Save all user entries from html text built off a loop using ruby and sinatra

Question

I am creating a web page that displays a table. It also has four columns at the end of each record that are text fields where the user can enter data. When the user hits the submit button at the bottom I want to save all the data in all the text fields and add it to my table. How can I save the data for all the text fields? Here is my code.

<h1>Testing Table</h1>
<form action="/table/" method="POST">
<table>
<thead>
<tr>
 <% event_column.each do |header| %>
    <th>
      <%= header %>
    </th>
  <% end %>
</tr>
</thead>
<tbody>
<% events.each do |event| %>
  <tr>
  <% event = event.first(14) %>
  <% event.each do |key, value| %>
    <td>
    <%= value %>
    </td>
  <% end %>
    <td><input type="text" name="event_description"></td>
    <td><input type="text" name="event_type">
    <td><input type="text" name="event_class">
    <td><input type="text" name="issue_expert"></td>
  </tr>
<% end %>
</tbody>
</table>
<br/>
<input type="submit">
<% ActiveRecord::Base.clear_active_connections! %>
</form>

I understand my issue. Since I am using the same variable to write all of the user entered columns when I try displaying in my POST method

<td><%= params[:event_description] %></td>

It will only display the last value entered because it's being reused. Is there anyway that when I hit submit I can loop through all the html text fields and save all the data? I'm pretty stuck here and I've searched all around. I understand how to save the text entry for the last row but, I don't know how to save all the text entries. I'm new to sinatra so I must be doing something fundamentally wrong.

Answer 1

By default when Sinatra (using Rack) parses the form data then if there are any duplicate keys then the last one is used and overwrites the others. However if you use a name that ends with [] then Sinatra instead creates an array containing all the entries with that name.

So in your case you need to change the names of the input elements:

<input type="text" name="event_description[]">

(and similarly for the others). Note the [] at the end of the name.

Now when you submit the form, params['event_description'] will be an array containing all the items submitted to the event_description input elements.

The Sinatra/Rack query parsing is actually more sophisticated than this, so you can go further with your form. In your loop you could do something like this:

<td><input type="text" name="events[][description]"></td>
<td><input type="text" name="events[][type]">
<td><input type="text" name="events[][class]">
<td><input type="text" name="events[][issue_expert]"></td>

Now when you submit the form and it is parsed, params['events'] will contain an array of hashes, each with keys description, type, class and issue_expert. You can then iterate over this array and process the data as appropriate. You may want to add a hidden id input with each hash to make sure each set of data is associated with the correct record (it might look something like <input type=hidden name="events[][id]" value="<% event.id %>">).