View Mapper: Scaffolding for your models and plugins

October 1st 2009 —   Comments and   Reactions

View Mapper will generate scaffolding illustrating how to write view code using a specified plugin or feature with your existing models. It can also generate new models.

A couple simple examples:

script/generate view_for office --view auto_complete:address

… will generate Rails scaffolding code that displays a form for an existing “office” model, with auto complete on the “address” field.

script/generate scaffold_for_view office address:string code:string
                                  --view auto_complete:address

… will generate the same form, but also create the “office” model class file, a migration file containing the “address” and “code” columns, and other standard scaffolding files as well.

The idea behind View Mapper is that it’s easy to write simple, concise model classes representing your domain objects using ActiveRecord, but very hard to implement the corresponding views using a combination of HTML, Javascript Rails helper functions, routes, controllers, etc. If you’re not very familiar with a certain plugin you want to use in your app, View Mapper can help you get started in the right direction by generating a working example with scaffolding code.

If you’re developing a Rails plugin or gem it’s easy to write your own View Mapper module for your plugin’s users to call with View Mapper.

Code:   http://github.com/patshaughnessy/view_mapper

Install:

sudo gem install view_mapper

Usage:

Two generators are provided, called view_for and scaffold_for_view:

script/generate view_for model [ --view view_name:param ]

This will generate the specified view code for an existing model. The view_for generator will look for your model, inspect all of its columns and then generate standard Rails scaffolding containing a form field for each existing column.

If you also specify a view, then a custom view will be created using the specified Rails feature or plugin, using the specified parameter.

script/generate scaffold_for_view model attributes [ --view view_name:param ]

If you don’t specify a view, then this command is identical to the standard Rails scaffold generator.

If you do specify a view, then the entire working set of a model, views and controller will be generated to implement the specified Rails feature or plugin, using the specified parameter.

Views:

Right now, I’ve implemented eight views:

  • auto_complete: Uses the standard Rails auto_complete plugin to implement type ahead behavior for the specified field.
  • paperclip: Uses the Paperclip plugin to upload and download file attachments.
  • has_many: Displays a complex form to edit two or more associated models.
  • has_many_auto_complete: This is the same as has_many but also uses the auto_complete plugin to implement type ahead behavior for each text field. This view requires you to install my fork of the Rails auto_complete plugin.
  • belongs_to: Generates scaffolding that allows you to select an existing, associated model.
  • belongs_to_auto_complete: Generates scaffolding that allows you to select an existing, associated model using auto_complete.
  • has_many_existing: Generates scaffolding for a complex form to edit two models that have a has_many, :through association with a third model. Use this if you have a many-many relationship with existing data.
  • (Default) If no view is specified, then standard Rails scaffold code will be generated.

I’ll be implementing more views in the coming weeks and months. There is also an API for implementing your own View Mapper module, for example to generate code illustrating how to use a plugin or gem you are working on. In the future I’ll document this as well.