Class: WWW::Mechanize::Form

Inherits:
Object
  • Object
show all
Defined in:
lib/www/mechanize/form.rb,
lib/www/mechanize/inspect.rb,
lib/www/mechanize/form/field.rb,
lib/www/mechanize/form/button.rb,
lib/www/mechanize/form/option.rb,
lib/www/mechanize/monkey_patch.rb,
lib/www/mechanize/form/check_box.rb,
lib/www/mechanize/form/file_upload.rb,
lib/www/mechanize/form/select_list.rb,
lib/www/mechanize/form/image_button.rb,
lib/www/mechanize/form/radio_button.rb,
lib/www/mechanize/form/multi_select_list.rb

Overview

Synopsis

This class encapsulates a form parsed out of an HTML page. Each type of input fields available in a form can be accessed through this object. See GlobalForm for more methods.

Example

Find a form and print out its fields

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

Set the input field ‘name’ to “Aaron”

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

Defined Under Namespace

Classes: Button, CheckBox, Field, FileUpload, ImageButton, MultiSelectList, Option, RadioButton, SelectList

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node, mech = nil, page = nil) ⇒ Form

Returns a new instance of Form.



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# File 'lib/www/mechanize/form.rb', line 36

def initialize(node, mech=nil, page=nil)
  @enctype = node['enctype'] || 'application/x-www-form-urlencoded'
  @form_node        = node
  @action           = Util.html_unescape(node['action'])
  @method           = (node['method'] || 'GET').upcase
  @name             = node['name']
  @clicked_buttons  = []
  @page             = page
  @mech             = mech

  parse
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(id, *args) ⇒ Object

Treat form fields like accessors.



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# File 'lib/www/mechanize/form.rb', line 119

def method_missing(id,*args)
  method = id.to_s.gsub(/=$/, '')
  if field(method)
    return field(method).value if args.empty?
    return field(method).value = args[0]
  end
  super
end

Instance Attribute Details

#action ⇒ Object

Returns the value of attribute action.



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# File 'lib/www/mechanize/form.rb', line 26

def action
  @action
end

#buttons ⇒ Object (readonly)

Returns the value of attribute buttons.



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# File 'lib/www/mechanize/form.rb', line 28

def buttons
  @buttons
end

#checkboxes ⇒ Object (readonly)

Returns the value of attribute checkboxes.



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# File 'lib/www/mechanize/form.rb', line 28

def checkboxes
  @checkboxes
end

#enctype ⇒ Object

Returns the value of attribute enctype.



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# File 'lib/www/mechanize/form.rb', line 29

def enctype
  @enctype
end

#fields ⇒ Object (readonly) Also known as: elements

Returns the value of attribute fields.



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# File 'lib/www/mechanize/form.rb', line 28

def fields
  @fields
end

#file_uploads ⇒ Object (readonly)

Returns the value of attribute file_uploads.



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# File 'lib/www/mechanize/form.rb', line 28

def file_uploads
  @file_uploads
end

#form_node ⇒ Object (readonly)

Returns the value of attribute form_node.



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# File 'lib/www/mechanize/form.rb', line 33

def form_node
  @form_node
end

#method ⇒ Object

Returns the value of attribute method.



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# File 'lib/www/mechanize/form.rb', line 26

def method
  @method
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/www/mechanize/form.rb', line 26

def name
  @name
end

#page ⇒ Object (readonly)

Returns the value of attribute page.



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# File 'lib/www/mechanize/form.rb', line 34

def page
  @page
end

#radiobuttons ⇒ Object (readonly)

Returns the value of attribute radiobuttons.



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# File 'lib/www/mechanize/form.rb', line 28

def radiobuttons
  @radiobuttons
end

Instance Method Details

#[](field_name) ⇒ Object

Fetch the value of the first input field with the name passed in

Example

Fetch the value set in the input field ‘name’

puts form['name']



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# File 'lib/www/mechanize/form.rb', line 100

def [](field_name)
  f = field(field_name)
  f && f.value
end

#[]=(field_name, value) ⇒ Object

Set the value of the first input field with the name passed in

Example

Set the value in the input field ‘name’ to “Aaron”

form['name'] = 'Aaron'



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# File 'lib/www/mechanize/form.rb', line 109

def []=(field_name, value)
  f = field(field_name)
  if f.nil?
    add_field!(field_name, value)
  else
    f.value = value
  end
end

#add_button_to_query(button) ⇒ Object

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



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# File 'lib/www/mechanize/form.rb', line 205

def add_button_to_query(button)
  @clicked_buttons << button
end

#add_field!(field_name, value = nil) ⇒ Object

Add a field with field_name and value



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# File 'lib/www/mechanize/form.rb', line 65

def add_field!(field_name, value = nil)
  fields << Field.new(field_name, value)
end

#build_query(buttons = []) ⇒ Object

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.



