title: how to get records into wizard from the current form view in odoo?
body: <p>i have added a button called return in purchase order form view which display a wizard view that i can get products to it to be returned, all is working good, but i need to know how can i get the product of self PO lines,</p>
  
  <pre><code>class returnfromorder(models.TransientModel):
  _name = 'returnfromorder'
  
  
  picking_id = fields.Many2one('stock.picking')
  product_return_moves = fields.One2many('stock.return.picking.line', 'wizard_id', 'Moves')
  move_dest_exists = fields.Boolean('Chained Move Exists', readonly=True)
  original_location_id = fields.Many2one('stock.location')
  parent_location_id = fields.Many2one('stock.location')
  location_id = fields.Many2one(
      'stock.location', 'Return Location',
      domain="['|', ('id', '=', original_location_id), ('return_location', '=', True)]")
  
  @api.multi
  def buto(self):
      products=self.env['purchase.order'].order_line
      for product in products.search([]):
          pro = product.product_id
          print(pro)
  </code></pre>
  
  <p>i'am using the methode buto in a button in form view so i can test and print the values before working to add them in lines </p>
  
  <p>here is XML </p>
  
  <pre><code>    &lt;!-- Inherit Form View to Modify it --&gt;
      &lt;record id="wizard_return_form" model="ir.ui.view"&gt;
          &lt;field name="name"&gt;wizard.return.form&lt;/field&gt;
          &lt;field name="model"&gt;returnfromorder&lt;/field&gt;
          &lt;field name="arch" type="xml"&gt;
              &lt;form string="return"&gt;
                  &lt;sheet&gt;
                      &lt;group&gt;
                          &lt;field name="picking_id"/&gt;
                          &lt;field name="product_return_moves"/&gt;
                          &lt;field name="move_dest_exists"/&gt;
                          &lt;field name="original_location_id"/&gt;
                          &lt;field name="parent_location_id"/&gt;
                          &lt;field name="location_id"/&gt;
                          &lt;button name="buto" class="oe_highlight" type="object" string="ObjectButton"/&gt;
                      &lt;/group&gt;
                  &lt;/sheet&gt;
                  &lt;footer&gt;
                      &lt;button string="Skip" class="btn-secondary" special="cancel"/&gt;
                  &lt;/footer&gt;
              &lt;/form&gt;
          &lt;/field&gt;
      &lt;/record&gt;
  
      &lt;act_window id="return_wizard"
                  name="Add return"
                  res_model="returnfromorder"
                  view_mode="form"
                  target="new"
                  view_id="wizard_return_form"
      /&gt;
  </code></pre>
  
  <p>any help will be appreciated </p>