Tapestry

h1. Customization

h2. Overriding Default Views, Partials, Templates, etc.

It is possible to override any Rails view in the application by mimicking the directory structure in @app/views@ but under another folder @site_specific/app/views@. For example, to use your own version of @_dashboard.html.erb@ in @app/views/pages@ you would put it in @site_specific/app/views/pages@.

You can override the @#{Rails.root}/site_specific@ folder itself with the environment variable TAPESTRY_OVERRIDE_PATH, so that the folder can be left entirely outside of the Tapestry code base.

It is important to understand that including this folder, any subfolders, and all files is _optional_. If you do not wish to override a particular view, leave it out of the override folder.

h3. Caveat

_This statement to be followed up after more investigation._

It is my impression that when using multiple paths that the technique of using @explicitly_unloadable_constants@ for having files reload without restarting the server will not work properly. This could mean that while developing these site-specific files that the server has to be restarted after each change.

h3. Overriding @lib@ Files

The same logic works for files in the override path under the @lib@ subfolder, i.e. either @#{Rails.root}/site_specific/lib@ or @#{ENV['TAPESTRY_OVERRIDE_PATH']}/lib@.

h2. Adding Custom Questions to the "Participation Consent" Form

Currently this text and form are found in @views/participation_consents/show.html.erb@. This currently saves the user's responses in the InformedConsentResponse model. There is in this model a field called "other_answers" that is a serialized Hash where any number of "dynamically defined" answers can be saved with keys of your choosing. To accomplish this you have to add form inputs that end up with a @name@ attribute that looks like (e.g. to record "age"): @other_answers[age]@ and it will be recorded in the "other_answers" Hash in the model under the :age key.

There is a view helper for creating radio boxes for the participation concept form using this "other_answers" field. Example:

<pre>

  <div class="consent-form-question">

    <p>

      Would you judge yourself to be sane?

      <%= radio_answers( 'sanity', [['0', 'No'],

                                    ['1', 'Sometimes'],

                                    ['2', 'Yes']] ) %>

    </p>

  </div>

</pre>

There are also helpers for text areas (@text_area_answer@) and standard input texts (@text_field_answer@). For example:

<pre>

  <div class="consent-form-question">

    <p>

      If sane only sometimes, please explain when and for what reason this occurs:

    </p>

    <p>

      <%= text_area_answer 'reason_sometimes_sane', { :cols => 60, :rows => 3 } %>

    </p>

  </div>

</pre>

h3. Adding Custom Validation of Your Custom Question

This is done by adding a site-specific validations file in the @lib@ "override" folder, in the @lib/site_specific/validations.rb@ module. First place the following code in the file:

<pre>

module SiteSpecific

  module Validations

    extend ActiveSupport::Concern

    # *Do not remove this +included+ block!* It is what works the magic.

    included do

      method_name = "#{self.name.to_s.underscore}_validations"

      validate method_name if method_defined? method_name

    end

  end

end

</pre>

Then after this insert a method called @informed_consent_response_validations@ (after the name of the model relevant to the Participation Consent form). You can check @other_answers@ and add errors in the standard ActiveRecord way. For example:

<pre>

    def informed_consent_response_validations

      case self.other_answers[:sanity]

      when '2'

        errors.add( :other_answers, :sanity_not_permitted)

      when '1'

        if self.other_answers[:reason_sometimes_sane].blank?

          errors.add( :other_answers, :explain_occasional_sanity )

        end

      end

    end

</pre>

The messages should be placed in your locale file under:

<pre>

en:

  activerecord:

    errors:

      models:

        informed_consent_response:

          attributes:

            other_answers:

              sanity_not_permitted:

                You are not permitted to be sane.

              explain_occasional_sanity:

                Please explain when and why you are sometimes sane.

</pre>

See the documentation on [[Internationalization]] for where to put this.

h4. Automatic Reloading of the Validations Override During Development

As shown in the @development.rb.example@ file, you can add the following line to your @development.rb@ to have validation override changes automatically reload without having to restart your Rails server:

<pre>

ActiveSupport::Dependencies.explicitly_unloadable_constants << 'SiteSpecific::Validations'

</pre>