Excluding column names from a listing

Rails
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 %>

<%= column.human_name %>

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

<%= column.human_name %>

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

4

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.

5

Hi –

On Tue, 26 Dec 2006, matt wrote:

<%= column.human_name %>

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

<%= column.human_name %>

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| %>
<%= name %>
<% end %>

David

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