class Mechanize::Form

This class encapsulates a form parsed out of an HTML page. Each type of input field available in a form can be accessed through this object.

Examples¶ ↑

Find a form and print out its fields

form = page.forms.first # => Mechanize::Form
form.fields.each { |f| puts f.name }

Set the input field 'name' to “Aaron”

form['name'] = 'Aaron'
puts form['name']

Attributes

action[RW]

buttons[R]

checkboxes[R]

elements[R]

encoding[RW]

Character encoding of form data (i.e. UTF-8)

enctype[RW]

Content-Type for form data (i.e. application/x-www-form-urlencoded)

fields[R]

file_uploads[R]

form_node[R]

ignore_encoding_error[RW]

When true, character encoding errors will never be never raised on form submission. Default is false

method[RW]

name[RW]

page[R]

radiobuttons[R]

Public Class Methods

new(node, mech = nil, page = nil) click to toggle source

# File lib/mechanize/form.rb, line 41
def initialize(node, mech = nil, page = nil)
  @enctype = node['enctype'] || 'application/x-www-form-urlencoded'
  @form_node        = node
  @action           = Mechanize::Util.html_unescape(node['action'])
  @method           = (node['method'] || 'GET').upcase
  @name             = node['name']
  @clicked_buttons  = []
  @page             = page
  @mech             = mech

  @encoding = node['accept-charset'] || (page && page.encoding) || nil
  @ignore_encoding_error = false
  parse
end

Public Instance Methods

[](field_name) click to toggle source

Fetch the value of the first input field with the name passed in. Example:

puts form['name']

# File lib/mechanize/form.rb, line 192
def [](field_name)
  f = field(field_name)
  f && f.value
end

[]=(field_name, value) click to toggle source

Set the value of the first input field with the name passed in. Example:

form['name'] = 'Aaron'

# File lib/mechanize/form.rb, line 199
def []=(field_name, value)
  f = field(field_name)
  if f
    f.value = value
  else
    add_field!(field_name, value)
  end
end

add_button_to_query(button) click to toggle source

This method adds a button to the query. If the form needs to be submitted with multiple buttons, pass each button to this method.

# File lib/mechanize/form.rb, line 321
def add_button_to_query(button)
  unless button.node.document == @form_node.document then
    message =
      "#{button.inspect} does not belong to the same page as "          "the form #{@name.inspect} in #{@page.uri}"

    raise ArgumentError, message
  end

  @clicked_buttons << button
end

add_field!(field_name, value = nil) click to toggle source

Add a field with field_name and value

# File lib/mechanize/form.rb, line 152
def add_field!(field_name, value = nil)
  fields << Field.new({'name' => field_name}, value)
end

build_query(buttons = []) click to toggle source

This method builds an array of arrays that represent the query parameters to be used with this form. The return value can then be used to create a query string for this form.

# File lib/mechanize/form.rb, line 251
def build_query(buttons = [])
  query = []
  @mech.log.info("form encoding: #{encoding}") if @mech && @mech.log

  save_hash_field_order

  successful_controls = []

  (fields + checkboxes + submits).reject do |f|
    f.node["disabled"]
  end.sort.each do |f|
    case f
    when Mechanize::Form::CheckBox
      if f.checked
        successful_controls << f
      end
    when Mechanize::Form::Field
      successful_controls << f
    end
  end

  radio_groups = {}
  radiobuttons.each do |f|
    fname = from_native_charset(f.name)
    radio_groups[fname] ||= []
    radio_groups[fname] << f
  end

  # take one radio button from each group
  radio_groups.each_value do |g|
    checked = g.select {|f| f.checked}

    if checked.uniq.size > 1 then
      values = checked.map { |button| button.value }.join(', ').inspect
      name = checked.first.name.inspect
      raise Mechanize::Error,
            "radiobuttons #{values} are checked in the #{name} group, "                "only one is allowed"
    else
      successful_controls << checked.first unless checked.empty?
    end
  end

  @clicked_buttons.each { |b|
    successful_controls << b
  }

  successful_controls.sort.each do |ctrl| # DOM order
    qval = proc_query(ctrl)
    query.push(*qval)
  end

  query
end

button_with!(criteria)() click to toggle source

Same as button_with but raises an ElementNotFoundError if no button matches criteria

# File lib/mechanize/form.rb, line 408

button_with(criteria)() click to toggle source

Find one button that matches criteria Example:

form.button_with(:value => /submit/).value = 'hello'

