generate nested_form.js file when installing plugin, could use some work

install.rb

@@ -0,0 +1,52 @@
+path = "public/javascripts/nested_form.js"
+puts "Generating #{path}"
+File.open("#{Rails.root}/#{path}", "w") do |file|
+  file.print <<-EOS
+$(function() {
+  $('form a.add_nested_fields').live('click', function() {
+    // Setup
+    var assoc   = $(this).attr('data-association');           // Name of child
+    var content = $('#' + assoc + '_fields_blueprint').html(); // Fields template
+    
+    // Make the context correct by replacing new_<parents> with the generated ID
+    // of each of the parent objects
+    var context = ($(this).parents('.fields').children('input:first').attr('name') || '').replace(new RegExp('\[[a-z]+\]$'), '');
+    
+    // context will be something like this for a brand new form:
+    // project[tasks_attributes][1255929127459][assignments_attributes][1255929128105]
+    // or for an edit form:
+    // project[tasks_attributes][0][assignments_attributes][1]
+    if(context) {
+      var parent_names = context.match(/[a-z]+_attributes/g) || []
+      var parent_ids   = context.match(/[0-9]+/g)
+      
+      for(i = 0; i < parent_names.length; i++) {
+        if(parent_ids[i]) {
+          content = content.replace(
+            new RegExp('(\\[' + parent_names[i] + '\\])\\[.+?\\]', 'g'),
+            '$1[' + parent_ids[i] + ']'
+          )
+        }
+      }
+    }
+    
+    // Make a unique ID for the new child
+    var regexp  = new RegExp('new_' + assoc, 'g');
+    var new_id  = new Date().getTime();
+    content     = content.replace(regexp, new_id)
+    
+    $(this).parent().before(content);
+    return false;
+  });
+  
+  $('form a.remove_nested_fields').live('click', function() {
+    var hidden_field = $(this).prev('input[type=hidden]')[0];
+    if(hidden_field) {
+      hidden_field.value = '1';
+    }
+    $(this).closest('.fields').hide();
+    return false;
+  });
+});
+EOS
+end

lib/nested_form/builder.rb

@@ -4,7 +4,7 @@ def link_to_add(name, association)
       @fields ||= {}
       @template.after_nested_form do
         model_object = object.class.reflect_on_association(association).klass.new
-        @template.concat('<div style="display: none">')
+        @template.concat(%Q[<div id="#{association}_fields_blueprint" style="display: none">])
         fields_for(association, model_object, :child_index => "new_#{association}", &@fields[association])
         @template.concat('</div>')
       end

spec/nested_form/builder_spec.rb

@@ -29,7 +29,7 @@
       mock(@template).after_nested_form { |block| block.call }
       @builder.fields_for(:tasks) { @template.concat("Task") }
       @builder.link_to_add("Add", :tasks)
-      @template.output_buffer.should == '<div style="display: none"><div class="fields">Task</div></div>'
+      @template.output_buffer.should == '<div id="tasks_fields_blueprint" style="display: none"><div class="fields">Task</div></div>'
     end
   end
 end