != "" && params.password == params.passwordConfirmation)
  anwender.hashPassword() // As alway, never ever store plaintext passwords ;)
else if(params.password != "") {
  anwender.validate() // IMPORTANT without that step, possible other errors from bindData vanished
  anwender.errors.rejectValue('password', 'user.anwender.passwords_doesnotmatch')
}

Afterwords, hasErrors() show all errors, i.a. non nullable fields and the like.

More thoughts

I somewhat used to hibernate and come along very well with it, even though i’m actually a SQL fan. I guess if my inside into the Spring Framework would be a little bit deeper, some areas wouldn’t be hard to understand.

On the other hand i think that Grails does a great job for J2EE based development and it should do so even more. As always, there is the law of leaky abstractions, but the whole butload of stuff that is the J2EE stack should be abstracted away.

Updates on 2009/2/6

Grails 1.1-beta3

I use hibernate validator in my domain classes (that i created outside of rails as hibernate annotated classes) and i got

java.lang.NoSuchMethodError: org.hibernate.event.PreInsertEvent.getSource()Lorg/hibernate/engine/SessionImplementor

on every insert and update. Hibernate validator 3.0.0.GA is incompatible with the Hibernate version in Grails 1.1-beta3. Problem was gone after upgrading validator to 3.1.0.GA.

Some other stuff:

  • Installed plugins are obviously gone. i.e yui plugin is still in the application folder, it needs to be reinstalled after upgrade (grails install-plugin yui)

    Ok, i see this was done on purpose: “Plugins are now stored in your USER_HOME directory. You will need to re-install your plugins or run” (from the beta2 release note). Not a good decision making this a default imho. I like having my apps pinned to specific plugins.

  • The message method for doing I18n in controllers used to be available in filters. This method seems to be gone. No solution for that so far.
  • Values not bound in a form are not null anymore but 0 in case of numeric values. Bummer! Actually my bad.
  • Some problems solved.

Filed in English posts, Java | Comments (12) »

04-Dec-08

PDF::Writer and Ruby on Rails 2.2.2

If you followed the instructions here and used the method named PDF::Writer (Austin Ziegler), you we’re out of luck when Rails 2.1 appeared.

With Rails 2.2.2 once again the rendering mechanism seems to have changed big time and my previous post on how to make the pdf/writer gem work with a custom template handler doesn’t work anymore.

With the help of Josh Peek i was able to fix this. He gave me the following code to enable a rpdf template handler with pdf-writer:

module ActionView # :nodoc:
  require 'pdf/writer'
  class PDFRender < ActionView::TemplateHandler
    PAPER = 'A4'
    include ApplicationHelper                     
    include ActionView::Helpers::TranslationHelper
    include ActionView::Helpers::AssetTagHelper
    include ActionView::Helpers::TextHelper
    include ActionView::Helpers::TagHelper
    include ActionView::Helpers::UrlHelper
 
    def self.call(template)
      "ActionView::PDFRender.new(self).render(template, local_assigns)"
    end
 
    def initialize(action_view)
      @action_view = action_view
    end
 
    # Render the PDF
    def render(template, local_assigns = {})
      @action_view.controller.headers["Content-Type"] ||= 'application/pdf'
 
      # Retrieve controller variables
      @action_view.controller.instance_variables.each do |v|
        instance_variable_set(v,
        @action_view.controller.instance_variable_get(v))
      end
 
      pdf = ::PDF::Writer.new( :paper => PAPER )
      pdf.compressed = true if RAILS_ENV != 'development'
      eval template.source, nil, ''
 
      pdf.render
    end
  end
end
 
ActionView::Template.register_template_handler 'rpdf', ActionView::PDFRender

Just drop this under config/initializers and you’re fine.

Filed in English posts, Rails | Comments (8) »

24-Nov-08

RFC3339 revisited

Not just for ruby but also the corresponding formats for

Java

public static final SimpleDateFormat RFC3339_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");

and for Oracle

SELECT to_timestamp_tz('1979-21-09T06:54:00+01:00','YYYY-MM-DD"T"HH24:MI:SSTZH:TZM') FROM dual
/

Oracle

Filed in English posts, Java, Oracle | Comments (0) »

13-Nov-08