# File lib/mechanize/form.rb, line 402

buttons_with(criteria)() click to toggle source

Find all buttons that match criteria Example:

form.buttons_with(:value => /submit/).each do |button|
  button.value = 'hello!'
end

# File lib/mechanize/form.rb, line 417
elements_with :button

checkbox_with(criteria)() click to toggle source

Find one checkbox that matches criteria Example:

form.checkbox_with(:name => /woo/).check

# File lib/mechanize/form.rb, line 474

checkboxes_with(criteria)() click to toggle source

Find all checkboxes that match criteria Example:

form.checkboxes_with(:name => /woo/).each do |field|
  field.check
end

# File lib/mechanize/form.rb, line 489
elements_with :checkbox,   :checkboxes

click_button(button = buttons.first) click to toggle source

Submit form using button. Defaults to the first button.

# File lib/mechanize/form.rb, line 228
def click_button(button = buttons.first)
  submit(button)
end

delete_field!(field_name) click to toggle source

Removes all fields with name field_name.

# File lib/mechanize/form.rb, line 367
def delete_field!(field_name)
  @fields.delete_if{ |f| f.name == field_name}
end

dom_class() click to toggle source

This method is a shortcut to get form's DOM class. Common usage:

page.form_with(:dom_class => "foorm")

Note that you can also use :class to get to this method:

page.form_with(:class => "foorm")

# File lib/mechanize/form.rb, line 147
def dom_class
  form_node['class']
end

dom_id() click to toggle source

This method is a shortcut to get form's DOM id. Common usage:

page.form_with(:dom_id => "foorm")

Note that you can also use :id to get to this method:

page.form_with(:id => "foorm")

# File lib/mechanize/form.rb, line 138
def dom_id
  form_node['id']
end

field_with!(criteria)() click to toggle source

Same as field_with but raises an ElementNotFoundError if no field matches criteria

# File lib/mechanize/form.rb, line 384

field_with(criteria)() click to toggle source

Find one field that matches criteria Example:

form.field_with(:id => "exact_field_id").value = 'hello'

# File lib/mechanize/form.rb, line 378

fields_with(criteria)() click to toggle source

Find all fields that match criteria Example:

form.fields_with(:value => /foo/).each do |field|
  field.value = 'hello!'
end

# File lib/mechanize/form.rb, line 393
elements_with :field

file_upload_with(criteria)() click to toggle source

Find one file upload field that matches criteria Example:

form.file_upload_with(:file_name => /picture/).value = 'foo'

# File lib/mechanize/form.rb, line 426

file_uploads_with(criteria)() click to toggle source

Find all file upload fields that match criteria Example:

form.file_uploads_with(:file_name => /picutre/).each do |field|
  field.value = 'foo!'
end

# File lib/mechanize/form.rb, line 441
elements_with :file_upload

has_field?(field_name) click to toggle source

Returns whether or not the form contains a field with field_name

# File lib/mechanize/form.rb, line 57
def has_field?(field_name)
  fields.find { |f| f.name == field_name }
end

Also aliased as: has_key?

has_key?(field_name)

Alias for: has_field?

has_value?(value) click to toggle source

Returns whether or not the form contains a field with value

# File lib/mechanize/form.rb, line 64
def has_value?(value)
  fields.find { |f| f.value == value }
end

hidden_field?(field_name) click to toggle source

Returns whether or not the form contains a Hidden field named field_name

# File lib/mechanize/form.rb, line 124
def hidden_field?(field_name)
  hiddens.find { |f| f.name == field_name }
end

hiddens() click to toggle source

Returns all fields of type Hidden

# File lib/mechanize/form.rb, line 94
def hiddens
  @hiddens ||= fields.select { |f| f.class == Hidden }
end

keygens() click to toggle source

Returns all fields of type Keygen

# File lib/mechanize/form.rb, line 104
def keygens
  @keygens ||= fields.select { |f| f.class == Keygen }
end

keys() click to toggle source

Returns all field names (keys) for this form

# File lib/mechanize/form.rb, line 69
def keys
  fields.map { |f| f.name }
end

method_missing(meth, *args) click to toggle source

Treat form fields like accessors.

