Module | ActionView::Helpers::ActiveRecordHelper |
In: |
vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb
|
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
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 specialized to include both a prepend_text and append_text to properly introduce the error and a css_class to style it accordingly. Examples (post has an error message "can’t be empty" 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>
# File vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb, line 87 87: def error_message_on(object, method, prepend_text = "", append_text = "", css_class = "formError") 88: if errors = instance_variable_get("@#{object}").errors.on(method) 89: content_tag("div", "#{prepend_text}#{errors.is_a?(Array) ? errors.first : errors}#{append_text}", :class => css_class) 90: end 91: end
Returns a string with a div containing all the error messages for the object located as an instance variable by the name of object_name. This div can be tailored by the following options:
# File vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb, line 99 99: def error_messages_for(object_name, options = {}) 100: options = options.symbolize_keys 101: object = instance_variable_get("@#{object_name}") 102: unless object.errors.empty? 103: content_tag("div", 104: content_tag( 105: options[:header_tag] || "h2", 106: "#{pluralize(object.errors.count, "error")} prohibited this #{object_name.to_s.gsub("_", " ")} from being saved" 107: ) + 108: content_tag("p", "There were problems with the following fields:") + 109: content_tag("ul", object.errors.full_messages.collect { |msg| content_tag("li", msg) }), 110: "id" => options[:id] || "errorExplanation", "class" => options[:class] || "errorExplanation" 111: ) 112: end 113: end
Returns an entire form with input tags and everything for a specified Active Record object. Example (post is a new record that has a title using VARCHAR and a body using TEXT):
form("post") => <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"> Back to the hill and over it again! </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. Example (entry is a new record that has a message attribute using 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
# File vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb, line 59 59: def form(record_name, options = {}) 60: record = instance_variable_get("@#{record_name}") 61: 62: options = options.symbolize_keys 63: options[:action] ||= record.new_record? ? "create" : "update" 64: action = url_for(:action => options[:action], :id => record) 65: 66: submit_value = options[:submit_value] || options[:action].gsub(/[^\w]/, '').capitalize 67: 68: contents = '' 69: contents << hidden_field(record_name, :id) unless record.new_record? 70: contents << all_input_tags(record, record_name, options) 71: yield contents if block_given? 72: contents << submit_tag(submit_value) 73: 74: content_tag('form', contents, :action => action, :method => 'post') 75: end
Returns a default input tag for the type of object returned by the method. Example (title is a VARCHAR column and holds "Hello World"):
input("post", "title") => <input id="post_title" name="post[title]" size="30" type="text" value="Hello World" />
# File vendor/rails/actionpack/lib/action_view/helpers/active_record_helper.rb, line 20 20: def input(record_name, method) 21: InstanceTag.new(record_name, method, self).to_tag 22: end