Question

This should be something simple but I’ve been at it for a day now and can’t see a clear answer.

I have three basic models: User, Evaluation and Job. Users work on the job and the job owner evaluates the users. A user can have many various jobs. Each job will evaluate its related users multiple times (within the job, each related user will have the same evaluations – with different scores, of course.)

So, simply, I would like to present the data in tabular form (kind of like an excel workbook) with the evaluation name going across the x axis and the user names going down the y axis.

So, it would look like this:

        Evaluation 1  |  Evaluation 2  |  Evaluation 3
       _______________________________________________________
User 1   Good              Poor            Outstanding
User 2   Poor              Good            Good

I can easily show the labels across either the x OR the y but not both.

Q1) Each Job/User Evaluation is its own db record. Any suggestions as to how I would structure the the LABELS across the x and y axis?

Q2) How would I ensure the data (for example, User 2 Evaluation 3) is categorized (plotted) correctly? And, what if a new User (e.g., User 3) joins the job late and doesn’t have Evaluation 1 or Evaluation 2…

Any and all suggestions are welcome!

Answer 1

One way of doing it is to create an array of hashes, each hash containing user rating and an array of all available evaluations, something like

Evaluation.where(:job_id => 1)order('title').map{|e| e.title}.uniq

This will give you something similar to all_evaluations:

all_evaluations = ['eval1', 'eval2', 'eval3', 'eval4']

User evaluations hash would look something like this:

user_evaluations = {"UserA"=>{:eval1=>1, :eval3=>3}}, {"UserB"=>{:eval1=>1, :eval=>3}}

all_evaluations will be used for header row labels and for pulling evals for each user records:

<tr>
<% all_evaluations.each do |eval_header| %>
  <td><%= eval_header %></td>
<% end %>
</tr>

<% user_evaluations.each do |user| %>
  <tr>
    <td><%= user.keys %></td>
    <% all_evaluations.each do |eval| %>
      <td><%= user.values.first[eval.to_sym] %></td>
    <% end %>
  </tr>
end

There might be few bugs/changes here, but it should work in principal.