Calls superclass method

# File lib/mechanize/form.rb, line 209
def method_missing(meth, *args)
  method = meth.to_s.gsub(/=$/, '')

  if field(method)
    return field(method).value if args.empty?
    return field(method).value = args[0]
  end

  super
end

radiobutton_with(criteria)() click to toggle source

Find one radio button that matches criteria Example:

form.radiobutton_with(:name => /woo/).check

# File lib/mechanize/form.rb, line 450

radiobuttons_with(criteria)() click to toggle source

Find all radio buttons that match criteria Example:

form.radiobuttons_with(:name => /woo/).each do |field|
  field.check
end

# File lib/mechanize/form.rb, line 465
elements_with :radiobutton

request_data() click to toggle source

This method calculates the request data to be sent back to the server for this form, depending on if this is a regular post, get, or a multi-part post,

# File lib/mechanize/form.rb, line 343
def request_data
  query_params = build_query()

  case @enctype.downcase
  when /^multipart\/form-data/
    boundary = rand_string(20)
    @enctype = "multipart/form-data; boundary=#{boundary}"

    params = query_params.map do |k,v|
      param_to_multipart(k, v) if k
    end.compact

    params.concat @file_uploads.map { |f| file_to_multipart(f) }

    params.map do |part|
      "--#{boundary}\r\n#{part.force_encoding(Encoding::ASCII_8BIT)}"
    end.join('') +
      "--#{boundary}--\r\n"
  else
    Mechanize::Util.build_query_string(query_params)
  end
end

reset() click to toggle source

This method allows the same form to be submitted second time with the different submit button being clicked.

# File lib/mechanize/form.rb, line 335
def reset
  # In the future, should add more functionality here to reset the form values to their defaults.
  @clicked_buttons = []
end

reset_button?(button_name) click to toggle source

Returns whether or not the form contains a Reset button named button_name

# File lib/mechanize/form.rb, line 114
def reset_button?(button_name)
  resets.find { |f| f.name == button_name }
end

resets() click to toggle source

Returns all buttons of type Reset

# File lib/mechanize/form.rb, line 84
def resets
  @resets ||= buttons.select { |f| f.class == Reset }
end

save_hash_field_order() click to toggle source

This method adds an index to all fields that have Hash nodes. This enables field sorting to maintain order.

# File lib/mechanize/form.rb, line 308
def save_hash_field_order
  index = 0

  fields.each do |field|
    if Hash === field.node
      field.index = index
      index += 1
    end
  end
end

set_fields(fields = {}) click to toggle source

This method sets multiple fields on the form. It takes a list of fields which are name, value pairs.

If there is more than one field found with the same name, this method will set the first one found. If you want to set the value of a duplicate field, use a value which is a Hash with the key as the index in to the form. The index is zero based.

For example, to set the second field named 'foo', you could do the following:

form.set_fields :foo => { 1 => 'bar' }

# File lib/mechanize/form.rb, line 169
def set_fields fields = {}
  fields.each do |name, v|
    case v
    when Hash
      v.each do |index, value|
        self.fields_with(:name => name.to_s)[index].value = value
      end
    else
      value = nil
      index = 0

      [v].flatten.each do |val|
        index = val.to_i if value
        value = val unless value
      end

      self.fields_with(:name => name.to_s)[index].value = value
    end
  end
end

submit(button = nil, headers = {}) click to toggle source

Submit the form. Does not include the button as a form parameter. Use click_button or provide button as a parameter.

# File lib/mechanize/form.rb, line 222
def submit button = nil, headers = {}
  @mech.submit(self, button, headers)
end

submit_button?(button_name) click to toggle source

Returns whether or not the form contains a Submit button named button_name

# File lib/mechanize/form.rb, line 109
def submit_button?(button_name)
  submits.find { |f| f.name == button_name }
end

submits() click to toggle source

Returns all buttons of type Submit

# File lib/mechanize/form.rb, line 79
def submits
  @submits ||= buttons.select { |f| f.class == Submit }
end

text_field?(field_name) click to toggle source

Returns whether or not the form contains a Text field named field_name

# File lib/mechanize/form.rb, line 119
def text_field?(field_name)
  texts.find { |f| f.name == field_name }
end

textarea_field?(field_name) click to toggle source

Returns whether or not the form contains a Textarea named field_name

# File lib/mechanize/form.rb, line 129
def textarea_field?(field_name)
  textareas.find { |f| f.name == field_name }
end

textareas() click to toggle source

Returns all fields of type Textarea

# File lib/mechanize/form.rb, line 99
def textareas
  @textareas ||= fields.select { |f| f.class == Textarea }
end

texts() click to toggle source

Returns all fields of type Text

# File lib/mechanize/form.rb, line 89
def texts
  @texts ||= fields.select { |f| f.class == Text }
end

values() click to toggle source

Returns all field values for this form

# File lib/mechanize/form.rb, line 74
def values
  fields.map { |f| f.value }
end