Archive for June, 2009

inspecting a many_to_many datamapper relationship object

June 25th, 2009 •
tags: ,

The output of calling inspect on a datamapper many_to_many relationship object is very informative

migrating to datamapper 0.10.0

June 3rd, 2009 • 17 comments
tags: ,

Some prerequisites to get ready for datamapper 0.10.0

You need to have at least rubygems 1.3.5
You need to have a reasonably fresh rspec

The following git instructions only apply if you want to keep track of the ongoing datamapper development.
You can safely omit them if you followed the instructions in the original post to the google group.

sudo gem install addressable
mkdir git-sources
cd git-sources/
git clone git://github.com/datamapper/extlib.git
git clone git://github.com/datamapper/do.git
git clone git://github.com/datamapper/dm-core.git
git clone git://github.com/datamapper/dm-more.git
git clone git://github.com/snusnu/merb.git
cd extlib/
rake install
cd ..
cd do/data_objects/
rake install
cd ../do_sqlite3/
rake install
cd ../do_xxx/
rake install
cd ../..
cd dm-core/
rake install
cd ..
cd dm-more/
rake install
cd ..

Migrating your app to datamapper 0.10.0 is pretty painless,
you mainly need to deal with deprecation notices:

options[:class_name] is now options[:model]
PropertySet#has_property? is now PropertySet#named?
update_attributes is now update and doesn’t support the *allow_attributes parameter anymore
new_record? is now new?
:mutable => true on a has(n, :things, :through => :others) relationship is not supported/necessary anymore
:remote_name option for has(n, :things, :through => :others) is now called :via
:some_property.in => ['val1', 'val2'] is not supported anymore in queries, just use :some_property => ['val1', 'val2']
belongs_to :parent now defaults to :nullable => false
When adding to associations, post.comments.build(...) is now post.comments.new(...)

If you’re using merb and you’re fine using the master branch (upcoming merb-1.1) and not the latest release, all you need to do is update your wycats/merb clone or run the following commands.

cd git-sources/
git clone git://github.com/wycats/merb.git
cd merb
sudo rake install

If you however want to use datamapper 0.10.0 with latest merb release (1.0.12 at the time of writing) you will currently need to run these commands (Thx again teamon for taking the time to backport stuff!).
merb-1.0.13 will be released soon and will be fully compatible with datamapper 0.10.0.

cd git-sources/
git clone git://github.com/wycats/merb.git
cd merb
git checkout -b 1.0.x --track origin/1.0.x
sudo rake install

You will maybe get some warnings about merb-more but you can safely ignore them.