Web Development & Stuff » Ruby

Submit form with jQuery gotcha

admin — Thu, 29 Oct 2009 15:40:29 +0000

It seems that you can’t submit a form with jQuery using:

1	$('form#myform').submit();

If you have an input in the form with the name attribute set to submit. So this doesn’t work:

1	="submit" name="submit" value="Press to continue" />

Change the name attribute to something else other than submit and it works fine ;]

Will Paginate result / pages / totals helper

admin — Tue, 31 Mar 2009 09:17:36 +0000

This might be handy for anyone that’s using the Ruby on Rails will_paginate plugin/gem. It’s a helper that displays the result totals, current viewing range and page range based on an input Will Paginate collection array.

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def render_pagination_totals(will_paginate_collection=false)

  if will_paginate_collection and !will_paginate_collection.total_entries.zero?

  if will_paginate_collection.total_entries < (will_paginate_collection.current_page * will_paginate_collection.per_page)

    end_of_range = will_paginate_collection.total_entries

  else

    end_of_range = (will_paginate_collection.current_page * will_paginate_collection.per_page)

  end

  'Viewing ' + ((will_paginate_collection.current_page * will_paginate_collection.per_page) - (will_paginate_collection.per_page.to_i - 1)).to_s + ' to ' + end_of_range.to_s + ' of a total of ' + will_paginate_collection.total_entries.to_s + ' results. Page ' + will_paginate_collection.current_page.to_s + ' of  ' + will_paginate_collection.total_pages.to_s + '.
'

end

Usage:

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<%= render_pagination_totals(@will_paginate_collection) %>

# Output: Viewing 1 to 10 of a total of 17 results. Page 1 of  2.

Ruby on Rails error_messages_for quirks

admin — Tue, 24 Mar 2009 09:23:50 +0000

Don’t forget kids, error_messages_for seems only to like a symbol or a string of the instance variable name of your instantiated Active Record object (model). Not the object itself.

So this doesn’t work:

1	<%= error_messages_for(@instance_variable_name) %>

Neither does this but then again it shouldn’t! (blogging for my own records):

1	<%= error_messages_for('active_record_model_class_name') %>

This is what you want:

1	<%= error_messages_for(:instance_variable_name) %>

A string will do the same trick too:

1	<%= error_messages_for('instance_variable_name') %>

Ruby on Rails dynamic select menu with blank first option using select helper

admin — Mon, 23 Mar 2009 14:24:23 +0000

Managed to create a dynamic select menu with this code today. It includes a blank first value:

1	<%= select("event", "search_type", EventType.find(:all).collect {\|et\| [et.name, et.id] }.sort, { :include_blank => 'all' }) %>

Create a Ruby Hash from 2 arrays (ranges in this case)

admin — Mon, 23 Mar 2009 10:53:52 +0000

To create a Hash from a couple of Arrays you can do this in Ruby. I’m using a couple of Array ranges in this example.

OK the keys (strings):

1	keys = ('1'..'99').to_a

Now the values (integers):

1	values = (1..99).to_a

Now the instantiation of the Hash object from the 2 arrays:

1	hash = Hash[*keys.zip(values).flatten]

Ruby on Rails Hpricot parser- uninitialized constant SearchController::Hpricot

admin — Thu, 19 Mar 2009 12:32:59 +0000

I installed the Hpricot gem today from the Hpricot GitHub homepage. I tried to parse some XML and got this error:

1	uninitialized constant SearchController::Hpricot

Suddenly realised I should of required the library but the install documentation didn’t mention that. Managed to fix the issue with this line in my environment.rb

1	config.gem "hpricot"

Nested form labels / inputs technique using Ruby on Rails form helpers

admin — Wed, 18 Mar 2009 16:36:37 +0000

It was, (not 100% up on WAG2 yet) a W3C WAI accessibility recommendation to nest your form fields (inputs/selects etc) inside your label tags. So they were contained by the label much like you’d put an tag inside an tag to make it a link.

The Rails helpers don’t seem to have much scope for this (please correct me) but it is hack-able doing some concatenation stuff like this:

1	<%= f.label "Screen name:" + (f.text_field :screen_name) %>

Adding class attribute to Ruby on Rails form_for helper

admin — Wed, 18 Mar 2009 16:27:09 +0000

Following on from my last post, sorry folks a bit more Rails bashing. What happened to convention over configuration and the principle of least surprise?

So to add a plain old class attribute to a form tag using the form_for helper you need to do (notice this time we’re declaring the actual html options with the :html symbol):

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<% form_for(@user, :html => { :class => "class_name_here"} ) do |f| %>

  # Form goes here

<% end %>

Adding class attribute to Ruby on Rails form_tag helper

admin — Tue, 17 Mar 2009 09:53:39 +0000

Some days I love Rails, some days it really frustrates me.

Anyways spent 10 minutes remembering the syntax for the form_for helper to add a regular class attribute. The second hash of parameters are the HTML ones! Thought I’d blog it for my own records:

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<% form_tag( { :action => "destroy", :method => "delete" }, :class => "class_name_here" ) do %>

  #Form goes here

<% end %>

Ruby on Rails equivalent of PHP_SELF – request.path

admin — Fri, 06 Mar 2009 16:44:18 +0000

This in Ruby/Rails:

1	<%= request.path %>

Seems to be the equivalent of this in PHP:

1	$_SERVER['PHP_SELF']?>

Handy for submitting things to themselves with out any parameters being passed.