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Every toolkit has a screwdriver and this one is a cruciform.

Crushyform is a Sequel plugin that helps building forms. It basically does them for you so that you can forget about the boring part. The kind of thing which is good to have in your toolbox for building a CMS.

We tried to make it as modular as possible but with sensible default values.

I am also aware that this documentation is new and might lack some crucial information but feel free to drop me a line if you have any question.

By the way, I'd like to thank Jeremy Evans for answering so many questions on the #sequel IRC channel.


Crushyform is a Ruby Gem so you can install it with:

sudo gem install sequel-crushyform


Crushyform is also a Sequel plugin so you can add the crushyform methods to all your models with:

::Sequel::Model.plugin :crushyform

Or you can just add it to one model that way:

class BlogPost < ::Sequel::Model
  plugin :crushyform
  # More useful code from you

Once you have it, that is when the magic begins. You already can have a form for it: # Returns a nice form

This will return a form for your new model. Without any effort.
If you try with an existing entry, it works as well (wow!).
If you try with an entry that is not valid, error messages are incorporated (even more wow!).

Obviously you have a bit more control on that. To start with, this method have arguments which are:

  • List of columns (all of them by default)
  • Action URL (when nil, which is the default option, the fields are not wrapped in a form tag)
  • HTTP Method (POST by default)

So you can do that: [:title,:body], "/new_blog", "GET" ) # Returns a nice form

Which will return a form (wrapped this time) with only the 2 fields :title and :body. Options give the action URL and method.

Now say you want to have all the default options, but you want a wrapping form tag, you can do that: BlogPost.crushyform_schema.keys, "/new_blog" ) # Returns a nice form (a crushy form to be precise)

You have to put the default value Model.crushyform_schema.keys because in the order of priority, the list of columns is more important

This is due to the fact that in a real case scenario we are more likely to use the version without a wrapping form tag. Mainly because we want to add some other hidden inputs like a destination, a method override in order to generate a PUT request or a pseudo XHR value.

Another reason might be that you want to add other fields to the tag. The default tag is pretty basic.


Here is the list of CSS classes used in order to style the forms. That should be enough, drop me a line if you feel something is missing.

  • crushyfield-required is the class for the default required flag
  • crushyfield is used on the wrapping paragraph tag of every fields
  • crushyfield-error is used on the wrapping paragraph tag of a field containing errors
  • crushyfield-error-list is on the span that wraps the list of errors (is just a span, not an html list though)


As mentioned before, the form is more like a way to gather all the fields we're interested to have in a form. Which means you can have more control than that. You can have just one field at a time. In order to do that, you have 2 methods:

  • Model#crushyinput(column,options) which only gives you the input tag for the field
  • Model#crushyfield(column,options) which does the same but wrapped in a paragraph tag with a label and an error list

Regarding the options, you have plenty of them. We'll see later how we can set all of them in the crushyform schema but they all can be overriden when requesting the input tag. Here is the list of schema-related options:

  • :type is the crushyform type that is used for the field (default is :string)
  • :input_name is the name used for the input tag (default is model[columnname])
  • :input_value is the input value used for the input tag
  • :input_type is the input type used for the input tag (default is text when applicable)
  • :input_class is the class value used for the input tag
  • :html_escape has to be set to false if you do not want the value to be escaped (default is true)
  • :required text that says that the field is required (default is just blank). A ready-made value for that field is also available if you put true instead of a text. It is an asterisk with span class crushyfield_required

As you can see, a lot of things can be overriden at the last level. There is another option just for Model#crushyfield that is called :name. This is basically the name of the field in the label tag. By default, this is the name of the column in a human readable way, which means there are no underscore signs and foreign keys like :author_id will have the name: Author.

