Test Driven Ajax (on Rails)

Simulate Ajax Server Hits with xhr :get

If we double-click on that DIV, Ajax.Updater calls /wiki/-edit_node, and that doesn't work yet. So now test-first its behavior. It should return a FORM to edit this DIV:

  def test_wiki_yaml_action
    yaml_to_xhtml(get_omap)

    xhr :get,
        :edit_node,
        :page_name => 'WikiTestPage',
        :ypath => 'node:test_uncle_wiggily:script'

    assert_xml @response.body

    assert_xpath '/form' do
      assert_xpath 'textarea[ @name = "node_contents" ]' do |node|
        assert_match /tests uncle wiggily/, node.text
      end
    end
  end

GUI Bug Confession

Our DIV responds to double-clicks, even after the editor displays. So double-clicking a word to select it will refresh the DIV, and throw our edits away! The fix is edit_node, which should send more JavaScript that erases the ondblclick attribute.

The test requires our WikiController to grow its very first method:

class WikiController < ApplicationController

  def edit_node
    yar = YarWiki.new(params[:page_name])
    y = YAML.parse_file(yar.yaml_path)
    x = Builder::XmlMarkup.new
    params[:ypath] =~ /^node(:.*)/
    ypath = $1.gsub(':', '//')

    x.form do
      x.textarea :name   => 'node_contents',
                 :cols   => 60,
                 :rows   => 3 do
        x.text! y.select(ypath)[0].value
      end
    end

    render :text => x.target!
  end
end

Ajax Action Guards

All actions that serve Ajax should start with:

  return unless (request.xhr? or RAILS_ENV != 'production')

This prevents everyone from calling that action except Ajax events and tests. (I have omitted them in the interest of space.)

That code had to reconstitute an HTML ...