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# File 'lib/www/mechanize/form.rb', line 161

def build_query(buttons = [])
  query = []
    
  fields().each do |f|
    qval = proc_query(f)
    query.push(*qval)
  end
    
  checkboxes().each do |f|
    if f.checked
      qval = proc_query(f)
      query.push(*qval)
    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.size == 1
      f = checked.first
      qval = proc_query(f)
      query.push(*qval)
    elsif checked.size > 1 
      raise "multiple radiobuttons are checked in the same group!" 
    end
  end

  @clicked_buttons.each { |b|
    qval = proc_query(b)
    query.push(*qval)
  }
  query
end

#click_button(button = buttons.first) ⇒ Object

Submit form using button. Defaults to the first button.



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# File 'lib/www/mechanize/form.rb', line 135

def click_button(button = buttons.first)
  submit(button)
end

#delete_field!(field_name) ⇒ Object

Removes all fields with name field_name.



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# File 'lib/www/mechanize/form.rb', line 229

def delete_field!(field_name)
  @fields.delete_if{ |f| f.name == field_name}
end

#has_field?(field_name) ⇒ Boolean Also known as: has_key?

Returns whether or not the form contains a field with field_name

Returns:

  • (Boolean) 


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# File 'lib/www/mechanize/form.rb', line 50

def has_field?(field_name)
  ! fields.find { |f| f.name.eql? field_name }.nil?
end

#has_value?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/www/mechanize/form.rb', line 56

def has_value?(value)
  ! fields.find { |f| f.value.eql? value }.nil?
end

#keys ⇒ Object 



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# File 'lib/www/mechanize/form.rb', line 60

def keys; fields.map { |f| f.name }; end

#pretty_print(q) ⇒ Object 



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# File 'lib/www/mechanize/inspect.rb', line 56

def pretty_print(q)
  q.object_group(self) {
    q.breakable; q.group(1, '{name', '}') { q.breakable; q.pp name }
    q.breakable; q.group(1, '{method', '}') { q.breakable; q.pp method }
    q.breakable; q.group(1, '{action', '}') { q.breakable; q.pp action }
    q.breakable; q.group(1, '{fields', '}') {
      fields.each do |field|
        q.breakable
        q.pp field
      end
    }
    q.breakable; q.group(1, '{radiobuttons', '}') {
      radiobuttons.each { |b| q.breakable; q.pp b }
    }
    q.breakable; q.group(1, '{checkboxes', '}') {
      checkboxes.each { |b| q.breakable; q.pp b }
    }
    q.breakable; q.group(1, '{file_uploads', '}') {
      file_uploads.each { |b| q.breakable; q.pp b }
    }
    q.breakable; q.group(1, '{buttons', '}') {
      buttons.each { |b| q.breakable; q.pp b }
    }
  }
end

#request_data ⇒ Object

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,



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# File 'lib/www/mechanize/form.rb', line 212

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.each { |k,v| params << param_to_multipart(k, v) unless k.nil? }
    @file_uploads.each { |f| params << file_to_multipart(f) }
    params.collect { |p| "--#{boundary}\r\n#{p}" }.join('') +
      "--#{boundary}--\r\n"
  else
    WWW::Mechanize::Util.build_query_string(query_params)
  end
end

#set_fields(fields = {}) ⇒ Object

This method sets multiple fields on the form. It takes a list of field 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' } )



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# File 'lib/www/mechanize/form.rb', line 77

def set_fields(fields = {})
  fields.each do |k,v|
    case v
    when Hash
      v.each do |index, value|
        self.fields_with(:name => k.to_s).[](index).value = value
      end
    else
      value = nil
      index = 0
      [v].flatten.each do |val|
        index = val.to_i unless value.nil?
        value = val if value.nil?
      end
      self.fields_with(:name => k.to_s).[](index).value = value
    end
  end
end

#submit(button = nil, headers = {}) ⇒ Object

Submit this form with the button passed in



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# File 'lib/www/mechanize/form.rb', line 129

def submit button=nil, headers = {}
  @mech.submit(self, button, headers)
end

#values ⇒ Object 



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# File 'lib/www/mechanize/form.rb', line 62

def values; fields.map { |f| f.value }; end