Here is an example:

BlogPost[4].crushyfield( :title , { :name => "Enter Title", :required => true })

This will give you a full field for the column :title with a label saying "Enter Title" and an asterisk that says the field is required. As mentioned before the :required can be the text to put, but for consistency, it is recommanded to wrap it in the same span with the class crushyfield-required. So if you want to simply write required:

<span class='crushyfield-required'> required</span>

But really this is good only if the text is different for that specific field. You usually want to override the class method Model::crushyfield_required. The default implementation is:

def self.crushyfield_required
  "<span class='crushyfield-required'> *</span>"


  • :string is the default one so it is used when the field is :string type or anyone that is not in the list like :integer for instance
  • :none returns a blank string
  • :boolean
  • :text
  • :date is in the format YYYY-MM-DD because it is accepted by sequel setters as-is
  • :time is in the format HH:MM:SS because it is accepted by sequel setters as-is
  • :datetime is in the format YYYY-MM-DD HH:MM:SS because it is accepted by sequel setters as-is
  • :parent is a dropdown list to chose from
  • :attachment is for attachments (who guessed?).
  • :select could be used for fields like String or Fixnum but giving a limited number of options


As you can see date/time/datetime field is a text input with a format specified on the side. We used to deal with it differently in the past, but nowadays this is the kind of field that is better to keep basic and offer a better interface with javascript. Better to give it a special :input_class through the options and make it a nice javascript date picker instead of trying to complicate something that is gonna be ugly at the end anyway.

Also if you want to use a proper time field (just time with no date), don't forget to declare it all lowercase in your schema. Otherwise it will use the Time ruby class which is a time including the date:

set_schema do
  primary_key :id
  Time :opening_hour   # type is :datetime
  time :opening_hour   # type is :time

I wish I could use HTML5 date/time fields, but they are not implemented in many browsers yet, and it does not allow to ask for a specific format, which is a not really nice.


Regarding the :attachment type, it should be able to work with any kind of system. We made it simple and customizable enough to adapt to many attachment solutions. I called it :attachment because I never really use blobs, but it might be used with blobs as well. Once again because it is very basic.

This is typically the kind of field that cannot really be guessed by crushyform. So you have to declare it as an :attachment. We see how it is done in the following chapter.

Also when it can, crushyform tries to put a thumbnail of the attachment, above the file input when possible. It is done with an instance method that can be overriden by you: Model#to_thumb( column ). By default, it does the right job if you're using another Gem we've done called Stash-Magic . Otherwise crushyform assumes that the column contains the relative URL of an image.


The :parent field type is quite straight foreward and there is not much to say in order to be able to use it. It is interesting to see how it works though. You have a dropdown with all parents name instead of just a crude ID number. One interesting thing is that this dropdown is available for you to use for an Ajax update or whatever:

Author.to_dropdown( 3, "Choose your Author" )

Both options are optional. The first one is the ID of the author that is selected (default is nil). And the second option is the text for the nil option (default is "** UNDEFINED **").

This dropdown is cached in Model::dropdown_cache and is automatically reseted when you create, update or destroy an entry. Alternatively, you can do it with Model::reset_dropdown_cache.

Another interesting thing is the way crushyform comes up with names. You rarely would have to do anything because it maintains an ordered list of columns that are appropriate for a name. The current list is in a constant:

LABEL_COLUMNS = [:title, :label, :fullname, :full_name, :surname, :lastname, :last_name, :name, :firstname, :first_name, :caption, :reference, :file_name, :body]

In the worst case scenario, if it cannot find a column, crushyform will call it with the class name followed by the ID number.

Alternatively, you can specify your own column:

Author.label_column = :my_label_column

Or you can override the final instance method Model::to_label:

def to_label

The good thing is that this method is very useful in many places of CMS of your application, and even the front end:


It could even work with addresses. Crushyform turns a multi-line text in a one liner if it is the label column.

# Say the class Address has a column called :body which is the last choice for a label in LABEL_COLUMNS
# 4, Virginia Street
# Flat C

@address.to_label # => 4, Virginia Street Flat C

You get the idea.


