Module: ActionView::Helpers::ActiveRecordHelper
- Defined in:
- lib/action_view/helpers/active_record_helper.rb
Overview
The Active Record Helper makes it easier to create forms for records kept in instance variables. The most far-reaching is the form method that creates a complete form for all the basic content types of the record (not associations or aggregations, though). This is a great of making the record quickly available for editing, but likely to prove lackluster for a complicated real-world form. In that case, it’s better to use the input method and the specialized form methods in classes/ActionView/Helpers/FormHelper.html
Instance Method Summary collapse
-
#error_message_on(object, method, prepend_text = "", append_text = "", css_class = "formError") ⇒ Object
Returns a string containing the error message attached to the
method
on theobject
if one exists. -
#error_messages_for(*params) ⇒ Object
Returns a string with a
DIV
containing all of the error messages for the objects located as instance variables by the names given. -
#form(record_name, options = {}) {|contents| ... } ⇒ Object
Returns an entire form with all needed input tags for a specified Active Record object.
-
#input(record_name, method, options = {}) ⇒ Object
Returns a default input tag for the type of object returned by the method.
Instance Method Details
#error_message_on(object, method, prepend_text = "", append_text = "", css_class = "formError") ⇒ Object
Returns a string containing the error message attached to the method
on the object
if one exists. This error message is wrapped in a DIV
tag, which can be extended to include a prepend_text
and/or append_text
(to properly explain the error), and a css_class
to style it accordingly. As an example, let’s say you have a model post
that has an error message on the title
attribute:
<%= error_message_on "post", "title" %> =>
<div class="formError">can't be empty</div>
<%= error_message_on "post", "title", "Title simply ", " (or it won't work).", "inputError" %> =>
<div class="inputError">Title simply can't be empty (or it won't work).</div>
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# File 'lib/action_view/helpers/active_record_helper.rb', line 87 def (object, method, prepend_text = "", append_text = "", css_class = "formError") if (obj = instance_variable_get("@#{object}")) && (errors = obj.errors.on(method)) content_tag("div", "#{prepend_text}#{errors.is_a?(Array) ? errors.first : errors}#{append_text}", :class => css_class) else '' end end |
#error_messages_for(*params) ⇒ Object
Returns a string with a DIV
containing all of the error messages for the objects located as instance variables by the names given. If more than one object is specified, the errors for the objects are displayed in the order that the object names are provided.
This DIV
can be tailored by the following options:
-
header_tag
- Used for the header of the error div (default: h2) -
id
- The id of the error div (default: errorExplanation) -
class
- The class of the error div (default: errorExplanation) -
object_name
- The object name to use in the header, or
any text that you prefer. If object_name
is not set, the name of the first object will be used.
To specify the display for one object, you simply provide its name as a parameter. For example, for the User
model:
'user'
To specify more than one object, you simply list them; optionally, you can add an extra object_name
parameter, which be the name in the header.
'user_common', 'user', :object_name => 'user'
NOTE: This is a pre-packaged presentation of the errors with embedded strings and a certain HTML structure. If what you need is significantly different from the default presentation, it makes plenty of sense to access the object.errors instance yourself and set it up. View the source of this method to see how easy it is.
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# File 'lib/action_view/helpers/active_record_helper.rb', line 120 def (*params) = params.last.is_a?(Hash) ? params.pop.symbolize_keys : {} objects = params.collect {|object_name| instance_variable_get("@#{object_name}") }.compact count = objects.inject(0) {|sum, object| sum + object.errors.count } unless count.zero? html = {} [:id, :class].each do |key| if .include?(key) value = [key] html[key] = value unless value.blank? else html[key] = 'errorExplanation' end end = "#{pluralize(count, 'error')} prohibited this #{([:object_name] || params.first).to_s.gsub('_', ' ')} from being saved" = objects.map {|object| object.errors..map {|msg| content_tag(:li, msg) } } content_tag(:div, content_tag([:header_tag] || :h2, ) << content_tag(:p, 'There were problems with the following fields:') << content_tag(:ul, ), html ) else '' end end |
#form(record_name, options = {}) {|contents| ... } ⇒ Object
Returns an entire form with all needed input tags for a specified Active Record object. For example, let’s say you have a table model Post
with attributes named title
of type VARCHAR
and body
of type TEXT
:
form("post")
That line would yield a form like the following:
<form action='/post/create' method='post'>
<p>
<label for="post_title">Title</label><br />
<input id="post_title" name="post[title]" size="30" type="text" value="Hello World" />
</p>
<p>
<label for="post_body">Body</label><br />
<textarea cols="40" id="post_body" name="post[body]" rows="20">
</textarea>
</p>
<input type='submit' value='Create' />
</form>
It’s possible to specialize the form builder by using a different action name and by supplying another block renderer. For example, let’s say you have a model Entry
with an attribute message
of type VARCHAR
:
form("entry", :action => "sign", :input_block =>
Proc.new { |record, column| "#{column.human_name}: #{input(record, column.name)}<br />" }) =>
<form action='/post/sign' method='post'>
Message:
<input id="post_title" name="post[title]" size="30" type="text" value="Hello World" /><br />
<input type='submit' value='Sign' />
</form>
It’s also possible to add additional content to the form by giving it a block, such as:
form("entry", :action => "sign") do |form|
form << content_tag("b", "Department")
form << collection_select("department", "id", @departments, "id", "name")
end
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# File 'lib/action_view/helpers/active_record_helper.rb', line 59 def form(record_name, = {}) record = instance_variable_get("@#{record_name}") = .symbolize_keys [:action] ||= record.new_record? ? "create" : "update" action = url_for(:action => [:action], :id => record) submit_value = [:submit_value] || [:action].gsub(/[^\w]/, '').capitalize contents = '' contents << hidden_field(record_name, :id) unless record.new_record? contents << (record, record_name, ) yield contents if block_given? contents << submit_tag(submit_value) content_tag('form', contents, :action => action, :method => 'post', :enctype => [:multipart] ? 'multipart/form-data': nil) end |
#input(record_name, method, options = {}) ⇒ Object
Returns a default input tag for the type of object returned by the method. For example, let’s say you have a model that has an attribute title
of type VARCHAR column, and this instance holds “Hello World”:
input("post", "title") =>
<input id="post_title" name="post[title]" size="30" type="text" value="Hello World" />
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# File 'lib/action_view/helpers/active_record_helper.rb', line 20 def input(record_name, method, = {}) InstanceTag.new(record_name, method, self).to_tag() end |