Excluding column names from a listing

rubyonrails-talk
1

I have a Listing model that I know I don't want to display a few of the columns, but I don't want to hard-code the columns that I do want either.

Is there a way to exclude certain columns?

This is what I have: <% for column in Listing.content_columns %>     <th><%= column.human_name %></th>

This is roughly what I want (in midnight pseudo-code): <% for column in Listing.content_columns[exclude: column_1, column_2] %>     <th><%= column.human_name %></th>

do-able?

Matt

2

Why not just customize your code instead of relying on the scaffolding?

RSL

3

Usually, it is better to make your own view instead of using the scaffold, but sometimes it's easier just to use the scaffolding.

What I did was override the content_columns method. Just take the source:

def content_columns     @content_columns ||= columns.reject { |c| c.primary || c.name =~ /(_id|_count)$/ || c.name == inheritance_column } end

And add the column names you want to exclude in the regex with _id and _count.

Jason

matt wrote:

4

Hi --

I have a Listing model that I know I don't want to display a few of the columns, but I don't want to hard-code the columns that I do want either.

Is there a way to exclude certain columns?

This is what I have: <% for column in Listing.content_columns %>   <th><%= column.human_name %></th>

This is roughly what I want (in midnight pseudo-code): <% for column in Listing.content_columns[exclude: column_1, column_2] %>   <th><%= column.human_name %></th>

do-able?

Absolutely!

I'd say what's missing is a content_columns_names method (at least I can't find one). It would look something like this:

   class ActiveRecord::Base      def self.content_column_human_names        content_columns.map {|c| c.human_name }      end    end

You could put that into a plugin, or just roll it into your application code (as below). In either case, it's probably best to put the array operation in the controller, which is a better place for dynamic determination of names you don't want.

So the whole thing might look like this (untested, and partially pseudo-code):

In the controller:

   def my_action      excludes = figure_out_which_names_you_don't_want      all_names = Listing.content_columns.map {|c| c.human_name }      @header_names = all_names - excludes    end

And in the view:

   <% @header_names.each do |name| %>      <th><%= name %></th>    <% end %>

David

5

Thanks,

That's the hint I've needed. Hadn't even thought about writing my own method.

I've read in numerous books/articles *not* to put the code in the view..... and look what I was trying to do.

Thanks again.