This basically the kind of field you want when you have a text field but people are limited to a dropdown list of options. Parent field could be in that category in fact. That is a Fixnum, but limited to available foreign keys. Another example would be a list like your Favourite editor in a list:

  • Emacs
  • Vi
  • Ed
  • Sam
  • Other

To achieve that, you can set something like that:

class Profile < ::Sequel::Model
	  plugin :schema
	  set_schema do
	    primary_key :id
	    String :fave_editor, :crushyform=>{ :type=>:select, :select_options=>['Emacs', 'Vi', 'Ed', 'Sam', 'Other'] }

This will create an appropriate dropdown instead of textfield. But the value is also what people see. Maybe you want to display the name of an editor, but what you want to record is a score from 0 to 10. This is not necessarily an integer as the purpose is just to show you how you make a dropdown with values different from what is displayed:

class Profile < ::Sequel::Model
	  plugin :schema
	  set_schema do
	    primary_key :id
	    Fixnum :how_much_you_worth, :crushyform=>{ :type=>:select, :select_options=>[['Emacs',5], ['Vi',5], ['Ed',10], ['Sam',9], ['Other', 0]] }

You simply put a key/value Array instead of the bare value. Pretty straight forward. And you can also provide the name of an instance method instead as you might want an Array with dynamic content:

class Profile < ::Sequel::Model
	  plugin :schema
	  set_schema do
	    primary_key :id
	    String :hero, :crushyform=>{ :type=>:select, :select_options=> :draw_me_a_list }
	  def draw_me_a_list
	    # Produce an Array dynamically

That's all.


So now some people might think that this is weird that you have to put the options each time you ask for a field. Well, the good news is that you don't. Most of the options on Model#crushyfield are just for specific cases where you want to override/force something. Instead you have a crushyform_schema:

# returns something like:
# {
#   :title => { :type => :string },
#   :body => { :type => :text },
#   :created_on => { :type => :date },
#   :picture => { :type => :string }
# }

As you can see, it is already filled for you with the bare minimum. Unfortunately the picture is a string, but a string that is really an image URL. You can fix that with:

BlogPost.crushyform_schema[:picture].update({ :type => :attachment })

Alright now when you ask for the form or just the :picture field, it is gonna be an file upload field. But you also want the :title to be displayed as a mandatory field:

BlogPost.crushyform_schema[:title].update({ :required => true })

You get the idea.

But there is even a better way if you use the :schema plugin at the same time. You can add an option called :crushyform for each column. For instance, in order to do the same thing as before:

class BlogPost < ::Sequel::Model
  plugin :schema
  plugin :crushyform
  set_schema do
	    primary_key :id
	    String :title, :crushyform => {:required => true}
	    text :body
	    Date :created_on
	    String :picture, :crushyform => {:type => :attachment}
	  create_table unless table_exists?


You can obviously create a type of field that is not implemented in crushyform. If this is a useful one, it is probably better to fork the project on Github and send me a pull request. That way, you'll help crushyform being more interesting.

Otherwise, the list of types is a Hash. Key is the name, and the value is a Proc with a couple of arguments. A dummy example could be:

  :dummy_type => proc do |instance, column_name, options|
    "<p>You cannot change column: #{column_name}</p>"

So it returns a string. Pretty simple.


0.0.1 First version 0.0.2 Use HTML5 attribute required 0.0.3 Fix a bug on the default value for label :name 0.0.4 Fix type :none 0.0.5 Crushyform method guesses the enctype 0.0.6 Human name for classes and label for new records 0.0.7 Fix Model#to_label 0.0.8 Fix bug with apostrophe in text fields 0.1.0 Add :select type and make :parent type overridable through set_schema 0.1.1 Use strftime fordate/time (do not know why I did not !!!) 0.1.2 Monkey patch, just prevent to have text areas instead of text fields when using PostgreSQL 0.1.3 Still use the @schema value for :text type when :schema plugin is used 0.1.4 Do not raise when there is a mismatch between db_schema and schema


(c) 2011 Mickael Riga - see file LICENSE for details


A Sequel plugin that helps building forms







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